SqlServer Migrations: Add EXEC calls to idempotent script

Also adds the ability for providers to detected whether a script is being generated and whether its idempotent. (resolves #14746)

Fixes #12911

src/EFCore.Design/Design/Internal/MigrationsOperations.cs

@@ -165,7 +165,7 @@ public virtual IEnumerable<MigrationInfo> GetMigrations(
         public virtual string ScriptMigration(
             [CanBeNull] string fromMigration,
             [CanBeNull] string toMigration,
-            bool idempotent,
+            MigrationsSqlGenerationOptions options,
             [CanBeNull] string contextType)
         {
             using var context = _contextOperations.CreateContext(contextType);
@@ -174,7 +174,7 @@ public virtual string ScriptMigration(
 
             var migrator = services.GetRequiredService<IMigrator>();
 
-            return migrator.GenerateScript(fromMigration, toMigration, idempotent);
+            return migrator.GenerateScript(fromMigration, toMigration, options);
         }
 
         /// <summary>

src/EFCore.Design/Design/OperationExecutor.cs

@@ -297,11 +297,19 @@ private string ScriptMigrationImpl(
             [CanBeNull] string toMigration,
             bool idempotent,
             [CanBeNull] string contextType)
-            => MigrationsOperations.ScriptMigration(
+        {
+            var options = MigrationsSqlGenerationOptions.Default;
+            if (idempotent)
+            {
+                options |= MigrationsSqlGenerationOptions.Idempotent;
+            }
+
+            return MigrationsOperations.ScriptMigration(
                 fromMigration,
                 toMigration,
-                idempotent,
+                options,
                 contextType);
+        }
 
         /// <summary>
         ///     Represents an operation to remove the last migration.

src/EFCore.Relational/Migrations/IMigrationsSqlGenerator.cs

@@ -28,9 +28,11 @@ public interface IMigrationsSqlGenerator
         /// </summary>
         /// <param name="operations"> The operations. </param>
         /// <param name="model"> The target model which may be <see langword="null" /> if the operations exist without a model. </param>
+        /// <param name="options"> The options to use when generating commands. </param>
         /// <returns> The list of commands to be executed or scripted. </returns>
         IReadOnlyList<MigrationCommand> Generate(
             [NotNull] IReadOnlyList<MigrationOperation> operations,
-            [CanBeNull] IModel model = null);
+            [CanBeNull] IModel model = null,
+            MigrationsSqlGenerationOptions options = MigrationsSqlGenerationOptions.Default);
     }
 }

src/EFCore.Relational/Migrations/IMigrator.cs

@@ -54,12 +54,10 @@ Task MigrateAsync(
         /// <param name="toMigration">
         ///     The target migration to migrate the database to, or <see langword="null" /> to migrate to the latest.
         /// </param>
-        /// <param name="idempotent">
-        ///     If <see langword="true" />, then idempotent scripts will be generated, otherwise
-        ///     scripts will be generated that assume none of the migrations in the range specified have
-        ///     already been applied to the database.
+        /// <param name="options">
+        ///     The options to use when generating SQL for migrations.
         /// </param>
         /// <returns> The generated script. </returns>
-        string GenerateScript([CanBeNull] string fromMigration = null, [CanBeNull] string toMigration = null, bool idempotent = false);
+        string GenerateScript([CanBeNull] string fromMigration = null, [CanBeNull] string toMigration = null, MigrationsSqlGenerationOptions options = MigrationsSqlGenerationOptions.Default);
     }
 }

src/EFCore.Relational/Migrations/Internal/Migrator.cs

@@ -303,8 +303,12 @@ protected virtual void PopulateMigrations(
         public virtual string GenerateScript(
             string fromMigration = null,
             string toMigration = null,
-            bool idempotent = false)
+            MigrationsSqlGenerationOptions options = MigrationsSqlGenerationOptions.Default)
         {
+            options |= MigrationsSqlGenerationOptions.Script;
+
+            var idempotent = options.HasFlag(MigrationsSqlGenerationOptions.Idempotent);
+
             IEnumerable<string> appliedMigrations;
             if (string.IsNullOrEmpty(fromMigration)
                 || fromMigration == Migration.InitialDatabase)
@@ -344,7 +348,7 @@ public virtual string GenerateScript(
 
                 _logger.MigrationGeneratingDownScript(this, migration, fromMigration, toMigration, idempotent);
 
-                foreach (var command in GenerateDownSql(migration, previousMigration))
+                foreach (var command in GenerateDownSql(migration, previousMigration, options))
                 {
                     if (idempotent)
                     {
@@ -369,7 +373,7 @@ public virtual string GenerateScript(
             {
                 _logger.MigrationGeneratingUpScript(this, migration, fromMigration, toMigration, idempotent);
 
