# Working with local databases

# Using SQLite.NET in a Shared Project

SQLite.NET is an open source library which makes it possible to add local-databases support using SQLite version 3 in a Xamarin.Forms project.

The steps below demonstrate how to include this component in a Xamarin.Forms Shared Project:

  • Download the latest version of the [SQLite.cs](https://github.com/praeclarum/sqlite-net/blob/master/src/SQLite.cs) class and add it to the Shared Project.

  • Every table that will be included in the database needs to be modeled as a class in the Shared Project. A table is defined by adding at least two attributes in the class: `Table` (for the class) and `PrimaryKey` (for a property).
  • For this example, a new class named Song is added to the Shared Project, defined as follows:

    using System;
    using SQLite;
    
    namespace SongsApp
    {
        [Table("Song")]
        public class Song
        {
            [PrimaryKey]
            public string ID { get; set; }
            public string SongName { get; set; }
            public string SingerName { get; set; }
        }
    }
    
    
    1. Next, add a new class called Database, which inherits from the SQLiteConnection class (included in SQLite.cs). In this new class, the code for database access, tables creation and CRUD operations for each table is defined. Sample code is shown below:
    using System;
    using System.Linq;
    using System.Collections.Generic;
    using SQLite;
    
    namespace SongsApp
    {
        public class BaseDatos : SQLiteConnection
        {
            public BaseDatos(string path) : base(path)
            {
                Initialize();
            }
    
            void Initialize()
            {
                CreateTable<Song>();
            }
    
            public List<Song> GetSongs()
            {
                return Table<Song>().ToList();
            }
    
            public Song GetSong(string id)
            {
                return Table<Song>().Where(t => t.ID == id).First();
            }
    
            public bool AddSong(Song song)
            {
                Insert(song);
            }
    
            public bool UpdateSong(Song song)
            {
                Update(song);
            }
    
            public void DeleteSong(Song song)
            {
                Delete(song);
            }
        }
    }
    
    
    1. As you could see in the previous step, the constructor of our Database class includes a path parameter, which represents the location of the file that stores the SQLite database file. A static Database object can be declared in App.cs. The path is platform-specific:
    public class App : Application
    {
        public static Database DB;
    
        public App ()
        {
            string dbFile = "SongsDB.db3";
    
    #if __ANDROID__
            string docPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
            var dbPath = System.IO.Path.Combine(docPath, dbFile);
    #else
    #if __IOS__
            string docPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
            string libPath = System.IO.Path.Combine(docPath, "..", "Library");
            var dbPath = System.IO.Path.Combine(libPath, dbFile);
    #else
            var dbPath = System.IO.Path.Combine(ApplicationData.Current.LocalFolder.Path, dbFile);
    #endif
    #endif
    
            DB = new Database(dbPath);
    
            // The root page of your application
            MainPage = new SongsPage();
        }
    }
    
    
    1. Now simply call the DB object through the App class anytime you need to perform a CRUD operation to the Songs table. For example, to insert a new Song after the user has clicked a button, you can use the following code:
    void AddNewSongButton_Click(object sender, EventArgs a)
    {
        Song s = new Song();
        s.ID = Guid.NewGuid().ToString();
        s.SongName = songNameEntry.Text;
        s.SingerName = singerNameEntry.Text;
    
        App.DB.AddSong(song);
    }
    
    

    # Working with local databases using xamarin.forms in visual studio 2015

    SQlite example Step by step Explanation

  • The steps below demonstrate how to include this component in a Xamarin.Forms Shared Project: to add packages in (pcl,Andriod,Windows,Ios) Add References Click on **Manage Nuget packages** ->click on Browse to install **SQLite.Net.Core-PCL** , **SQLite Net Extensions** after installation is completed check it once in references then

  • To add Class **Employee.cs** below code
     using SQLite.Net.Attributes;
    
         namespace DatabaseEmployeeCreation.SqlLite
         {
             public   class Employee
             {
                 [PrimaryKey,AutoIncrement]
                 public int Eid { get; set; }
                 public string Ename { get; set; }
                 public string Address { get; set; }
                 public string phonenumber { get; set; }
                 public string email { get; set; } 
             }
         }
    
