addColumn in migration does not work as expected

Issue type:

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

Database system/driver:

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

TypeORM version:

[ ] latest [ ] @next [x] 0.2.8

I have a migration to add a new column to an existing table (with data in it) using the following code:

async up(queryRunner: QueryRunner): Promise<any> {
    await queryRunner.addColumn('myTable', new TableColumn({
        name: 'my_new_column_name',
        type: 'varchar',
        isNullable: true
    });
}

My expectation was that this code would be transformed to an ALTER TABLE query in the background. When logging all database activity, I saw it actually tried to create a temporary table and drop the actual table. This seems weird to me and it also gave me an error because there was already a foreign key constraint on another column in this table. So the migration didn’t work. I fixed it by manually putting in an ALTER TABLE query, but shouldn’t addColumn already do that?

[andrewdhazlett]

I was able to fix a similar issue (on postgres) by wrapping my default value in single quotes:

Previously I was getting the error column "open" does not exist:

This is downright baffling behavior.

[WimWidgets]

@lili21 As I said in the last line: I fixed it by manually putting in an ALTER TABLE query, […]

So not a real structural fix, but at least I got it working.

await queryRunner.query(`ALTER TABLE "myTable" ADD COLUMN "my_new_column_name" VARCHAR(255) DEFAULT NULL`);