From 3d3eb9b76bf7ce25ae44e513f1196603b2322694 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Schmidt?=
 <9435005+AnSch1510@users.noreply.github.com>
Date: Thu, 18 Jul 2024 13:23:35 +0200
Subject: [PATCH] add unique constrain to User Alias in Database

---
 src/server/data/Entities/UserEntity.cs        |   1 +
 ...40718112149_UserHasUniqueAlias.Designer.cs | 616 ++++++++++++++++++
 .../20240718112149_UserHasUniqueAlias.cs      |  29 +
 .../DatabaseContextModelSnapshot.cs           |   4 +
 ...40718112151_UserHasUniqueAlias.Designer.cs | 614 +++++++++++++++++
 .../20240718112151_UserHasUniqueAlias.cs      |  28 +
 .../DatabaseContextModelSnapshot.cs           |   3 +
 ...40718112146_UserHasUniqueAlias.Designer.cs | 591 +++++++++++++++++
 .../20240718112146_UserHasUniqueAlias.cs      |  28 +
 .../DatabaseContextModelSnapshot.cs           |   3 +
 10 files changed, 1917 insertions(+)
 create mode 100644 src/server/migrations/mssql/Migrations/20240718112149_UserHasUniqueAlias.Designer.cs
 create mode 100644 src/server/migrations/mssql/Migrations/20240718112149_UserHasUniqueAlias.cs
 create mode 100644 src/server/migrations/postgresql/Migrations/20240718112151_UserHasUniqueAlias.Designer.cs
 create mode 100644 src/server/migrations/postgresql/Migrations/20240718112151_UserHasUniqueAlias.cs
 create mode 100644 src/server/migrations/sqlite/Migrations/20240718112146_UserHasUniqueAlias.Designer.cs
 create mode 100644 src/server/migrations/sqlite/Migrations/20240718112146_UserHasUniqueAlias.cs

diff --git a/src/server/data/Entities/UserEntity.cs b/src/server/data/Entities/UserEntity.cs
index 7a09ed0..523b989 100644
--- a/src/server/data/Entities/UserEntity.cs
+++ b/src/server/data/Entities/UserEntity.cs
@@ -58,5 +58,6 @@ public static void Configure(EntityTypeBuilder<UserEntity> builder)
 
         builder.HasKey(x => x.Id);
         builder.HasIndex(x => x.LoginToken).IsUnique();
+        builder.HasIndex(x => x.Alias).IsUnique();
     }
 }
diff --git a/src/server/migrations/mssql/Migrations/20240718112149_UserHasUniqueAlias.Designer.cs b/src/server/migrations/mssql/Migrations/20240718112149_UserHasUniqueAlias.Designer.cs
new file mode 100644
index 0000000..5f4367b
--- /dev/null
+++ b/src/server/migrations/mssql/Migrations/20240718112149_UserHasUniqueAlias.Designer.cs
@@ -0,0 +1,616 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using MinigolfFriday.Data;
+
+#nullable disable
+
+namespace MinigolfFriday.Migrations.MsSql.Migrations
+{
+    [DbContext(typeof(DatabaseContext))]
+    [Migration("20240718112149_UserHasUniqueAlias")]
+    partial class UserHasUniqueAlias
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "8.0.6")
+                .HasAnnotation("Relational:MaxIdentifierLength", 128);
+
+            SqlServerModelBuilderExtensions.UseIdentityColumns(modelBuilder);
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<long>("Id"));
+
+                    b.Property<DateOnly>("Date")
+                        .HasColumnType("date")
+                        .HasColumnName("date");
+
+                    b.Property<DateTimeOffset>("RegistrationDeadline")
+                        .HasColumnType("datetimeoffset")
+                        .HasColumnName("registration_deadline");
+
+                    b.Property<bool>("Staged")
+                        .HasColumnType("bit")
+                        .HasColumnName("staged");
+
+                    b.Property<DateTimeOffset?>("StartedAt")
+                        .HasColumnType("datetimeoffset")
+                        .HasColumnName("started_at");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("events", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstanceEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<long>("Id"));
+
+                    b.Property<string>("GroupCode")
+                        .IsRequired()
+                        .HasMaxLength(20)
+                        .HasColumnType("nvarchar(20)")
+                        .HasColumnName("group_code");
+
+                    b.Property<long>("timeslot_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("timeslot_id");
+
+                    b.ToTable("event_instances", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstancePreconfigurationEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<long>("Id"));
+
+                    b.Property<long>("event_timeslot_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("event_timeslot_id");
+
+                    b.ToTable("event_instance_preconfigurations", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<long>("Id"));
+
+                    b.Property<long>("EventId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("event_id");
+
+                    b.Property<bool>("IsFallbackAllowed")
+                        .HasColumnType("bit")
+                        .HasColumnName("is_fallback_allowed");
+
+                    b.Property<long?>("MapId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("map_id");
+
+                    b.Property<TimeOnly>("Time")
+                        .HasColumnType("time")
+                        .HasColumnName("time");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("MapId");
+
+                    b.HasIndex("EventId", "Time")
+                        .IsUnique();
+
+                    b.ToTable("event_timeslots", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotRegistrationEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<long>("Id"));
+
+                    b.Property<long>("EventTimeslotId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("event_timeslot_id");
+
+                    b.Property<long?>("FallbackEventTimeslotId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("fallback_event_timeslot_id");
+
+                    b.Property<long>("PlayerId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("EventTimeslotId");
+
+                    b.HasIndex("FallbackEventTimeslotId");
+
+                    b.HasIndex("PlayerId");
+
+                    b.ToTable("event_timeslot_registration", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.MinigolfMapEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<long>("Id"));
+
+                    b.Property<bool>("IsActive")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bit")
