Make PostgreSQL foreign key drops idempotent

changelogs/drizzle-kit/0.32.3.md

@@ -0,0 +1,3 @@
+### PostgreSQL bug fix
+
+Foreign-key removals now use `DROP CONSTRAINT IF EXISTS`. This prevents generated migrations from failing when an earlier `DROP TABLE ... CASCADE` already removed the same constraint.

drizzle-kit/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@drizzle-team/drizzle-kit",
-	"version": "0.32.1",
+	"version": "0.32.3",
 	"homepage": "https://orm.drizzle.team",
 	"keywords": [
 		"drizzle",

drizzle-kit/src/sqlgenerator.ts

@@ -3476,7 +3476,7 @@ class PgDeleteForeignKeyConvertor extends Convertor {
 			? `"${statement.schema}"."${tableFrom}"`
 			: `"${tableFrom}"`;
 
-		return `ALTER TABLE ${tableNameWithSchema} DROP CONSTRAINT "${name}";\n`;
+		return `ALTER TABLE ${tableNameWithSchema} DROP CONSTRAINT IF EXISTS "${name}";\n`;
 	}
 }
 

drizzle-kit/tests/pg-tables.test.ts

@@ -753,6 +753,28 @@ test('alter composite primary key', async () => {
 	]);
 });
 
+test('drop foreign key constraint idempotently', async () => {
+	const users = pgTable('users', {
+		id: integer('id').primaryKey(),
+	});
+	const postsFrom = pgTable('posts', {
+		userId: integer('user_id').references(() => users.id),
+	});
+	const postsTo = pgTable('posts', {
+		userId: integer('user_id'),
+	});
+
+	const { sqlStatements } = await diffTestSchemas(
+		{ users, posts: postsFrom },
+		{ users, posts: postsTo },
+		[],
+	);
+
+	expect(sqlStatements).toStrictEqual([
+		'ALTER TABLE "posts" DROP CONSTRAINT IF EXISTS "posts_user_id_users_id_fk";\n',
+	]);
+});
+
 test('add index with op', async () => {
 	const from = {
 		users: pgTable('users', {