SQFlite Single Json Local Storage in flutter

 SQFlite Single Json in flutter

{

"id" : 1,

"name" : "Avi",

"age" : 22

}

1.            UserModel

class UserModel{
  // final int id;
  final int id;
  final String name;
  final int age;

  // constructor
  UserModel({
    // required this.id,
    required this.id,
    required this.name,
    required this.age
});

  factory UserModel.fromMap(Map<String,dynamic>map){
    return UserModel(
        id: map['id'],
        name: map['name'],
        age: map['age']
    );
  }

  Map<String, dynamic> toJson(){
    return {
      "id" : id,
      "name" : name,
      "age" : age
    };
  }

}

2.            Dbhandler

import 'dart:convert';
import 'dart:io';

import 'package:healthtick/model/user_model.dart';
import 'package:healthtick/model/vendor_dj_model.dart';
import 'package:path_provider/path_provider.dart';
import 'package:sqflite/sqflite.dart';
import 'package:path/path.dart';
import 'package:healthtick/model/book_model.dart';



class DbHandler {
  Database? _database;

  Future<Database?> get database async {
    if (_database != null) {
      return _database;
    }

//     Create Database file in your mobile
    Directory directory = await getApplicationDocumentsDirectory();
    String path = join(directory.path, "mydatabase.db");

//   open & create table in database file
    _database = await openDatabase(path, version: 1, onCreate: (db, version) {
      db.execute('''
      CREATE TABLE DatabaseTable(
      id INTEGER PRIMARY KEY,
      name TEXT,
      age INTEGER
      )
      ''');
      
    });
    return _database!;
  }

//   Insert Data with help User Model Class
  insertData(UserModel userModel) async {
    Database? db = await database;
    await db!.insert('DatabaseTable', userModel.toJson());
  }
// Fetch/ Read Data in Database Table
  Future<List<UserModel>>readData() async {
    Database? db = await database;
    final data = await db!.query("DatabaseTable");
    // return data;
    //   With model
    return data.map((map) => UserModel.fromMap(map)).toList();
  }
//   Delete Data in Database Table
deleteData(int id)async{
    Database? db=await database;
    await db!.delete('DatabaseTable' , where: 'id=?',whereArgs: [id]);
}

//   Update Data in Database Table
  updateData(UserModel userModel) async {
    Database? db = await database;
    await db!.update(
        'DatabaseTable',
        where: 'id=?',
        whereArgs: [userModel.id],
        userModel.toJson());
  } 

}

3.            Calling (insert & read Method)

ElevatedButton(child: Text("Insert"),
onPressed: ()async{
  // await DbHandler().insertData(3, "Shesha", 22);
  // await DbHandler().insertData(
     
 
  //     UserModel(
  
       id: 5,
      name: "Radhe",
      age: 23
    // name: nameController.text,
    // age: int.parse(ageController.text),
    
        
         

  );
  print("Inserted");
  print(nameController.text + ageController.text);

},),
ElevatedButton(child: Text("Read/Fetch"),
  onPressed: ()async{
    // final data=await DbHandler().readData();
    final data=await DbHandler().readBook();
    print("Fetch");
    print(data);

  },),
ElevatedButton(child: Text("Delete"),
  onPressed: ()async{
    final data=await DbHandler().deleteData(4);
    print("Delete");
  },),

// ElevatedButton(child: Text("Update"),
//   onPressed: ()async{
//     final data=await DbHandler().updateData(
//       //   {
//       // 'id' : 3,
//       // 'name' : "Anuradha",
//       // 'age': 46
//       //   }
//       UserModel(
//           name: nameController.text,
//           age: int.parse(ageController.text),
//       )
//     );
//     print("Updated");
//   },),

4.            Fetch Data

import 'package:flutter/material.dart';
import 'package:healthtick/Sqflite/db_handler.dart';
import 'package:healthtick/model/user_model.dart';

import 'model/book_model.dart';

class UserScreen extends StatefulWidget {
  const UserScreen({super.key});

  @override
  State<UserScreen> createState() => _UserScreenState();
}

class _UserScreenState extends State<UserScreen> {
  TextEditingController nameController= TextEditingController();
  TextEditingController ageController= TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("User Screen"),
        backgroundColor: Colors.yellow,
      ),
      body: SafeArea(
        child: FutureBuilder(
          
          future: DbHandler().readData(),
           builder: (context, AsyncSnapshot<List<UserModel>> snapshot) {

            if(!snapshot.hasData) return CircularProgressIndicator();
            return ListView.builder(
              itemCount: snapshot.data!.length,
              itemBuilder: (context, index) {
                
                nameController.text=snapshot.data![index].name ;
                ageController.text=snapshot.data![index].age.toString();


                return ListTile(
                  
                   title: Text(snapshot.data![index].name),
                   subtitle: Text(snapshot.data![index].age.toString()),
                  trailing: SizedBox(
                    width: 200,
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: [
                        ElevatedButton(
                          child: Text("Update"),
                          onPressed: ()async{
                            int id=int.parse(snapshot.data![index].id.toString());
                            print(id);
                            showDialog(
                                context: context,
                                builder: (context) => AlertDialog(
                                  title: Text("Update Dialog"),
                                  content: Column(
                                    children: [
                                      TextField(
                                        controller: nameController,
                                        decoration: InputDecoration(
                                            filled: true,
                                            fillColor: Colors.white,
                                            hintText: "Enter your name",
                                            labelText: "Name"
                                        ),
                                      ),
                                      SizedBox(height: 5,),
                                      TextField(
                                        controller: ageController,
                                        keyboardType: TextInputType.number,
                                        decoration: InputDecoration(
                                            filled: true,
                                            fillColor: Colors.white,
                                            hintText: "Enter your age",
                                            labelText: "Age"
                                        ),
                                      ),
                                    ],
                                  ),
                                  actions: <Widget>[
                                    TextButton(
                                        onPressed: ()async{
                                          int id=int.parse(snapshot.data![index].id.toString());
                                          print(id);
                                          await DbHandler().updateData(UserModel(
                                            id: id,
                                            name: nameController.text,
                                            age: int.parse(ageController.text),
                                          ));
                                          // Navigator.pop(context);
                                          Navigator.pushReplacement(context, MaterialPageRoute(builder: (context)=>UserScreen()));
                                        },
                                        child: Text("Submit"))
                                  ],
                                ),
                            );
                            // await DbHandler().updateData(
                            //     UserModel(
                            //       name: nameController.text,
                            //       age: int.parse(ageController.text),
                            //     )
                            // );
                            print("Update");
                          },
                        ),
                        ElevatedButton(
                          child: Text("Delete"),
                          onPressed: ()async{
                            int id=int.parse(snapshot.data![index].id.toString());
                            print(id);
                            await DbHandler().deleteData(id);
                            print("Deleted");
                            await Navigator.push(context, MaterialPageRoute(builder: (context) => UserScreen()));
                          },
                        ),
                      ],
                    ),
                  ),
                );
              },
            );
          },

        ),
      ),
    );
  }
}