+                        .HasDefaultValue(true)
+                        .HasColumnName("active");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(150)
+                        .HasColumnType("nvarchar(150)")
+                        .HasColumnName("name");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("maps", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.RoleEntity", b =>
+                {
+                    b.Property<int>("Id")
+                        .HasColumnType("int")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("nvarchar(50)")
+                        .HasColumnName("name");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("roles", (string)null);
+
+                    b.HasData(
+                        new
+                        {
+                            Id = 0,
+                            Name = "Player"
+                        },
+                        new
+                        {
+                            Id = 1,
+                            Name = "Admin"
+                        },
+                        new
+                        {
+                            Id = 2,
+                            Name = "Developer"
+                        });
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<long>("Id"));
+
+                    b.Property<string>("Alias")
+                        .HasMaxLength(150)
+                        .HasColumnType("nvarchar(150)")
+                        .HasColumnName("alias");
+
+                    b.Property<string>("LoginToken")
+                        .HasMaxLength(32)
+                        .HasColumnType("nvarchar(32)")
+                        .HasColumnName("login_token");
+
+                    b.Property<long?>("SettingsId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("settings_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Alias")
+                        .IsUnique()
+                        .HasFilter("[alias] IS NOT NULL");
+
+                    b.HasIndex("LoginToken")
+                        .IsUnique()
+                        .HasFilter("[login_token] IS NOT NULL");
+
+                    b.HasIndex("SettingsId");
+
+                    b.ToTable("users", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserPushSubscriptionEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<long>("Id"));
+
+                    b.Property<string>("Auth")
+                        .HasMaxLength(255)
+                        .HasColumnType("nvarchar(255)")
+                        .HasColumnName("auth");
+
+                    b.Property<string>("Endpoint")
+                        .IsRequired()
+                        .HasMaxLength(2048)
+                        .HasColumnType("nvarchar(2048)")
+                        .HasColumnName("endpoint");
+
+                    b.Property<string>("Lang")
+                        .IsRequired()
+                        .HasMaxLength(10)
+                        .HasColumnType("nvarchar(10)")
+                        .HasColumnName("lang");
+
+                    b.Property<string>("P256DH")
+                        .HasMaxLength(255)
+                        .HasColumnType("nvarchar(255)")
+                        .HasColumnName("p256dh");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Endpoint")
+                        .IsUnique();
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("user_push_subscriptions", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserSettingsEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<long>("Id"));
+
+                    b.Property<bool>("EnableNotifications")
+                        .HasColumnType("bit")
+                        .HasColumnName("enable_notifications");
+
+                    b.Property<bool>("NotifyOnEventPublish")
+                        .HasColumnType("bit")
+                        .HasColumnName("notify_on_event_publish");
+
+                    b.Property<bool>("NotifyOnEventStart")
+                        .HasColumnType("bit")
+                        .HasColumnName("notify_on_event_start");
+
+                    b.Property<bool>("NotifyOnEventUpdated")
+                        .HasColumnType("bit")
+                        .HasColumnName("notify_on_event_updated");
+
+                    b.Property<bool>("NotifyOnTimeslotStart")
+                        .HasColumnType("bit")
+                        .HasColumnName("notify_on_timeslot_start");
+
+                    b.Property<int>("SecondsToNotifyBeforeTimeslotStart")
+                        .HasColumnType("int")
+                        .HasColumnName("seconds_to_notify_before_timeslot_start");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("user_settings", (string)null);
+                });
+
+            modelBuilder.Entity("event_instances_to_users", b =>
+                {
+                    b.Property<long>("event_instance_id")
+                        .HasColumnType("bigint");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("event_instance_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("event_instances_to_users");
+                });
+
+            modelBuilder.Entity("users_to_avoided_users", b =>
+                {
+                    b.Property<long>("avoided_user_id")
+                        .HasColumnType("bigint");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("avoided_user_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_avoided_users");
+                });
+
+            modelBuilder.Entity("users_to_event_instance_preconfigurations", b =>
+                {
+                    b.Property<long>("event_instance_preconfiguration_id")
+                        .HasColumnType("bigint");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("event_instance_preconfiguration_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_event_instance_preconfigurations");
+                });
+
+            modelBuilder.Entity("users_to_preferred_users", b =>
+                {
+                    b.Property<long>("preferred_user_id")
+                        .HasColumnType("bigint");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("preferred_user_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_preferred_users");
+                });
+
+            modelBuilder.Entity("users_to_roles", b =>