-                foreach (var command in GenerateUpSql(migration))
+                foreach (var command in GenerateUpSql(migration, options))
                 {
                     if (idempotent)
                     {
@@ -399,15 +403,16 @@ public virtual string GenerateScript(
         ///     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>
-        protected virtual IReadOnlyList<MigrationCommand> GenerateUpSql([NotNull] Migration migration)
+        protected virtual IReadOnlyList<MigrationCommand> GenerateUpSql([NotNull] Migration migration,
+            MigrationsSqlGenerationOptions options = MigrationsSqlGenerationOptions.Default)
         {
             Check.NotNull(migration, nameof(migration));
 
             var insertCommand = _rawSqlCommandBuilder.Build(
                 _historyRepository.GetInsertScript(new HistoryRow(migration.GetId(), ProductInfo.GetVersion())));
 
             return _migrationsSqlGenerator
-                .Generate(migration.UpOperations, FinalizeModel(migration.TargetModel))
+                .Generate(migration.UpOperations, FinalizeModel(migration.TargetModel), options)
                 .Concat(new[] { new MigrationCommand(insertCommand, _currentContext.Context, _commandLogger) })
                 .ToList();
         }
@@ -420,15 +425,16 @@ protected virtual IReadOnlyList<MigrationCommand> GenerateUpSql([NotNull] Migrat
         /// </summary>
         protected virtual IReadOnlyList<MigrationCommand> GenerateDownSql(
             [NotNull] Migration migration,
-            [CanBeNull] Migration previousMigration)
+            [CanBeNull] Migration previousMigration,
+            MigrationsSqlGenerationOptions options = MigrationsSqlGenerationOptions.Default)
         {
             Check.NotNull(migration, nameof(migration));
 
             var deleteCommand = _rawSqlCommandBuilder.Build(
                 _historyRepository.GetDeleteScript(migration.GetId()));
 
             return _migrationsSqlGenerator
-                .Generate(migration.DownOperations, FinalizeModel(previousMigration?.TargetModel))
+                .Generate(migration.DownOperations, FinalizeModel(previousMigration?.TargetModel), options)
                 .Concat(new[] { new MigrationCommand(deleteCommand, _currentContext.Context, _commandLogger) })
                 .ToList();
         }

src/EFCore.Relational/Migrations/MigrationsSqlGenerationOptions.cs

@@ -0,0 +1,29 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+
+namespace Microsoft.EntityFrameworkCore.Migrations
+{
+    /// <summary>
+    ///     The options to use when generating SQL for migrations.
+    /// </summary>
+    [Flags]
+    public enum MigrationsSqlGenerationOptions
+    {
+        /// <summary>
+        ///     Generate SQL to execute at runtime.
+        /// </summary>
+        Default,
+
+        /// <summary>
+        ///     Generate SQL for a script. Automatically added by <see cref="IMigrator.GenerateScript" />.
+        /// </summary>
+        Script,
+
+        /// <summary>
+        ///     Generate SQL for an idempotent script.
+        /// </summary>
+        Idempotent
+    }
+}

src/EFCore.Relational/Migrations/MigrationsSqlGenerator.cs

@@ -107,22 +107,38 @@ protected virtual IUpdateSqlGenerator SqlGenerator
         /// </summary>
         protected virtual IComparer<string> VersionComparer { get; } = new SemanticVersionComparer();
 
+        /// <summary>
+        ///     Gets or sets the options to use when generating commands.
+        /// </summary>
+        protected virtual MigrationsSqlGenerationOptions Options { get; set; }
+
         /// <summary>
         ///     Generates commands from a list of operations.
         /// </summary>
         /// <param name="operations"> The operations. </param>
         /// <param name="model"> The target model which may be <see langword="null" /> if the operations exist without a model. </param>
+        /// <param name="options"> The options to use when generating commands. </param>
         /// <returns> The list of commands to be executed or scripted. </returns>
         public virtual IReadOnlyList<MigrationCommand> Generate(
             IReadOnlyList<MigrationOperation> operations,
-            IModel model = null)
+            IModel model = null,
+            MigrationsSqlGenerationOptions options = MigrationsSqlGenerationOptions.Default)
         {
             Check.NotNull(operations, nameof(operations));
 
+            Options = options;
+
             var builder = new MigrationCommandListBuilder(Dependencies);
-            foreach (var operation in operations)
+            try
+            {
+                foreach (var operation in operations)
+                {
+                    Generate(operation, model, builder);
+                }
+            }
+            finally
             {
-                Generate(operation, model, builder);
+                Options = MigrationsSqlGenerationOptions.Default;
             }
 
             return builder.GetCommandList();

src/EFCore.Relational/Storage/RelationalDatabaseCreator.cs

@@ -137,10 +137,11 @@ public virtual Task CreateTablesAsync(CancellationToken cancellationToken = defa
         /// <summary>
         ///     Gets the commands that will create all tables from the model.
         /// </summary>
+        /// <param name="options"> The options to use when generating commands. </param>
         /// <returns> The generated commands. </returns>
-        protected virtual IReadOnlyList<MigrationCommand> GetCreateTablesCommands()
+        protected virtual IReadOnlyList<MigrationCommand> GetCreateTablesCommands(MigrationsSqlGenerationOptions options = MigrationsSqlGenerationOptions.Default)
             => Dependencies.MigrationsSqlGenerator.Generate(
-                Dependencies.ModelDiffer.GetDifferences(null, Dependencies.Model.GetRelationalModel()), Dependencies.Model);
+                Dependencies.ModelDiffer.GetDifferences(null, Dependencies.Model.GetRelationalModel()), Dependencies.Model, options);
 
         /// <summary>
         ///     Determines whether the database contains any tables. No attempt is made to determine if
@@ -291,7 +292,7 @@ public virtual async Task<bool> EnsureCreatedAsync(CancellationToken cancellatio
         /// </returns>
         public virtual string GenerateCreateScript()
         {
-            var commands = GetCreateTablesCommands();
+            var commands = GetCreateTablesCommands(MigrationsSqlGenerationOptions.Script);
             var builder = new StringBuilder();
             foreach (var command in commands)
             {