Sqlcool #

A database helper library for Sqflite. Forget about implementation details and focus on the business logic.

• Simple: easy api for crud operations
• Reactive: stream of changes, select bloc

Check the documentation or the api doc for usage instructions

Simple crud #

Define the database schema #

import 'package:sqlcool/sqlcool.dart';

Db db = Db();
// define the database schema
DbTable category = DbTable("category")..varchar("name", unique: true);
DbTable product = DbTable("product")
   ..varchar("name", unique: true)
   ..integer("price")
   ..text("descripton", nullable: true)
   ..foreignKey("category", onDelete: OnDelete.cascade)
   ..index("name");
List<DbTable> schema = [category, product];

Initialize the database #

String dbpath = "db.sqlite"; // relative to the documents directory
await db.init(path: dbpath, schema: schema).catchError((e) {
  throw("Error initializing the database: ${e.message}");
});

Insert #

Map<String, String> row = {name: "My item",};
await db.insert(table: "category", row: row).catchError((e) {
  throw("Error inserting data: ${e.message}");
});

Select #

List<Map<String, dynamic>> rows = await db.select(
   table: "product", limit: 20, columns: "id,name",
   where: "name LIKE '%something%'",
   orderBy: "name ASC").catchError((e) {
    throw("Error selecting data: ${e.message}");
});

Update #

int updated = await db.update(table: "category", 
   row: row, where: "id=1").catchError((e) {
      throw("Error updating data: ${e.message}");
});

Delete #

db.delete(table: "category", where: "id=3").catchError((e) {
   throw("Error deleting data: ${e.message}");
});

Reactivity #

Changefeed #

A stream of database change events is available

import 'dart:async';
import 'package:sqlcool/sqlcool.dart';

StreamSubscription changefeed;

changefeed = db.changefeed.listen((change) {
   print("Change in the database:");
   print("Query: ${change.query}");
   if (change.type == DatabaseChange.update) {
     print("${change.value} items updated");
   }
 });
// Dispose the changefeed when finished using it
changefeed.cancel();

Reactive select bloc #

The bloc will rebuild itself on any database change because of the reactive parameter set to true:

import 'package:flutter/material.dart';
import 'package:sqlcool/sqlcool.dart';

class _PageSelectBlocState extends State<PageSelectBloc> {
  SelectBloc bloc;

  @override
  void initState() {
    super.initState();
    this.bloc = SelectBloc(
        table: "items", orderBy: "name", reactive: true);
  }

  @override
  void dispose() {
    bloc.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("My app")),
      body: StreamBuilder<List<Map>>(
          stream: bloc.items,
          builder: (BuildContext context, AsyncSnapshot snapshot) {
            if (snapshot.hasData) {
              // the select query has not found anything
              if (snapshot.data.length == 0) {
                return Center(child: const Text("No data"));
              }
              // the select query has results
              return ListView.builder(
                  itemCount: snapshot.data.length,
                  itemBuilder: (BuildContext context, int index) {
                    var item = snapshot.data[index];
                    return ListTile(
                      title: GestureDetector(
                        child: Text(item["name"]),
                        onTap: () => someFunction()),
                    );
                  });
            } else {
              // the select query is still running
              return CircularProgressIndicator();
            }
          }),
    );
  }
}

class PageSelectBloc extends StatefulWidget {
  @override
  _PageSelectBlocState createState() => _PageSelectBlocState();
}

Using this #

• Sqlview: admin view and infinite list view
• Kvsql: a key/value store
• Geopoint sql: sql operations for geospatial data