+                {
+                    b.Property<int>("role_id")
+                        .HasColumnType("int");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("role_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_roles");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstanceEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "EventTimeslot")
+                        .WithMany("Instances")
+                        .HasForeignKey("timeslot_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("EventTimeslot");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstancePreconfigurationEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "EventTimeSlot")
+                        .WithMany("Preconfigurations")
+                        .HasForeignKey("event_timeslot_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("EventTimeSlot");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventEntity", "Event")
+                        .WithMany("Timeslots")
+                        .HasForeignKey("EventId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.MinigolfMapEntity", "Map")
+                        .WithMany("EventTimeslots")
+                        .HasForeignKey("MapId");
+
+                    b.Navigation("Event");
+
+                    b.Navigation("Map");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotRegistrationEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "EventTimeslot")
+                        .WithMany("Registrations")
+                        .HasForeignKey("EventTimeslotId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "FallbackEventTimeslot")
+                        .WithMany()
+                        .HasForeignKey("FallbackEventTimeslotId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", "Player")
+                        .WithMany()
+                        .HasForeignKey("PlayerId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("EventTimeslot");
+
+                    b.Navigation("FallbackEventTimeslot");
+
+                    b.Navigation("Player");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserSettingsEntity", "Settings")
+                        .WithMany("Users")
+                        .HasForeignKey("SettingsId");
+
+                    b.Navigation("Settings");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserPushSubscriptionEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", "User")
+                        .WithMany("PushSubscriptions")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("event_instances_to_users", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventInstanceEntity", null)
+                        .WithMany()
+                        .HasForeignKey("event_instance_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_avoided_users", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("avoided_user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.ClientCascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_event_instance_preconfigurations", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventInstancePreconfigurationEntity", null)
+                        .WithMany()
+                        .HasForeignKey("event_instance_preconfiguration_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_preferred_users", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("preferred_user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.ClientCascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_roles", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.RoleEntity", null)
+                        .WithMany()
+                        .HasForeignKey("role_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventEntity", b =>
+                {
+                    b.Navigation("Timeslots");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotEntity", b =>
+                {
+                    b.Navigation("Instances");
+
+                    b.Navigation("Preconfigurations");
+
+                    b.Navigation("Registrations");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.MinigolfMapEntity", b =>
+                {
+                    b.Navigation("EventTimeslots");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserEntity", b =>
+                {
+                    b.Navigation("PushSubscriptions");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserSettingsEntity", b =>
+                {
+                    b.Navigation("Users");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/src/server/migrations/mssql/Migrations/20240718112149_UserHasUniqueAlias.cs b/src/server/migrations/mssql/Migrations/20240718112149_UserHasUniqueAlias.cs
new file mode 100644
index 0000000..3af15c5
--- /dev/null
+++ b/src/server/migrations/mssql/Migrations/20240718112149_UserHasUniqueAlias.cs
@@ -0,0 +1,29 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace MinigolfFriday.Migrations.MsSql.Migrations
+{
+    /// <inheritdoc />
+    public partial class UserHasUniqueAlias : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateIndex(
+                name: "IX_users_alias",
+                table: "users",
+                column: "alias",
+                unique: true,
+                filter: "[alias] IS NOT NULL");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropIndex(
+                name: "IX_users_alias",
+                table: "users");
+        }
+    }
+}
diff --git a/src/server/migrations/mssql/Migrations/DatabaseContextModelSnapshot.cs b/src/server/migrations/mssql/Migrations/DatabaseContextModelSnapshot.cs
index 228ef5e..a3eaeca 100644
--- a/src/server/migrations/mssql/Migrations/DatabaseContextModelSnapshot.cs
+++ b/src/server/migrations/mssql/Migrations/DatabaseContextModelSnapshot.cs
@@ -248,6 +248,10 @@ protected override void BuildModel(ModelBuilder modelBuilder)
 
                     b.HasKey("Id");
 
+                    b.HasIndex("Alias")
+                        .IsUnique()
+                        .HasFilter("[alias] IS NOT NULL");
+
                     b.HasIndex("LoginToken")
                         .IsUnique()
                         .HasFilter("[login_token] IS NOT NULL");
diff --git a/src/server/migrations/postgresql/Migrations/20240718112151_UserHasUniqueAlias.Designer.cs b/src/server/migrations/postgresql/Migrations/20240718112151_UserHasUniqueAlias.Designer.cs