    
  • To add one interface ISQLite
  • 
    using SQLite.Net;  
                //using SQLite.Net;
                namespace DatabaseEmployeeCreation.SqlLite.ViewModel
                {
                    public interface ISQLite
                    {
                        SQLiteConnection GetConnection();
                    }
                }
    
    
    1. Create a one class for database logics and methods below code is follow .

    using SQLite.Net; using System.Collections.Generic; using System.Linq; using Xamarin.Forms; namespace DatabaseEmployeeCreation.SqlLite.ViewModel { public class DatabaseLogic { static object locker = new object(); SQLiteConnection database;

    
       public DatabaseLogic()
        {
            database = DependencyService.Get<ISQLite>().GetConnection();
            // create the tables
            database.CreateTable<Employee>();
        }
    
        public IEnumerable<Employee> GetItems()
        {
            lock (locker)
            {
                return (from i in database.Table<Employee>() select i).ToList();
            }
        }
    
        public IEnumerable<Employee> GetItemsNotDone()
        {
            lock (locker)
            {
                return database.Query<Employee>("SELECT * FROM [Employee]");
            }
        }
    
        public Employee GetItem(int id)
        {
            lock (locker)
            {
                return database.Table<Employee>().FirstOrDefault(x => x.Eid == id);
            }
        }
    
        public int SaveItem(Employee item)
        {
            lock (locker)
            {
                if (item.Eid != 0)
                {
                    database.Update(item);
                    return item.Eid;
                }
                else
                {
                    return database.Insert(item);
                }
            }
        }
    
        public int DeleteItem(int Eid)
        {
            lock (locker)
            {
                return database.Delete<Employee>(Eid);
            }
        }
    }
    
    

    }

    1. to Create a xaml.forms EmployeeRegistration.xaml
    
       <?xml version="1.0" encoding="utf-8" ?>
        <ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
                     xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                     x:Class="DatabaseEmployeeCreation.SqlLite.EmployeeRegistration"
          Title="{Binding Name}" >
          <StackLayout VerticalOptions="StartAndExpand" Padding="20">
        
            <Label Text="Ename" />
            <Entry x:Name="nameEntry" Text="{Binding Ename}"/>
            <Label Text="Address" />
            <Editor x:Name="AddressEntry" Text="{Binding Address}"/>
            <Label Text="phonenumber" />
            <Entry x:Name="phonenumberEntry" Text="{Binding phonenumber}"/>
            <Label Text="email" />
            <Entry x:Name="emailEntry" Text="{Binding email}"/>
        
            <Button Text="Add" Clicked="addClicked"/>
        
           <!-- <Button Text="Delete" Clicked="deleteClicked"/>-->
        
            <Button Text="Details" Clicked="DetailsClicked"/>
        
            <!--  <Button Text="Edit" Clicked="speakClicked"/>-->
        
          </StackLayout>
        </ContentPage>
    
    

    EmployeeRegistration.cs

    
       using DatabaseEmployeeCreation.SqlLite.ViewModel;
        using DatabaseEmployeeCreation.SqlLite.Views;
        using System;
        using System.Collections.Generic;
        using System.Linq;
        using System.Text;
        using System.Threading.Tasks;
        
        using Xamarin.Forms;
        
        namespace DatabaseEmployeeCreation.SqlLite
        {
            public partial class EmployeeRegistration : ContentPage
            {
                private int empid;
                private Employee obj;
        
                public EmployeeRegistration()
                {
                    InitializeComponent();
        
                }
        
                public EmployeeRegistration(Employee obj)
                {
                    this.obj = obj;
                    var eid = obj.Eid;
                    Navigation.PushModalAsync(new EmployeeRegistration());
                    var Address = obj.Address;
                    var email = obj.email;
                    var Ename = obj.Ename;
                    var phonenumber = obj.phonenumber;
                    AddressEntry. = Address;
                    emailEntry.Text = email;
                    nameEntry.Text = Ename;
        
