Add clickhouse support

.circleci/config.yml

@@ -7,6 +7,7 @@ jobs:
           - DBR_TEST_MYSQL_DSN=root:root@tcp(127.0.0.1:3306)/circle_test
           - DBR_TEST_POSTGRES_DSN=postgres://postgres:[email protected]:5432/postgres?sslmode=disable
           - DBR_TEST_MSSQL_DSN=sqlserver://sa:[email protected]/?database=master
+          - DBR_TEST_CLICKHOUSE_DSN=clickhouse://127.0.0.1:9000
           - GO111MODULE=on
           - FOSSA_API_KEY=486be1298513b278ba3916aa63975d7c
       - image: percona:5.7
@@ -20,6 +21,9 @@ jobs:
         environment:
           - ACCEPT_EULA=Y
           - SA_PASSWORD=qwe123QWE
+      - image: clickhouse/clickhouse-server:23.8.15
+        environment:
+          - CLICKHOUSE_DO_NOT_CHOWN=1
     working_directory: /go/src/github.com/gocraft/dbr
     steps:
       - run: |
@@ -28,6 +32,6 @@ jobs:
       - run: fossa analyze
       - run:
           name: Wait for db
-          command: dockerize -wait tcp://127.0.0.1:3306 -wait tcp://127.0.0.1:5432 -wait tcp://127.0.0.1:1433 -timeout 1m
+          command: dockerize -wait tcp://127.0.0.1:3306 -wait tcp://127.0.0.1:5432 -wait tcp://127.0.0.1:1433 -wait tcp://127.0.0.1:9000 -timeout 1m
       - run: go test -v -cover -bench . ./...
       - run: fossa test

.gitignore

@@ -0,0 +1,9 @@
+# Mac Things
+.DS_Store
+# Goland things
+.idea/
+.vscode/
+# Emacs
+*~
+# Local development directories
+tmp/

README.md

@@ -21,6 +21,7 @@ import "github.com/gocraft/dbr/v2"
 * PostgreSQL
 * SQLite3
 * MsSQL
+* Clickhouse
 
 ## Examples
 
@@ -161,6 +162,7 @@ BenchmarkLoadValues/dbr_100000-8      	      10	 147202536 ns/op	23680625 B/op
 Inspiration from these excellent libraries:
 * [sqlx](https://github.com/jmoiron/sqlx) - various useful tools and utils for interacting with database/sql.
 * [Squirrel](https://github.com/lann/squirrel) - simple fluent query builder.
+* [mailru/dbr](https://github.com/mailru/dbr) - upsert functionality shamelessly and gratefully adapted from this lib.
 
 Authors:
 * Jonathan Novak -- [https://github.com/cypriss](https://github.com/cypriss)

README.md.tpl

@@ -21,6 +21,7 @@ import "github.com/gocraft/dbr/v2"
 * PostgreSQL
 * SQLite3
 * MsSQL
+* Clickhouse
 
 ## Examples
 
@@ -78,6 +79,7 @@ BenchmarkLoadValues/dbr_100000-8      	      10	 147202536 ns/op	23680625 B/op
 Inspiration from these excellent libraries:
 * [sqlx](https://github.com/jmoiron/sqlx) - various useful tools and utils for interacting with database/sql.
 * [Squirrel](https://github.com/lann/squirrel) - simple fluent query builder.
+* [mailru/dbr](https://github.com/mailru/dbr) - upsert functionality shamelessly and gratefully adapted from this lib.
 
 Authors:
 * Jonathan Novak -- [https://github.com/cypriss](https://github.com/cypriss)

branch.go

@@ -0,0 +1,86 @@
+package dbr
+
+// When creates a WHEN statement given a condition and a value that's evaluated
+// if the condition is true.
+func When(cond Builder, value interface{}) Builder {
+	return BuildFunc(func(d Dialect, buf Buffer) error {
+		buf.WriteString("WHEN (")
+		err := cond.Build(d, buf)
+		if err != nil {
+			return err
+		}
+		buf.WriteString(") THEN ")
+
+		builder, ok := value.(Builder)
+		if ok {
+			err = builder.Build(d, buf)
+			if err != nil {
+				return err
+			}
+			return nil
+		}
+
+		buf.WriteString(placeholder)
+		buf.WriteValue(value)
+		return nil
+	})
+}
+
+// Else creates an ELSE statement given a value or a condition.
+func Else(value interface{}) Builder {
+	return BuildFunc(func(d Dialect, buf Buffer) error {
+		buf.WriteString("ELSE ")
+		if builder, ok := value.(Builder); ok {
+			if err := builder.Build(d, buf); err != nil {
+				return err
+			}
+			return nil
+		}
+		buf.WriteString(placeholder)
+		buf.WriteValue(value)
+		return nil
+	})
+}
+
+// Builder interface that includes AS for asliasing CASE statements.
+type CaseBuilder interface {
+	Builder
+	As(name string) Builder
+}
+
+// CaseBuildFunc implements Builder.
+type CaseBuildFunc func(Dialect, Buffer) error
+
+// Case creates a CASE statement from a list of conditions.
+// If there are more than 1 conditions, the last one will be an else statement.
+func Case(conds ...Builder) CaseBuilder {
+	return CaseBuildFunc(func(d Dialect, buf Buffer) error {
+		buf.WriteString("CASE ")
+		l := len(conds)
+		for i, cond := range conds {
+			cond.Build(d, buf)
+			if i < l-1 {
+				buf.WriteString(" ")
+			}
+		}
+		buf.WriteString(" END")
+		return nil
+	})
+}
+
+// AS adds an alias to the CASE statement.
+func (cb CaseBuildFunc) As(alias string) Builder {
+	return BuildFunc(func(d Dialect, buf Buffer) error {
+		if err := cb(d, buf); err != nil {
+			return err
+		}
+		buf.WriteString(" AS ")
+		buf.WriteString(d.QuoteIdent(alias))
+		return nil
+	})
+}
+
+// Build calls itself to build SQL.
+func (cb CaseBuildFunc) Build(d Dialect, buf Buffer) error {
+	return cb(d, buf)
+}