new file mode 100644
index 0000000..d4f7a46
--- /dev/null
+++ b/src/server/migrations/postgresql/Migrations/20240718112151_UserHasUniqueAlias.Designer.cs
@@ -0,0 +1,614 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using MinigolfFriday.Data;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace MinigolfFriday.Migrations.PostgreSql.Migrations
+{
+    [DbContext(typeof(DatabaseContext))]
+    [Migration("20240718112151_UserHasUniqueAlias")]
+    partial class UserHasUniqueAlias
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "8.0.6")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateOnly>("Date")
+                        .HasColumnType("date")
+                        .HasColumnName("date");
+
+                    b.Property<DateTimeOffset>("RegistrationDeadline")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("registration_deadline");
+
+                    b.Property<bool>("Staged")
+                        .HasColumnType("boolean")
+                        .HasColumnName("staged");
+
+                    b.Property<DateTimeOffset?>("StartedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("started_at");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("events", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstanceEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<string>("GroupCode")
+                        .IsRequired()
+                        .HasMaxLength(20)
+                        .HasColumnType("character varying(20)")
+                        .HasColumnName("group_code");
+
+                    b.Property<long>("timeslot_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("timeslot_id");
+
+                    b.ToTable("event_instances", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstancePreconfigurationEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<long>("event_timeslot_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("event_timeslot_id");
+
+                    b.ToTable("event_instance_preconfigurations", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<long>("EventId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("event_id");
+
+                    b.Property<bool>("IsFallbackAllowed")
+                        .HasColumnType("boolean")
+                        .HasColumnName("is_fallback_allowed");
+
+                    b.Property<long?>("MapId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("map_id");
+
+                    b.Property<TimeOnly>("Time")
+                        .HasColumnType("time without time zone")
+                        .HasColumnName("time");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("MapId");
+
+                    b.HasIndex("EventId", "Time")
+                        .IsUnique();
+
+                    b.ToTable("event_timeslots", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotRegistrationEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<long>("EventTimeslotId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("event_timeslot_id");
+
+                    b.Property<long?>("FallbackEventTimeslotId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("fallback_event_timeslot_id");
+
+                    b.Property<long>("PlayerId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("EventTimeslotId");
+
+                    b.HasIndex("FallbackEventTimeslotId");
+
+                    b.HasIndex("PlayerId");
+
+                    b.ToTable("event_timeslot_registration", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.MinigolfMapEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<bool>("IsActive")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("boolean")
+                        .HasDefaultValue(true)
+                        .HasColumnName("active");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(150)
+                        .HasColumnType("character varying(150)")
+                        .HasColumnName("name");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("maps", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.RoleEntity", b =>
+                {
+                    b.Property<int>("Id")
+                        .HasColumnType("integer")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)")
+                        .HasColumnName("name");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("roles", (string)null);
+
+                    b.HasData(
+                        new
+                        {
+                            Id = 0,
+                            Name = "Player"
+                        },
+                        new
+                        {
+                            Id = 1,
+                            Name = "Admin"
+                        },
+                        new
+                        {
+                            Id = 2,
+                            Name = "Developer"
+                        });
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<string>("Alias")
+                        .HasMaxLength(150)
+                        .HasColumnType("character varying(150)")
+                        .HasColumnName("alias");
+
+                    b.Property<string>("LoginToken")
+                        .HasMaxLength(32)
+                        .HasColumnType("character varying(32)")
+                        .HasColumnName("login_token");
+
+                    b.Property<long?>("SettingsId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("settings_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Alias")
+                        .IsUnique();
+
+                    b.HasIndex("LoginToken")
+                        .IsUnique();
+
+                    b.HasIndex("SettingsId");
+
+                    b.ToTable("users", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserPushSubscriptionEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<string>("Auth")
+                        .HasMaxLength(255)
+                        .HasColumnType("character varying(255)")
+                        .HasColumnName("auth");
+
+                    b.Property<string>("Endpoint")
+                        .IsRequired()
+                        .HasMaxLength(2048)
+                        .HasColumnType("character varying(2048)")
