Schema migration dry run or generate .sql file

[nghenglim]

Issue type:

[x ] question
[ ] bug report
[ x] feature request
[ ] documentation issue

Database system/driver:

[ ] cordova
[ ] mongodb
[ ] mssql
[ ] mysql / mariadb
[ ] oracle
[ x] postgres
[ ] sqlite
[ ] sqljs
[ ] react-native
[ ] expo

TypeORM version:

[ x] latest
[ ] @next
[ ] 0.x.x (or put your version here)

Steps to reproduce or a small repository showing the problem:

Typeorm migrations seems like missing the ability to dry run migrations to look on the sql generated for migrations. This feature is impremented on db-migrate.

It seems similar to the schema:log: Shows sql to be executed by schema:sync command. It shows sql log only for your default connection. To run update queries on a concrete connection use -c option.

[gintsgints]

How about you do typeorm migration:generate -n FoundChanges

[nghenglim]

@gintsgints that seems will generate the migration file in ts. In RDBMS (production), I will prefer not to give app permission to Create or drop table / indexes. Therefore generate it into .sql is preferred.

Besides, using the native syntax of query runner is not as good when we want to switch between mysql/postgres/mssql/nosql.

Imagination on how the dry run syntax can work:

1. there is two migration file named initial.ts and second.ts
2. run typeorm migration:dry-run --driver=postgres or typeorm migration:dry-run --env=production
3. generate file postgres/up/initial.sql and postgres/up/second.sql (throw error if driver is not supported)
4. the sql file generated will update the migration table on success

I might be able to spend some time working on this feature if the changes to the code base is small,

[qbright]

i have the same problem , so i develop a command tools to do this ，https://www.npmjs.com/package/typeorm-migrate-to-sql

hope can help you

[nghenglim]

@qbright nice one!

after one year from now start getting less usage on typeorm (due to the code structure not able to tree-shake well), I shall unsubscribe from this thread

[mwmw7]

We need to add dry run

[sarahhenkens]

@pleerock @holm: I don't think we should close this issue yet. I think having a dry-run option for typeorm migration:run is still very useful to have. PR #6978 is not implementing a dry-run option.

Something like the following could print out the queries that will be generated:

npm run typeorm migration:run --dry

It's especially useful when we use the built-in helper functions instead of manually writing SQL:

public async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.addColumn('episodes',  new TableColumn({
        name: "date_deleted",
        type: "datetime",
        isNullable: true,
        default: null,
    }));
}

For me personally, I just want to be able to print out the resulting queries that will be executed to stdout without doing a round-trip to the database. To do a quick sanity check if the resulting series of DDL operations look okay. Maybe it's better to always just write manual queries? 🤔

[DylanCulfogienis]

Any news on this? There is a dry run for migration:generate but we need one for migration:run

[bombillazo]

This feature is a must for CI/CD

[nodegin]

Is the --fake option works the same? I don't understand why it still inserts into migration table after run though.

[AlissonRS]

@nodegin the --fake__ option will simply pretend to run migrations, by inserting pending migrations from your code into the _migrations` table on your database, without actually running any of the migrations (won't create tables, modify schemas, etc).

It's not the same as a --dry option to just show the SQL script that would have been executed by a run command.