Proper [NOT] NULL handling for altering columns in migrations (#977).

Author: cincuranet

Provider/src/FirebirdSql.EntityFrameworkCore.Firebird.Tests/Migrations/MigrationsTests.cs

@@ -326,9 +326,10 @@ public async Task AlterColumnNullableToNotNull()
 				},
 			};
 			var batch = await Generate(new[] { operation });
-			Assert.AreEqual(2, batch.Count());
+			Assert.AreEqual(3, batch.Count());
 			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" DROP NOT NULL;"), batch[0].CommandText);
-			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE VARCHAR(100) NOT NULL;"), batch[1].CommandText);
+			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE VARCHAR(100);"), batch[1].CommandText);
+			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" SET NOT NULL;"), batch[2].CommandText);
 		}
 
 		[Test]
@@ -370,8 +371,8 @@ public async Task AlterColumnType()
 				},
 			};
 			var batch = await Generate(new[] { operation });
-			Assert.AreEqual(2, batch.Count());
-			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE BIGINT NOT NULL;"), batch[1].CommandText);
+			Assert.AreEqual(3, batch.Count());
+			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE BIGINT;"), batch[1].CommandText);
 		}
 
 		[Test]
@@ -390,10 +391,10 @@ public async Task AlterColumnDefault()
 				},
 			};
 			var batch = await Generate(new[] { operation });
-			Assert.AreEqual(4, batch.Count());
-			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE INTEGER NOT NULL;"), batch[1].CommandText);
-			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" DROP DEFAULT;"), batch[2].CommandText);
-			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" SET DEFAULT 20;"), batch[3].CommandText);
+			Assert.AreEqual(5, batch.Count());
+			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE INTEGER;"), batch[1].CommandText);
+			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" DROP DEFAULT;"), batch[3].CommandText);
+			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" SET DEFAULT 20;"), batch[4].CommandText);
 		}
 
 		[Test]
@@ -411,8 +412,8 @@ public async Task AlterColumnAddIdentityColumn()
 				},
 			};
 			var batch = await Generate(new[] { operation });
-			Assert.AreEqual(2, batch.Count());
-			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE INTEGER GENERATED BY DEFAULT AS IDENTITY NOT NULL;"), batch[1].CommandText);
+			Assert.AreEqual(3, batch.Count());
+			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE INTEGER GENERATED BY DEFAULT AS IDENTITY;"), batch[1].CommandText);
 		}
 
 		[Test]
@@ -430,10 +431,10 @@ public async Task AlterColumnAddSequenceTrigger()
 				},
 			};
 			var batch = await Generate(new[] { operation });
-			Assert.AreEqual(4, batch.Count());
-			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE INTEGER NOT NULL;"), batch[1].CommandText);
-			StringAssert.Contains("rdb$generator_name = ", batch[2].CommandText);
-			StringAssert.StartsWith("CREATE TRIGGER ", batch[3].CommandText);
+			Assert.AreEqual(5, batch.Count());
+			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE INTEGER;"), batch[1].CommandText);
+			StringAssert.Contains("rdb$generator_name = ", batch[3].CommandText);
+			StringAssert.StartsWith("CREATE TRIGGER ", batch[4].CommandText);
 		}
 
 		[Test]
@@ -451,9 +452,9 @@ public async Task AlterColumnRemoveSequenceTrigger()
 				},
 			};
 			var batch = await Generate(new[] { operation });
-			Assert.AreEqual(3, batch.Count());
+			Assert.AreEqual(4, batch.Count());
 			StringAssert.Contains("drop trigger", batch[0].CommandText);
-			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE INTEGER NOT NULL;"), batch[2].CommandText);
+			Assert.AreEqual(NewLineEnd(@"ALTER TABLE ""People"" ALTER COLUMN ""Col"" TYPE INTEGER;"), batch[2].CommandText);
 		}
 
 		[Test]

Provider/src/FirebirdSql.EntityFrameworkCore.Firebird/Migrations/FbMigrationsSqlGenerator.cs

@@ -131,9 +131,18 @@ protected override void Generate(AlterColumnOperation operation, IModel model, M
 			{
 				builder.Append(" GENERATED BY DEFAULT AS IDENTITY");
 			}
-			builder.Append(operation.IsNullable ? string.Empty : " NOT NULL");
 			TerminateStatement(builder);
 
+			if (!operation.IsNullable)
+			{
+				builder.Append("ALTER TABLE ");
+				builder.Append(Dependencies.SqlGenerationHelper.DelimitIdentifier(operation.Table, operation.Schema));
+				builder.Append(" ALTER COLUMN ");
+				builder.Append(Dependencies.SqlGenerationHelper.DelimitIdentifier(operation.Name));
+				builder.Append(" SET NOT NULL");
+				TerminateStatement(builder);
+			}
+
 			if (operation.DefaultValue != null || !string.IsNullOrWhiteSpace(operation.DefaultValueSql))
 			{
 				builder.Append("ALTER TABLE ");