Implement SQL Server compatibility level

Closes dotnet#30163

Author: roji

Diff for: src/EFCore.SqlServer/Extensions/SqlServerServiceCollectionExtensions.cs

@@ -127,8 +127,10 @@ public static IServiceCollection AddEntityFrameworkSqlServer(this IServiceCollec
             .TryAdd<INavigationExpansionExtensibilityHelper, SqlServerNavigationExpansionExtensibilityHelper>()
             .TryAdd<IQueryableMethodTranslatingExpressionVisitorFactory, SqlServerQueryableMethodTranslatingExpressionVisitorFactory>()
             .TryAdd<IExceptionDetector, SqlServerExceptionDetector>()
+            .TryAdd<ISingletonOptions, ISqlServerSingletonOptions>(p => p.GetRequiredService<ISqlServerSingletonOptions>())
             .TryAddProviderSpecificServices(
                 b => b
+                    .TryAddSingleton<ISqlServerSingletonOptions, SqlServerSingletonOptions>()
                     .TryAddSingleton<ISqlServerValueGeneratorCache, SqlServerValueGeneratorCache>()
                     .TryAddSingleton<ISqlServerUpdateSqlGenerator, SqlServerUpdateSqlGenerator>()
                     .TryAddSingleton<ISqlServerSequenceValueGeneratorFactory, SqlServerSequenceValueGeneratorFactory>()

Diff for: src/EFCore.SqlServer/Infrastructure/Internal/ISqlServerSingletonOptions.cs

@@ -0,0 +1,29 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.EntityFrameworkCore.SqlServer.Infrastructure.Internal;
+
+/// <summary>
+///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+///     any release. You should only use it directly in your code with extreme caution and knowing that
+///     doing so can result in application failures when updating to a new Entity Framework Core release.
+/// </summary>
+public interface ISqlServerSingletonOptions : ISingletonOptions
+{
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    int CompatibilityLevel { get; }
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    int? CompatibilityLevelWithoutDefault { get; }
+}

Diff for: src/EFCore.SqlServer/Infrastructure/Internal/SqlServerOptionsExtension.cs

@@ -14,6 +14,21 @@ namespace Microsoft.EntityFrameworkCore.SqlServer.Infrastructure.Internal;
 public class SqlServerOptionsExtension : RelationalOptionsExtension
 {
     private DbContextOptionsExtensionInfo? _info;
+    private int? _compatibilityLevel;
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    // See https://learn.microsoft.com/sql/t-sql/statements/alter-database-transact-sql-compatibility-level
+    // SQL Server 2022 (16.x): compatibility level 160, start date 2022-11-16, mainstream end date 2028-01-11, extended end date 2033-01-11
+    // SQL Server 2019 (15.x): compatibility level 150, start date 2019-11-04, mainstream end date 2025-02-28, extended end date 2030-01-08
+    // SQL Server 2017 (14.x): compatibility level 140, start date 2017-09-29, mainstream end date 2022-10-11, extended end date 2027-10-12
+    // SQL Server 2016 (13.x): compatibility level 130, start date 2016-06-01, mainstream end date 2021-07-13, extended end date 2026-07-14
+    // SQL Server 2014 (12.x): compatibility level 120, start date 2014-06-05, mainstream end date 2019-07-09, extended end date 2024-07-09
+    private static readonly int DefaultCompatibilityLevel = 160;
 
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
@@ -36,6 +51,7 @@ public SqlServerOptionsExtension()
     protected SqlServerOptionsExtension(SqlServerOptionsExtension copyFrom)
         : base(copyFrom)
     {
+        _compatibilityLevel = copyFrom._compatibilityLevel;
     }
 
     /// <summary>
@@ -56,6 +72,39 @@ public override DbContextOptionsExtensionInfo Info
     protected override RelationalOptionsExtension Clone()
         => new SqlServerOptionsExtension(this);
 
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public virtual int CompatibilityLevel
+        => _compatibilityLevel ?? DefaultCompatibilityLevel;
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public virtual int? CompatibilityLevelWithoutDefault
+        => _compatibilityLevel;
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public virtual SqlServerOptionsExtension WithCompatibilityLevel(int? compatibilityLevel)
+    {
+        var clone = (SqlServerOptionsExtension)Clone();
+
+        clone._compatibilityLevel = compatibilityLevel;
+
+        return clone;
+    }
+
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
     ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
@@ -81,7 +130,8 @@ public override bool IsDatabaseProvider
             => true;
 
         public override bool ShouldUseSameServiceProvider(DbContextOptionsExtensionInfo other)
-            => other is ExtensionInfo;
+            => other is ExtensionInfo otherInfo
+                && Extension.CompatibilityLevel == otherInfo.Extension.CompatibilityLevel;
 
         public override string LogFragment
         {
@@ -93,6 +143,13 @@ public override string LogFragment
 
                     builder.Append(base.LogFragment);
 
