SQLMonkey.cs

using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SQLMonkey {
    class SQLMonkey {
        public string connectionString { get; set; }

        public SQLMonkey(string connectionString) {
            this.connectionString = connectionString;
        }

        private void executeScalarQuery(string sqlQuery) {
            using (var connection = new SqlConnection(connectionString)) {
                connection.Open();
                var command = new SqlCommand(sqlQuery, connection);
                command.ExecuteScalar();
            }
        }

        public void insert<T>(T instance, string tableName) {
            var sqlQuery = SQLGeneration.generateInsertQuery<T>(instance, tableName);
            executeScalarQuery(sqlQuery);
        }

        public void update<T>(T instance, string tableName) {
            var sqlQuery = SQLGeneration.generateUpdateQuery<T>(instance, tableName);
            executeScalarQuery(sqlQuery);
        }

        public void delete<T>(T instance, string tableName) {
            var sqlQuery = SQLGeneration.generateDeleteQuery<T>(instance, tableName);
            executeScalarQuery(sqlQuery);
        }

        public IEnumerable<T> retrieve<T>(string tableName) {
            var sqlQuery = SQLGeneration.generateRetrieveQuery(tableName);
            using (var connection = new SqlConnection(connectionString)) {
                connection.Open();
                var command = new SqlCommand(sqlQuery, connection);
                using (SqlDataReader reader = command.ExecuteReader()) {
                    while (reader.Read()) {
                        var instance = (T)Activator.CreateInstance(typeof(T));
                        var propValuePairs = instance.GetType().GetProperties().Select(x => x.Name);

                        foreach (var prop in propValuePairs) {
                            instance.GetType().GetProperty(prop).SetValue(instance, reader[prop], null);
                        }

                        yield return instance;
                    }
                }
            }
        }
    }
}