Kysely•2mo ago

Transaction is necessary in the migration file?

Hi May I know if we need to wrap the migration in a transaction like the following?

export async function up(db: Kysely<any>): Promise<void> {
  await db.transaction().execute(async (trx) => {
    await db.schema.createTable(...)
  })
  ...
}

export async function down(db: Kysely<any>): Promise<void> {
  await db.transaction().execute(async (trx) => {
    await db.schema.dropTable(...)
  })
  ...
}

export async function up(db: Kysely<any>): Promise<void> {
  await db.transaction().execute(async (trx) => {
    await db.schema.createTable(...)
  })
  ...
}

export async function down(db: Kysely<any>): Promise<void> {
  await db.transaction().execute(async (trx) => {
    await db.schema.dropTable(...)
  })
  ...
}

or this is taken care by the migrator?

4 Replies

Igal (mobile)•2mo ago

Hey 👋 Taken care of in the migrator, if you're using a database that supports transactional DDL.

tj1892OP•2mo ago

@Igal (mobile) Uh ... it looks like MySQL 8 is not supporting transactional DDL, and I will have to add the transaction in the migration file. Thanks to point out this and this could be useful to mention in https://kysely.dev/docs/migrations too See also https://www.bytebase.com/blog/postgres-vs-mysql-ddl-transaction/

Migrations | Kysely

Migration files

Bytebase

Postgres vs. MySQL: DDL Transaction Difference

Database schema changes are critical operations that require careful planning and execution. The ability to perform these changes safely and reliably is a key c...

Igal (mobile)•2mo ago

It won't help you. MySQL doesnt support transactional DDL. The trandaction will commit prematurely after the first DDL query you run with it.

tj1892OP•2mo ago

You're right, I'm seeing the issue now.

Gaming

Programming

Transaction is necessary in the migration file?

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