+                    if (Extension._compatibilityLevel is int compatibilityLevel)
+                    {
+                        builder
+                            .Append("CompatibilityLevel=")
+                            .Append(compatibilityLevel);
+                    }
+
                     _logFragment = builder.ToString();
                 }
 
@@ -101,6 +158,13 @@ public override string LogFragment
         }
 
         public override void PopulateDebugInfo(IDictionary<string, string> debugInfo)
-            => debugInfo["SqlServer"] = "1";
+        {
+            debugInfo["SqlServer"] = "1";
+
+            if (Extension.CompatibilityLevel is int compatibilityLevel)
+            {
+                debugInfo["CompatibilityLevel"] = compatibilityLevel.ToString();
+            }
+        }
     }
 }

Diff for: src/EFCore.SqlServer/Infrastructure/Internal/SqlServerSingletonOptions.cs

@@ -0,0 +1,66 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.EntityFrameworkCore.SqlServer.Infrastructure.Internal;
+
+/// <summary>
+///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+///     any release. You should only use it directly in your code with extreme caution and knowing that
+///     doing so can result in application failures when updating to a new Entity Framework Core release.
+/// </summary>
+public class SqlServerSingletonOptions : ISqlServerSingletonOptions
+{
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public virtual int CompatibilityLevel { get; private set; }
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public virtual int? CompatibilityLevelWithoutDefault { get; private set; }
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public virtual void Initialize(IDbContextOptions options)
+    {
+        var sqlServerOptions = options.FindExtension<SqlServerOptionsExtension>();
+        if (sqlServerOptions != null)
+        {
+            CompatibilityLevel = sqlServerOptions.CompatibilityLevel;
+            CompatibilityLevelWithoutDefault = sqlServerOptions.CompatibilityLevelWithoutDefault;
+        }
+    }
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public virtual void Validate(IDbContextOptions options)
+    {
+        var sqlserverOptions = options.FindExtension<SqlServerOptionsExtension>();
+
+        if (sqlserverOptions != null &&
+            (CompatibilityLevelWithoutDefault != sqlserverOptions.CompatibilityLevelWithoutDefault
+            || CompatibilityLevel != sqlserverOptions.CompatibilityLevel))
+        {
+            throw new InvalidOperationException(
+                CoreStrings.SingletonOptionChanged(
+                    nameof(SqlServerDbContextOptionsExtensions.UseSqlServer),
+                    nameof(DbContextOptionsBuilder.UseInternalServiceProvider)));
+        }
+    }
+}

Diff for: src/EFCore.SqlServer/Infrastructure/SqlServerDbContextOptionsBuilder.cs

@@ -103,4 +103,18 @@ public virtual SqlServerDbContextOptionsBuilder EnableRetryOnFailure(
         TimeSpan maxRetryDelay,
         IEnumerable<int>? errorNumbersToAdd)
         => ExecutionStrategy(c => new SqlServerRetryingExecutionStrategy(c, maxRetryCount, maxRetryDelay, errorNumbersToAdd));
+
+    /// <summary>
+    ///     Sets the SQL Server compatibility level that EF Core will use when interacting with the database. This allows configuring EF
+    ///     Core to work with older (or newer) versions of SQL Server. Defaults to <c>150</c> (SQL Server 2019).
+    /// </summary>
+    /// <remarks>
+    ///     See <see href="https://aka.ms/efcore-docs-dbcontext-options">Using DbContextOptions</see>, and
+    ///     <see href="https://learn.microsoft.com/sql/t-sql/statements/alter-database-transact-sql-compatibility-level">SQL Server
+    ///     documentation on compatibility level</see> for more information and examples.
+    /// </remarks>
+    /// <param name="compatibilityLevel"><see langword="false" /> to have null resource</param>
+    // TODO: Naming; Cosmos doesn't have Use/Set, so just CompatibilityLevel? SetCompatibilityLevel?
+    public virtual SqlServerDbContextOptionsBuilder UseCompatibilityLevel(int compatibilityLevel)
+        => WithOption(e => e.WithCompatibilityLevel(compatibilityLevel));
 }