+                        .HasColumnName("endpoint");
+
+                    b.Property<string>("Lang")
+                        .IsRequired()
+                        .HasMaxLength(10)
+                        .HasColumnType("character varying(10)")
+                        .HasColumnName("lang");
+
+                    b.Property<string>("P256DH")
+                        .HasMaxLength(255)
+                        .HasColumnType("character varying(255)")
+                        .HasColumnName("p256dh");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Endpoint")
+                        .IsUnique();
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("user_push_subscriptions", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserSettingsEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<bool>("EnableNotifications")
+                        .HasColumnType("boolean")
+                        .HasColumnName("enable_notifications");
+
+                    b.Property<bool>("NotifyOnEventPublish")
+                        .HasColumnType("boolean")
+                        .HasColumnName("notify_on_event_publish");
+
+                    b.Property<bool>("NotifyOnEventStart")
+                        .HasColumnType("boolean")
+                        .HasColumnName("notify_on_event_start");
+
+                    b.Property<bool>("NotifyOnEventUpdated")
+                        .HasColumnType("boolean")
+                        .HasColumnName("notify_on_event_updated");
+
+                    b.Property<bool>("NotifyOnTimeslotStart")
+                        .HasColumnType("boolean")
+                        .HasColumnName("notify_on_timeslot_start");
+
+                    b.Property<int>("SecondsToNotifyBeforeTimeslotStart")
+                        .HasColumnType("integer")
+                        .HasColumnName("seconds_to_notify_before_timeslot_start");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("user_settings", (string)null);
+                });
+
+            modelBuilder.Entity("event_instances_to_users", b =>
+                {
+                    b.Property<long>("event_instance_id")
+                        .HasColumnType("bigint");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("event_instance_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("event_instances_to_users");
+                });
+
+            modelBuilder.Entity("users_to_avoided_users", b =>
+                {
+                    b.Property<long>("avoided_user_id")
+                        .HasColumnType("bigint");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("avoided_user_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_avoided_users");
+                });
+
+            modelBuilder.Entity("users_to_event_instance_preconfigurations", b =>
+                {
+                    b.Property<long>("event_instance_preconfiguration_id")
+                        .HasColumnType("bigint");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("event_instance_preconfiguration_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_event_instance_preconfigurations");
+                });
+
+            modelBuilder.Entity("users_to_preferred_users", b =>
+                {
+                    b.Property<long>("preferred_user_id")
+                        .HasColumnType("bigint");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("preferred_user_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_preferred_users");
+                });
+
+            modelBuilder.Entity("users_to_roles", b =>
+                {
+                    b.Property<int>("role_id")
+                        .HasColumnType("integer");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("role_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_roles");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstanceEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "EventTimeslot")
+                        .WithMany("Instances")
+                        .HasForeignKey("timeslot_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("EventTimeslot");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstancePreconfigurationEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "EventTimeSlot")
+                        .WithMany("Preconfigurations")
+                        .HasForeignKey("event_timeslot_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("EventTimeSlot");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventEntity", "Event")
+                        .WithMany("Timeslots")
+                        .HasForeignKey("EventId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.MinigolfMapEntity", "Map")
+                        .WithMany("EventTimeslots")
+                        .HasForeignKey("MapId");
+
+                    b.Navigation("Event");
+
+                    b.Navigation("Map");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotRegistrationEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "EventTimeslot")
+                        .WithMany("Registrations")
+                        .HasForeignKey("EventTimeslotId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "FallbackEventTimeslot")
+                        .WithMany()
+                        .HasForeignKey("FallbackEventTimeslotId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", "Player")
+                        .WithMany()
+                        .HasForeignKey("PlayerId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("EventTimeslot");
+
+                    b.Navigation("FallbackEventTimeslot");
+
+                    b.Navigation("Player");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserSettingsEntity", "Settings")
+                        .WithMany("Users")
+                        .HasForeignKey("SettingsId");
+
+                    b.Navigation("Settings");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserPushSubscriptionEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", "User")
+                        .WithMany("PushSubscriptions")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("event_instances_to_users", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventInstanceEntity", null)
+                        .WithMany()
