fix(schema): respect length of default value of datetime columns

Closes #4782

packages/knex/src/schema/DatabaseTable.ts

@@ -75,14 +75,20 @@ export class DatabaseTable {
 
         /* istanbul ignore else */
         if (match) {
-          prop.precision = +match[1];
-          prop.scale = +match[2];
+          prop.precision ??= +match[1];
+          prop.scale ??= +match[2];
           prop.length = undefined;
         }
       }
 
       if (mappedType instanceof DateTimeType) {
-        prop.length ??= this.platform.getDefaultDateTimeLength();
+        const match = prop.columnTypes[idx].match(/\w+\((\d+)\)/);
+
+        if (match) {
+          prop.length ??= +match[1];
+        } else {
+          prop.length ??= this.platform.getDefaultDateTimeLength();
+        }
       }
 
       const primary = !meta.compositePK && !!prop.primary && prop.reference === ReferenceType.SCALAR && this.platform.isNumericColumn(mappedType);

tests/features/schema-generator/GH4782.test.ts

@@ -0,0 +1,91 @@
+import { MikroORM } from '@mikro-orm/mysql';
+import { Entity, PrimaryKey, Property, t } from '@mikro-orm/core';
+
+@Entity({ tableName: 'user' })
+class User0 {
+
+  @PrimaryKey()
+  id!: number;
+
+}
+
+@Entity({ tableName: 'user' })
+class User1 {
+
+  @PrimaryKey()
+  id!: number;
+
+  @Property({ defaultRaw: 'current_timestamp(3)', columnType: 'timestamp(3)' })
+  bar!: Date;
+
+}
+
+@Entity({ tableName: 'user' })
+class User2 {
+
+  @PrimaryKey()
+  id!: number;
+
+  @Property({ defaultRaw: 'current_timestamp(3)', columnType: 'timestamp(3)' })
+  bar!: Date;
+
+}
+
+@Entity({ tableName: 'user' })
+class User3 {
+
+  @PrimaryKey()
+  id!: number;
+
+  @Property({ defaultRaw: 'current_timestamp(6)', columnType: 'timestamp(6)' })
+  bar!: Date;
+
+}
+
+@Entity({ tableName: 'user' })
+class User4 {
+
+  @PrimaryKey()
+  id!: number;
+
+}
+
+let orm: MikroORM;
+
+beforeAll(async () => {
+  orm = await MikroORM.init({
+    entities: [User0],
+    dbName: 'mikro_orm_test_gh_4782',
+    port: 3308,
+  });
+  await orm.schema.ensureDatabase();
+  await orm.schema.dropSchema();
+});
+
+afterAll(() => orm.close(true));
+
+test('4782', async () => {
+  const testMigration = async (e1: any, e2: any, snap: string) => {
+    if (e2) {
+      orm.getMetadata().reset(e1.name);
+      await orm.discoverEntity(e2);
+    }
+
+    const diff = await orm.schema.getUpdateSchemaMigrationSQL({ wrap: false });
+    expect(diff).toMatchSnapshot(snap);
+    await orm.schema.execute(diff.up);
+
+    return diff.down;
+  };
+
+  const down: string[] = [];
+  down.push(await testMigration(User0, undefined, '0. create schema'));
+  down.push(await testMigration(User0, User1, '1. add timestamp(3) column'));
+  down.push(await testMigration(User1, User2, '2. no changes'));
+  down.push(await testMigration(User2, User3, '3. change to timestamp(6)'));
+  down.push(await testMigration(User3, User4, '4. remove timestamp column'));
+
+  for (const sql of down.reverse()) {
+    await orm.schema.execute(sql);
+  }
+});

tests/features/schema-generator/__snapshots__/GH4782.test.ts.snap

@@ -0,0 +1,52 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`4782: 0. create schema 1`] = `
+{
+  "down": "drop table if exists \`user\`;
+
+",
+  "up": "create table \`user\` (\`id\` int unsigned not null auto_increment primary key) default character set utf8mb4 engine = InnoDB;
+
+",
+}
+`;
+
+exports[`4782: 1. add timestamp(3) column 1`] = `
+{
+  "down": "alter table \`user\` drop \`bar\`;
+
+",
+  "up": "alter table \`user\` add \`bar\` timestamp(3) not null default current_timestamp(3);
+
+",
+}
+`;
+
+exports[`4782: 2. no changes 1`] = `
+{
+  "down": "",
+  "up": "",
+}
+`;
+
+exports[`4782: 3. change to timestamp(6) 1`] = `
+{
+  "down": "alter table \`user\` modify \`bar\` timestamp(3) not null default current_timestamp(3);
+
+",
+  "up": "alter table \`user\` modify \`bar\` timestamp(6) not null default current_timestamp(6);
+
+",
+}
+`;
+
+exports[`4782: 4. remove timestamp column 1`] = `
+{
+  "down": "alter table \`user\` add \`bar\` timestamp(6) not null default current_timestamp(6);
+
+",
+  "up": "alter table \`user\` drop \`bar\`;
+
+",
+}
+`;