                    //AddressEntry.Text = obj.Address;
                    //emailEntry.Text = obj.email;
                    //nameEntry.Text = obj.Ename;
                    //phonenumberEntry.Text = obj.phonenumber;
        
                    Employee empupdate = new Employee(); //updateing Values 
                    empupdate.Address = AddressEntry.Text;
                    empupdate.Ename = nameEntry.Text; 
                    empupdate.email = emailEntry.Text;
                    empupdate.Eid = obj.Eid;
                    App.Database.SaveItem(empupdate);
                    Navigation.PushModalAsync(new EmployeeRegistration());
                  
                }
        
                public EmployeeRegistration(int empid)
                {
                    this.empid = empid;
                    Employee lst = App.Database.GetItem(empid);
                    //var Address = lst.Address;
                    //var email = lst.email;
                    //var Ename = lst.Ename;
                    //var phonenumber = lst.phonenumber;
                    //AddressEntry.Text = Address;
                    //emailEntry.Text = email;
                    //nameEntry.Text = Ename;
                    //phonenumberEntry.Text = phonenumber;
        
                    // to retriva values based on id to 
                    AddressEntry.Text = lst.Address;
                    emailEntry.Text = lst.email;
                    nameEntry.Text = lst.Ename;
                    phonenumberEntry.Text = lst.phonenumber;
                    
                    Employee empupdate = new Employee(); //updateing Values 
                    empupdate.Address = AddressEntry.Text;
                    empupdate.email = emailEntry.Text;
                    App.Database.SaveItem(empupdate);
                    Navigation.PushModalAsync(new EmployeeRegistration());
                }
        
                void addClicked(object sender, EventArgs e)
                {
                    //var createEmp = (Employee)BindingContext;
                    Employee emp = new Employee();
                    emp.Address = AddressEntry.Text;
                    emp.email = emailEntry.Text;
                    emp.Ename = nameEntry.Text;
                    emp.phonenumber = phonenumberEntry.Text;
                    App.Database.SaveItem(emp);
                    this.Navigation.PushAsync(new EmployeeDetails());
        
                }
                //void deleteClicked(object sender, EventArgs e)
                //{
                //    var emp = (Employee)BindingContext;
                //    App.Database.DeleteItem(emp.Eid);
                //    this.Navigation.PopAsync();
                //}
                void DetailsClicked(object sender, EventArgs e)
                {
                    var empcancel = (Employee)BindingContext;
                    this.Navigation.PushAsync(new EmployeeDetails());
                }
                //    void speakClicked(object sender, EventArgs e)
                //    {
                //        var empspek = (Employee)BindingContext;
                //        //DependencyService.Get<ITextSpeak>().Speak(empspek.Address + " " + empspek.Ename);
                //    }
            }
        }
    
    
  • to display EmployeeDetails below code behind
     using DatabaseEmployeeCreation;
     using DatabaseEmployeeCreation.SqlLite;
     using System;
     using System.Collections.Generic;
     using System.Linq;
     using System.Text;
     using System.Threading.Tasks;
     
     using Xamarin.Forms;
     
     namespace DatabaseEmployeeCreation.SqlLite.Views
     {
         public partial class EmployeeDetails : ContentPage
         {
             ListView lv = new ListView();
             IEnumerable<Employee> lst;
             public EmployeeDetails()
             {
                 InitializeComponent();
                 displayemployee();
             }
     
             private void displayemployee()
             {
                 Button btn = new Button()
                 {
     
                     Text = "Details",
                     BackgroundColor = Color.Blue,
                 };
                 btn.Clicked += Btn_Clicked;
                 //IEnumerable<Employee> lst = App.Database.GetItems();
                 //IEnumerable<Employee> lst1 = App.Database.GetItemsNotDone();
                 //IEnumerable<Employee> lst2 = App.Database.GetItemsNotDone();
                 Content = new StackLayout()
                 {
                     Children = { btn },
                 };
             }
     
             private void Btn_Clicked(object sender, EventArgs e)
             {
                 lst = App.Database.GetItems();
     
                 lv.ItemsSource = lst;
                 lv.HasUnevenRows = true;
                 lv.ItemTemplate = new DataTemplate(typeof(OptionsViewCell));
     