+                        .HasForeignKey("event_instance_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_avoided_users", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("avoided_user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_event_instance_preconfigurations", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventInstancePreconfigurationEntity", null)
+                        .WithMany()
+                        .HasForeignKey("event_instance_preconfiguration_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_preferred_users", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("preferred_user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_roles", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.RoleEntity", null)
+                        .WithMany()
+                        .HasForeignKey("role_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventEntity", b =>
+                {
+                    b.Navigation("Timeslots");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotEntity", b =>
+                {
+                    b.Navigation("Instances");
+
+                    b.Navigation("Preconfigurations");
+
+                    b.Navigation("Registrations");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.MinigolfMapEntity", b =>
+                {
+                    b.Navigation("EventTimeslots");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserEntity", b =>
+                {
+                    b.Navigation("PushSubscriptions");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserSettingsEntity", b =>
+                {
+                    b.Navigation("Users");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/src/server/migrations/postgresql/Migrations/20240718112151_UserHasUniqueAlias.cs b/src/server/migrations/postgresql/Migrations/20240718112151_UserHasUniqueAlias.cs
new file mode 100644
index 0000000..7d12b5b
--- /dev/null
+++ b/src/server/migrations/postgresql/Migrations/20240718112151_UserHasUniqueAlias.cs
@@ -0,0 +1,28 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace MinigolfFriday.Migrations.PostgreSql.Migrations
+{
+    /// <inheritdoc />
+    public partial class UserHasUniqueAlias : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateIndex(
+                name: "IX_users_alias",
+                table: "users",
+                column: "alias",
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropIndex(
+                name: "IX_users_alias",
+                table: "users");
+        }
+    }
+}
diff --git a/src/server/migrations/postgresql/Migrations/DatabaseContextModelSnapshot.cs b/src/server/migrations/postgresql/Migrations/DatabaseContextModelSnapshot.cs
index cb29ae0..1e1eb74 100644
--- a/src/server/migrations/postgresql/Migrations/DatabaseContextModelSnapshot.cs
+++ b/src/server/migrations/postgresql/Migrations/DatabaseContextModelSnapshot.cs
@@ -248,6 +248,9 @@ protected override void BuildModel(ModelBuilder modelBuilder)
 
                     b.HasKey("Id");
 
+                    b.HasIndex("Alias")
+                        .IsUnique();
+
                     b.HasIndex("LoginToken")
                         .IsUnique();
 
diff --git a/src/server/migrations/sqlite/Migrations/20240718112146_UserHasUniqueAlias.Designer.cs b/src/server/migrations/sqlite/Migrations/20240718112146_UserHasUniqueAlias.Designer.cs
new file mode 100644
index 0000000..b3a2639
--- /dev/null
+++ b/src/server/migrations/sqlite/Migrations/20240718112146_UserHasUniqueAlias.Designer.cs
@@ -0,0 +1,591 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using MinigolfFriday.Data;
+
+#nullable disable
+
+namespace MinigolfFriday.Migrations.Sqlite.Migrations
+{
+    [DbContext(typeof(DatabaseContext))]
+    [Migration("20240718112146_UserHasUniqueAlias")]
+    partial class UserHasUniqueAlias
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "8.0.6");
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("id");
+
+                    b.Property<DateOnly>("Date")
+                        .HasColumnType("TEXT")
+                        .HasColumnName("date");
+
+                    b.Property<DateTimeOffset>("RegistrationDeadline")
+                        .HasColumnType("TEXT")
+                        .HasColumnName("registration_deadline");
+
+                    b.Property<bool>("Staged")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("staged");
+
+                    b.Property<DateTimeOffset?>("StartedAt")
+                        .HasColumnType("TEXT")
+                        .HasColumnName("started_at");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("events", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstanceEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("id");
+
+                    b.Property<string>("GroupCode")
+                        .IsRequired()
+                        .HasMaxLength(20)
+                        .HasColumnType("TEXT")
+                        .HasColumnName("group_code");
+
+                    b.Property<long>("timeslot_id")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("timeslot_id");
+
+                    b.ToTable("event_instances", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstancePreconfigurationEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("id");
+
+                    b.Property<long>("event_timeslot_id")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("event_timeslot_id");
+
+                    b.ToTable("event_instance_preconfigurations", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("id");
+
+                    b.Property<long>("EventId")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("event_id");
+
+                    b.Property<bool>("IsFallbackAllowed")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("is_fallback_allowed");
+
+                    b.Property<long?>("MapId")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("map_id");
+
+                    b.Property<TimeOnly>("Time")
+                        .HasColumnType("TEXT")
+                        .HasColumnName("time");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("MapId");
+
+                    b.HasIndex("EventId", "Time")
+                        .IsUnique();
+
+                    b.ToTable("event_timeslots", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotRegistrationEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("id");