branch_test.go

@@ -0,0 +1,88 @@
+package dbr
+
+import (
+	"testing"
+
+	"github.com/gocraft/dbr/v2/dialect"
+	"github.com/stretchr/testify/require"
+)
+
+func TestWhen(t *testing.T) {
+	for _, test := range []struct {
+		when  Builder
+		query string
+		value []interface{}
+	}{
+		{
+			when:  When(Eq("col", 1), 1),
+			query: "WHEN (`col` = ?) THEN ?",
+			value: []interface{}{1, 1},
+		},
+		{
+			when:  When(And(Gt("a", 1), Lt("b", 2)), "c"),
+			query: "WHEN ((`a` > ?) AND (`b` < ?)) THEN ?",
+			value: []interface{}{1, 2, "c"},
+		},
+		{
+			when:  When(Eq("a", 1), Gt("b", 2)),
+			query: "WHEN (`a` = ?) THEN `b` > ?",
+			value: []interface{}{1, 2},
+		},
+	} {
+		buf := NewBuffer()
+		err := test.when.Build(dialect.Clickhouse, buf)
+		require.NoError(t, err)
+		require.Equal(t, test.query, buf.String())
+		require.Equal(t, test.value, buf.Value())
+	}
+}
+
+func TestCase(t *testing.T) {
+	for _, test := range []struct {
+		caseBuilder Builder
+		query       string
+		value       []interface{}
+	}{
+		{
+			caseBuilder: Case(When(Eq("col", 1), 1)),
+			query:       "CASE WHEN (`col` = ?) THEN ? END",
+			value:       []interface{}{1, 1},
+		},
+		{
+			caseBuilder: Case(When(Eq("col", 1), 1)).As("a"),
+			query:       "CASE WHEN (`col` = ?) THEN ? END AS `a`",
+			value:       []interface{}{1, 1},
+		},
+		{
+			caseBuilder: Case(When(Eq("col", 1), 2), Else(3)),
+			query:       "CASE WHEN (`col` = ?) THEN ? ELSE ? END",
+			value:       []interface{}{1, 2, 3},
+		},
+		{
+			caseBuilder: Case(When(Eq("a", 1), 2), Else(Gt("b", 3))),
+			query:       "CASE WHEN (`a` = ?) THEN ? ELSE `b` > ? END",
+			value:       []interface{}{1, 2, 3},
+		},
+		{
+			caseBuilder: Case(When(Eq("col", "a"), 1), When(Eq("col", "b"), 2), Else(3)),
+			query:       "CASE WHEN (`col` = ?) THEN ? WHEN (`col` = ?) THEN ? ELSE ? END",
+			value:       []interface{}{"a", 1, "b", 2, 3},
+		},
+		{
+			caseBuilder: Case(When(Eq("colA", "a"), Lt("colB", 5)), When(Eq("colA", "b"), Lt("colB", 10)), Else(Lt("colB", 15))),
+			query:       "CASE WHEN (`colA` = ?) THEN `colB` < ? WHEN (`colA` = ?) THEN `colB` < ? ELSE `colB` < ? END",
+			value:       []interface{}{"a", 5, "b", 10, 15},
+		},
+		{
+			caseBuilder: Case(When(Eq("colA", "a"), Lt("colB", 5)), When(Eq("colA", "b"), Lt("colB", 10)), Else(Lt("colB", 15))).As("c"),
+			query:       "CASE WHEN (`colA` = ?) THEN `colB` < ? WHEN (`colA` = ?) THEN `colB` < ? ELSE `colB` < ? END AS `c`",
+			value:       []interface{}{"a", 5, "b", 10, 15},
+		},
+	} {
+		buf := NewBuffer()
+		err := test.caseBuilder.Build(dialect.Clickhouse, buf)
+		require.NoError(t, err)
+		require.Equal(t, test.query, buf.String())
+		require.Equal(t, test.value, buf.Value())
+	}
+}

comments_test.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"testing"
 
-	"github.com/gocraft/dbr/v2/dialect"
 	"github.com/stretchr/testify/require"
 )
 
@@ -30,18 +29,8 @@ func TestComments(t *testing.T) {
 			expect:   "/* test nested comment removed */\n",
 		},
 	} {
-
 		for _, sess := range testSession {
-			name := ""
-			switch sess.Dialect {
-			case dialect.MySQL:
-				name = "MySQL"
-			case dialect.PostgreSQL:
-				name = "PostgreSQL"
-			case dialect.SQLite3:
-				name = "SQLite3"
-			}
-			t.Run(fmt.Sprintf("%s/%s", name, test.name), func(t *testing.T) {
+			t.Run(fmt.Sprintf("%s/%s", testSessionName(sess), test.name), func(t *testing.T) {
 				buf := NewBuffer()
 				err := test.comments.Build(sess.Dialect, buf)
 				require.NoError(t, err)

dbr.go

@@ -22,6 +22,8 @@ func Open(driver, dsn string, log EventReceiver) (*Connection, error) {
 	}
 	var d Dialect
 	switch driver {
+	case "clickhouse":
+		d = dialect.Clickhouse
 	case "mysql":
 		d = dialect.MySQL
 	case "postgres", "pgx":