From 8b716c34a40e4947bd135d1fa4a1e671f250284f Mon Sep 17 00:00:00 2001
From: Shay Rojansky <roji@roji.org>
Date: Sat, 2 Jul 2022 10:12:37 +0200
Subject: [PATCH] Fix dropping of sequence and dependent column

Fixes #28349
---
 .../Internal/MigrationsModelDiffer.cs         |  7 ++-
 .../Migrations/MigrationsSqlServerTest.cs     | 48 +++++++++++++++++++
 .../Migrations/SqlServerModelDifferTest.cs    | 12 ++---
 3 files changed, 60 insertions(+), 7 deletions(-)

diff --git a/src/EFCore.Relational/Migrations/Internal/MigrationsModelDiffer.cs b/src/EFCore.Relational/Migrations/Internal/MigrationsModelDiffer.cs
index 07dc3e9d6b8..41a6029ba1a 100644
--- a/src/EFCore.Relational/Migrations/Internal/MigrationsModelDiffer.cs
+++ b/src/EFCore.Relational/Migrations/Internal/MigrationsModelDiffer.cs
@@ -20,7 +20,6 @@ public class MigrationsModelDiffer : IMigrationsModelDiffer
     {
         typeof(DropIndexOperation),
         typeof(DropPrimaryKeyOperation),
-        typeof(DropSequenceOperation),
         typeof(DropUniqueConstraintOperation),
         typeof(DropCheckConstraintOperation)
     };
@@ -131,6 +130,7 @@ protected virtual IReadOnlyList<MigrationOperation> Sort(
         var dropColumnOperations = new List<MigrationOperation>();
         var dropComputedColumnOperations = new List<MigrationOperation>();
         var dropTableOperations = new List<DropTableOperation>();
+        var dropSequenceOperations = new List<MigrationOperation>();
         var ensureSchemaOperations = new List<MigrationOperation>();
         var createSequenceOperations = new List<MigrationOperation>();
         var createTableOperations = new List<CreateTableOperation>();
@@ -173,6 +173,10 @@ protected virtual IReadOnlyList<MigrationOperation> Sort(
             {
                 dropTableOperations.Add((DropTableOperation)operation);
             }
+            else if (type == typeof(DropSequenceOperation))
+            {
+                dropSequenceOperations.Add((DropSequenceOperation)operation);
+            }
             else if (type == typeof(EnsureSchemaOperation))
             {
                 ensureSchemaOperations.Add(operation);
@@ -312,6 +316,7 @@ protected virtual IReadOnlyList<MigrationOperation> Sort(
             .Concat(sourceDataOperations)
             .Concat(dropComputedColumnOperations)
             .Concat(dropColumnOperations)
+            .Concat(dropSequenceOperations)
             .Concat(ensureSchemaOperations)
             .Concat(renameTableOperations)
             .Concat(renameOperations)
diff --git a/test/EFCore.SqlServer.FunctionalTests/Migrations/MigrationsSqlServerTest.cs b/test/EFCore.SqlServer.FunctionalTests/Migrations/MigrationsSqlServerTest.cs
index 5038a79aa12..c5f29cab1e3 100644
--- a/test/EFCore.SqlServer.FunctionalTests/Migrations/MigrationsSqlServerTest.cs
+++ b/test/EFCore.SqlServer.FunctionalTests/Migrations/MigrationsSqlServerTest.cs
@@ -2286,6 +2286,54 @@ await Test(
 EXEC(N'ALTER SCHEMA [' + @defaultSchema + N'] TRANSFER [TestSequenceSchema].[TestSequence];');");
     }
 
+    [ConditionalFact]
+    public async Task Create_sequence_and_dependent_column()
+    {
+        await Test(
+            builder => builder.Entity("People").Property<int>("Id"),
+            builder => { },
+            builder =>
+            {
+                builder.HasSequence<int>("TestSequence");
+                builder.Entity("People").Property<int>("SeqProp").HasDefaultValueSql("NEXT VALUE FOR TestSequence");
+            },
+            model =>
+            {
+                var sequence = Assert.Single(model.Sequences);
+                Assert.Equal("TestSequence", sequence.Name);
+            });
+
+        AssertSql(
+            @"CREATE SEQUENCE [TestSequence] AS int START WITH 1 INCREMENT BY 1 NO MINVALUE NO MAXVALUE NO CYCLE;",
+            //
+            @"ALTER TABLE [People] ADD [SeqProp] int NOT NULL DEFAULT (NEXT VALUE FOR TestSequence);");
+    }
+
+    [ConditionalFact]
+    public async Task Drop_sequence_and_dependent_column()
+    {
+        await Test(
+            builder => builder.Entity("People").Property<int>("Id"),
+            builder =>
+            {
+                builder.HasSequence<int>("TestSequence");
+                builder.Entity("People").Property<int>("SeqProp").HasDefaultValueSql("NEXT VALUE FOR TestSequence");
+            },
+            builder => { },
+            model => Assert.Empty(model.Sequences));
+
+        AssertSql(
+            @"DECLARE @var0 sysname;
+SELECT @var0 = [d].[name]
+FROM [sys].[default_constraints] [d]
+INNER JOIN [sys].[columns] [c] ON [d].[parent_column_id] = [c].[column_id] AND [d].[parent_object_id] = [c].[object_id]
+WHERE ([d].[parent_object_id] = OBJECT_ID(N'[People]') AND [c].[name] = N'SeqProp');
+IF @var0 IS NOT NULL EXEC(N'ALTER TABLE [People] DROP CONSTRAINT [' + @var0 + '];');
+ALTER TABLE [People] DROP COLUMN [SeqProp];",
+            //
+            @"DROP SEQUENCE [TestSequence];");
+    }
+
     public override async Task InsertDataOperation()
     {
         await base.InsertDataOperation();
diff --git a/test/EFCore.SqlServer.Tests/Migrations/SqlServerModelDifferTest.cs b/test/EFCore.SqlServer.Tests/Migrations/SqlServerModelDifferTest.cs
index 4e6b9c50b77..cabe31d8f96 100644
--- a/test/EFCore.SqlServer.Tests/Migrations/SqlServerModelDifferTest.cs
+++ b/test/EFCore.SqlServer.Tests/Migrations/SqlServerModelDifferTest.cs
@@ -420,17 +420,17 @@ public void Add_SequenceHiLo_with_seed_data()
             downOps => Assert.Collection(
                 downOps,
                 o =>
-                {
-                    var operation = Assert.IsType<DropSequenceOperation>(o);
-                    Assert.Equal("dbo", operation.Schema);
-                    Assert.Equal("EntityFrameworkHiLoSequence", operation.Name);
-                },
-                o =>
                 {
                     var m = Assert.IsType<DeleteDataOperation>(o);
                     AssertMultidimensionalArray(
                         m.KeyValues,
                         v => Assert.Equal(43, v));
+                },
+                o =>
+                {
+                    var operation = Assert.IsType<DropSequenceOperation>(o);
+                    Assert.Equal("dbo", operation.Schema);
+                    Assert.Equal("EntityFrameworkHiLoSequence", operation.Name);
                 }));
 
     [ConditionalFact]