Flutter SQFLite create multiple tables at once

Question

I'm using the code below and want to know how this database function can be altered so that it creates two separate tables at once:

  static Future<Database> database() async {
    final dbPath = await sql.getDatabasesPath();
    return sql.openDatabase(path.join(dbPath, 'mydatabase.db'), onCreate: (db, version) {
      return db.execute('CREATE TABLE mytable(date TEXT PRIMARY KEY, value DOUBLE)');
    }, version: 1);
  }

by calling: `await db.execute(...); await db.execute(...);` ? — pskink, Nov 03 '19 at 10:48
@pskink I tried that and it doesn't work. The second database is not found. — Hasen, Nov 03 '19 at 11:03
@pskink You can't do `return await db.execute` anyway though. — Hasen, Nov 03 '19 at 11:05
@pskink It definitely works as it is but it only creates one database. — Hasen, Nov 03 '19 at 11:05
@pskink To be honest I don't know what your code actually is. Can you write the entire function out? — Hasen, Nov 03 '19 at 11:07
what you dont know? `await` keyword? simply call two `db.execute` statements and wait for them to be finished by adding `await` keyword — pskink, Nov 03 '19 at 11:08
`await` is already in the function?? Not sure what you're saying, you're just saying bits and pieces and so I've no idea what your actual whole function is. — Hasen, Nov 03 '19 at 11:09
do you see `final dbPath = await sql.getDatabasesPath();` in your code? do the same with `db.execute` — pskink, Nov 03 '19 at 11:10
@pskink No idea what exactly you want to say...please write out the function or at least the code within the return statement. — Hasen, Nov 03 '19 at 11:11
i think that first you need to read [Asynchronous programming: futures, async, await](https://dart.dev/codelabs/async-await) - it explains how and when to use `await` keyword — pskink, Nov 03 '19 at 11:12
@pskink Again the function is **already** asynchronous, not sure why you think I don't know that that means. Anyway, I think we're looking at different things. — Hasen, Nov 03 '19 at 11:13
@pskink You obviously know what you mean but it's not guaranteed that that even works. Unless you can write clearly what you're saying I can't tell what you mean. — Hasen, Nov 03 '19 at 11:14
https://github.com/tekartik/sqflite/blob/master/sqflite/example/lib/type_test_page.dart#L118 here you have how to use `await` and `db.execute`, and here: https://github.com/tekartik/sqflite/tree/master/sqflite/example/lib you have more examples — pskink, Nov 03 '19 at 11:17
@pskink I got it to work in the end. There's no need for another `async` `await`, I just returned two `db.execute` from a separate function. The reason it wasn't working was because after deleting the original database I needed to restart the simulator from cold for it to take effect. — Hasen, Nov 03 '19 at 11:27
yes, you have to await for every `db.execute` - otherwise the strange race condition can happen — pskink, Nov 03 '19 at 11:32
@pskink No, I said there was no need for an additional `async` `await` since the function already has it. Check my answer below. — Hasen, Nov 03 '19 at 11:38
@pskink There's no need for `await` with `db.execute`. Try it yourself. — Hasen, Nov 03 '19 at 11:39

score 7 · Accepted Answer · answered Nov 03 '19 at 11:38

I managed to solve it myself like this:

   static Future<Database> database() async {
    final dbPath = await sql.getDatabasesPath();
    return sql.openDatabase(path.join(dbPath, 'mydatabase.db'), onCreate: (db, version) => _createDb(db), version: 1);
  }

  static void _createDb(Database db) {
    db.execute('CREATE TABLE mytable(date TEXT PRIMARY KEY, value DOUBLE)');
    db.execute('CREATE TABLE mytableb(date TEXT PRIMARY KEY, value DOUBLE)');
  }

The reason it wasn't working was because after deleting the original database I needed to restart the simulator from cold for it to take effect.

Flutter SQFLite create multiple tables at once

1 Answers1