+
+                    b.Property<long>("EventTimeslotId")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("event_timeslot_id");
+
+                    b.Property<long?>("FallbackEventTimeslotId")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("fallback_event_timeslot_id");
+
+                    b.Property<long>("PlayerId")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("EventTimeslotId");
+
+                    b.HasIndex("FallbackEventTimeslotId");
+
+                    b.HasIndex("PlayerId");
+
+                    b.ToTable("event_timeslot_registration", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.MinigolfMapEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("id");
+
+                    b.Property<bool>("IsActive")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(true)
+                        .HasColumnName("active");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(150)
+                        .HasColumnType("TEXT")
+                        .HasColumnName("name");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("maps", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.RoleEntity", b =>
+                {
+                    b.Property<int>("Id")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT")
+                        .HasColumnName("name");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("roles", (string)null);
+
+                    b.HasData(
+                        new
+                        {
+                            Id = 0,
+                            Name = "Player"
+                        },
+                        new
+                        {
+                            Id = 1,
+                            Name = "Admin"
+                        },
+                        new
+                        {
+                            Id = 2,
+                            Name = "Developer"
+                        });
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Alias")
+                        .HasMaxLength(150)
+                        .HasColumnType("TEXT")
+                        .HasColumnName("alias");
+
+                    b.Property<string>("LoginToken")
+                        .HasMaxLength(32)
+                        .HasColumnType("TEXT")
+                        .HasColumnName("login_token");
+
+                    b.Property<long?>("SettingsId")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("settings_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Alias")
+                        .IsUnique();
+
+                    b.HasIndex("LoginToken")
+                        .IsUnique();
+
+                    b.HasIndex("SettingsId");
+
+                    b.ToTable("users", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserPushSubscriptionEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Auth")
+                        .HasMaxLength(255)
+                        .HasColumnType("TEXT")
+                        .HasColumnName("auth");
+
+                    b.Property<string>("Endpoint")
+                        .IsRequired()
+                        .HasMaxLength(2048)
+                        .HasColumnType("TEXT")
+                        .HasColumnName("endpoint");
+
+                    b.Property<string>("Lang")
+                        .IsRequired()
+                        .HasMaxLength(10)
+                        .HasColumnType("TEXT")
+                        .HasColumnName("lang");
+
+                    b.Property<string>("P256DH")
+                        .HasMaxLength(255)
+                        .HasColumnType("TEXT")
+                        .HasColumnName("p256dh");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Endpoint")
+                        .IsUnique();
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("user_push_subscriptions", (string)null);
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserSettingsEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("id");
+
+                    b.Property<bool>("EnableNotifications")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("enable_notifications");
+
+                    b.Property<bool>("NotifyOnEventPublish")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("notify_on_event_publish");
+
+                    b.Property<bool>("NotifyOnEventStart")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("notify_on_event_start");
+
+                    b.Property<bool>("NotifyOnEventUpdated")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("notify_on_event_updated");
+
+                    b.Property<bool>("NotifyOnTimeslotStart")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("notify_on_timeslot_start");
+
+                    b.Property<int>("SecondsToNotifyBeforeTimeslotStart")
+                        .HasColumnType("INTEGER")
+                        .HasColumnName("seconds_to_notify_before_timeslot_start");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("user_settings", (string)null);
+                });
+
+            modelBuilder.Entity("event_instances_to_users", b =>
+                {
+                    b.Property<long>("event_instance_id")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("event_instance_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("event_instances_to_users");
+                });
+
+            modelBuilder.Entity("users_to_avoided_users", b =>
+                {
+                    b.Property<long>("avoided_user_id")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("avoided_user_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_avoided_users");
+                });
+
+            modelBuilder.Entity("users_to_event_instance_preconfigurations", b =>
+                {
+                    b.Property<long>("event_instance_preconfiguration_id")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("event_instance_preconfiguration_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_event_instance_preconfigurations");
+                });
+
+            modelBuilder.Entity("users_to_preferred_users", b =>
+                {
+                    b.Property<long>("preferred_user_id")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("preferred_user_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_preferred_users");
