Summary - Database
- Dart course
- Advanced
- Lesson 48/83
- 5 min
Combine sqflite, CRUD and transactions to write a user database.
Summary - Database
In this group we learned local database management with Dart. sqflite provides embedded SQLite; Database is the connection object; CRUD operations (insert/query/update/delete) manage data; transaction adds atomicity; drift builds a type-safe ORM on top.
In this summary we combine sqflite setup and a CRUD operation: a setupDb function opens the database and creates a table; an addNote function inserts a note. This is a small but working example of a real application's data layer.
Practice Setup and add a note
The code below imports sqflite. Define setupDb(): open with openDatabase('notes.db'), create the table with db.execute('CREATE TABLE notes (id INTEGER PRIMARY KEY, title TEXT)') and return db. Define addNote(Database db): insert with db.insert('notes', {'title': 'Summary note'}). In main add print('Summary: sqflite + CRUD'), await setupDb(), await addNote(db), print('Added: Summary note') and await db.close().
Starter code
import 'package:sqflite/sqflite.dart';
Future<Database> setupDb() async {
// open notes.db, create notes table, return db
}
Future<void> addNote(Database db) async {
// insert a note (db.insert)
}
void main() async {
// print summary message, call setupDb and addNote, close
}Sample solution
import 'package:sqflite/sqflite.dart';
Future<Database> setupDb() async {
final db = await openDatabase('notes.db');
await db.execute('CREATE TABLE notes (id INTEGER PRIMARY KEY, title TEXT)');
return db;
}
Future<void> addNote(Database db) async {
await db.insert('notes', {'title': 'Summary note'});
}
void main() async {
print('Summary: sqflite + CRUD');
final db = await setupDb();
await addNote(db);
print('Added: Summary note');
await db.close();
}Expected output
Summary: sqflite + CRUD Added: Summary note
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Which one is the atomic operation?
- db.close
- db.query
- db.execute
- Transaction Correct answer
Explanation: a transaction runs multiple operations atomically.
2 Match the database concepts
| Term | Meaning |
|---|---|
sqflite |
Embedded SQLite |
Database |
Connection |
CRUD |
insert/query/update/delete |
drift |
ORM |
3 The db.transaction call
await db.____((txn) async {
await txn.insert('notes', {'title': 'Summary note'});
});await db.transaction((txn) async {
await txn.insert('notes', {'title': 'Summary note'});
});Explanation: db.transaction starts the atomic block.