openDatabase
- Flutter course
- Intermediate
- Lesson 42/99
- 4 min
Create a database with openDatabase.
Creating a table
To create a table, you run a CREATE TABLE SQL query with db.execute. The onCreate callback of openDatabase is called on first open.
await openDatabase(
'app.db',
version: 1,
onCreate: (db, version) async {
await db.execute(
'CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)'
);
},
);This query creates the table once.
onCreate callback
onCreate is called when the database is created for the first time. Here you define the tables. The version parameter specifies the table version; on change onUpgrade is triggered.
onCreate: (db, version) async {
await db.execute('CREATE TABLE ...');
},onCreate runs only once.
Practice Create the kullanicilar table
In the ac async method, call openDatabase. In the onCreate callback, run the query 'CREATE TABLE kullanicilar (id INTEGER PRIMARY KEY, isim TEXT)' with db.execute. In main, await ac and print 'tablo oluşturuldu'.
Starter code
import 'package:sqflite/sqflite.dart';
Future<void> ac() async {
// openDatabase ile onCreate içinde tablo oluştur
}
void main() async {
await ac();
print('tablo oluşturuldu');
}Sample solution
import 'package:sqflite/sqflite.dart';
Future<void> ac() async {
await openDatabase(
'uygulama.db',
version: 1,
onCreate: (db, version) async {
await db.execute(
'CREATE TABLE kullanicilar (id INTEGER PRIMARY KEY, isim TEXT)'
);
},
);
}
void main() async {
await ac();
print('tablo oluşturuldu');
}Expected output
tablo oluşturuldu
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Which SQL command is used to create a table?
- DELETE FROM
- CREATE TABLE Correct answer
- SELECT
- INSERT INTO
Explanation: The CREATE TABLE command defines and creates a table with its columns.
2 Run the CREATE TABLE query
await db.____(
'CREATE TABLE kullanicilar (id INTEGER PRIMARY KEY, isim TEXT)'
);await db.execute(
'CREATE TABLE kullanicilar (id INTEGER PRIMARY KEY, isim TEXT)'
);Explanation: SQL commands such as CREATE TABLE are run with db.execute; it is used for queries that do not return a value.
3 Table creation parts
| Term | Meaning |
|---|---|
CREATE TABLE |
SQL command creating the table |
onCreate |
Callback called on first open |
execute |
Method running SQL command |
version |
Parameter specifying table version |