+                });
+
+            modelBuilder.Entity("users_to_roles", b =>
+                {
+                    b.Property<int>("role_id")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("user_id")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("role_id", "user_id");
+
+                    b.HasIndex("user_id");
+
+                    b.ToTable("users_to_roles");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstanceEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "EventTimeslot")
+                        .WithMany("Instances")
+                        .HasForeignKey("timeslot_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("EventTimeslot");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventInstancePreconfigurationEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "EventTimeSlot")
+                        .WithMany("Preconfigurations")
+                        .HasForeignKey("event_timeslot_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("EventTimeSlot");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventEntity", "Event")
+                        .WithMany("Timeslots")
+                        .HasForeignKey("EventId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.MinigolfMapEntity", "Map")
+                        .WithMany("EventTimeslots")
+                        .HasForeignKey("MapId");
+
+                    b.Navigation("Event");
+
+                    b.Navigation("Map");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotRegistrationEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "EventTimeslot")
+                        .WithMany("Registrations")
+                        .HasForeignKey("EventTimeslotId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.EventTimeslotEntity", "FallbackEventTimeslot")
+                        .WithMany()
+                        .HasForeignKey("FallbackEventTimeslotId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", "Player")
+                        .WithMany()
+                        .HasForeignKey("PlayerId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("EventTimeslot");
+
+                    b.Navigation("FallbackEventTimeslot");
+
+                    b.Navigation("Player");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserSettingsEntity", "Settings")
+                        .WithMany("Users")
+                        .HasForeignKey("SettingsId");
+
+                    b.Navigation("Settings");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserPushSubscriptionEntity", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", "User")
+                        .WithMany("PushSubscriptions")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("event_instances_to_users", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventInstanceEntity", null)
+                        .WithMany()
+                        .HasForeignKey("event_instance_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_avoided_users", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("avoided_user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_event_instance_preconfigurations", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.EventInstancePreconfigurationEntity", null)
+                        .WithMany()
+                        .HasForeignKey("event_instance_preconfiguration_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_preferred_users", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("preferred_user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("users_to_roles", b =>
+                {
+                    b.HasOne("MinigolfFriday.Data.Entities.RoleEntity", null)
+                        .WithMany()
+                        .HasForeignKey("role_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("MinigolfFriday.Data.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("user_id")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventEntity", b =>
+                {
+                    b.Navigation("Timeslots");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.EventTimeslotEntity", b =>
+                {
+                    b.Navigation("Instances");
+
+                    b.Navigation("Preconfigurations");
+
+                    b.Navigation("Registrations");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.MinigolfMapEntity", b =>
+                {
+                    b.Navigation("EventTimeslots");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserEntity", b =>
+                {
+                    b.Navigation("PushSubscriptions");
+                });
+
+            modelBuilder.Entity("MinigolfFriday.Data.Entities.UserSettingsEntity", b =>
+                {
+                    b.Navigation("Users");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/src/server/migrations/sqlite/Migrations/20240718112146_UserHasUniqueAlias.cs b/src/server/migrations/sqlite/Migrations/20240718112146_UserHasUniqueAlias.cs
new file mode 100644
index 0000000..aebe127
--- /dev/null
+++ b/src/server/migrations/sqlite/Migrations/20240718112146_UserHasUniqueAlias.cs
@@ -0,0 +1,28 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace MinigolfFriday.Migrations.Sqlite.Migrations
+{
+    /// <inheritdoc />
+    public partial class UserHasUniqueAlias : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateIndex(
+                name: "IX_users_alias",
+                table: "users",
+                column: "alias",
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropIndex(
+                name: "IX_users_alias",
+                table: "users");
+        }
+    }
+}
diff --git a/src/server/migrations/sqlite/Migrations/DatabaseContextModelSnapshot.cs b/src/server/migrations/sqlite/Migrations/DatabaseContextModelSnapshot.cs
index 42cdd2b..f8c8638 100644
--- a/src/server/migrations/sqlite/Migrations/DatabaseContextModelSnapshot.cs
+++ b/src/server/migrations/sqlite/Migrations/DatabaseContextModelSnapshot.cs
@@ -229,6 +229,9 @@ protected override void BuildModel(ModelBuilder modelBuilder)
 
                     b.HasKey("Id");
 
+                    b.HasIndex("Alias")
+                        .IsUnique();
+
                     b.HasIndex("LoginToken")
                         .IsUnique();