                 Content = new StackLayout()
                 {
                     Children = { lv },
                 };
     
             }
         }
    
    
  • 
           public class OptionsViewCell : ViewCell
            {
        
                int empid;
                Button btnEdit;
                public OptionsViewCell()
                {
                }
                protected override void OnBindingContextChanged()
                {
                    base.OnBindingContextChanged();
        
                    if (this.BindingContext == null)
                        return;
        
                    dynamic obj = BindingContext;
                    empid = Convert.ToInt32(obj.Eid);
                    var lblname = new Label
                    {
                        BackgroundColor = Color.Lime,
                        Text = obj.Ename,
                    };
        
                    var lblAddress = new Label
                    {
                        BackgroundColor = Color.Yellow,
                        Text = obj.Address,
                    };
        
                    var lblphonenumber = new Label
                    {
                        BackgroundColor = Color.Pink,
                        Text = obj.phonenumber,
                    };
        
                    var lblemail = new Label
                    {
                        BackgroundColor = Color.Purple,
                        Text = obj.email,
                    };
        
                    var lbleid = new Label
                    {
                        BackgroundColor = Color.Silver,
                        Text = (empid).ToString(),
                    };
        
                    //var lblname = new Label
                    //{
                    //    BackgroundColor = Color.Lime,
                    //    // HorizontalOptions = LayoutOptions.Start
                    //};
                    //lblname.SetBinding(Label.TextProperty, "Ename");
        
                    //var lblAddress = new Label
                    //{
                    //    BackgroundColor = Color.Yellow,
                    //    //HorizontalOptions = LayoutOptions.Center,
                    //};
                    //lblAddress.SetBinding(Label.TextProperty, "Address");
        
                    //var lblphonenumber = new Label
                    //{
                    //    BackgroundColor = Color.Pink,
                    //    //HorizontalOptions = LayoutOptions.CenterAndExpand,
                    //};
                    //lblphonenumber.SetBinding(Label.TextProperty, "phonenumber");
        
                    //var lblemail = new Label
                    //{
                    //    BackgroundColor = Color.Purple,
                    //    // HorizontalOptions = LayoutOptions.CenterAndExpand
                    //};
                    //lblemail.SetBinding(Label.TextProperty, "email");
                    //var lbleid = new Label
                    //{
                    //    BackgroundColor = Color.Silver,
                    //    // HorizontalOptions = LayoutOptions.CenterAndExpand
                    //};
                    //lbleid.SetBinding(Label.TextProperty, "Eid");
                    Button btnDelete = new Button
                    {
                        BackgroundColor = Color.Gray,
        
                        Text = "Delete",
                        //WidthRequest = 15,
                        //HeightRequest = 20,
                        TextColor = Color.Red,
                        HorizontalOptions = LayoutOptions.EndAndExpand,
                    };
                    btnDelete.Clicked += BtnDelete_Clicked;
                    //btnDelete.PropertyChanged += BtnDelete_PropertyChanged;  
        
                    btnEdit = new Button
                    {
                        BackgroundColor = Color.Gray,
                        Text = "Edit",
                        TextColor = Color.Green,
                    };
                    // lbleid.SetBinding(Label.TextProperty, "Eid");
                    btnEdit.Clicked += BtnEdit_Clicked1; ;
                    //btnEdit.Clicked += async (s, e) =>{
                    //    await App.Current.MainPage.Navigation.PushModalAsync(new EmployeeRegistration());
                    //};
        
                    View = new StackLayout()
                    {
                        Orientation = StackOrientation.Horizontal,
                        BackgroundColor = Color.White,
                        Children = { lbleid, lblname, lblAddress, lblemail, lblphonenumber, btnDelete, btnEdit },
                    };
        
                    //View = new StackLayout()
                    //{ HorizontalOptions = LayoutOptions.Center, WidthRequest = 10, BackgroundColor = Color.Yellow, Children = { lblAddress } };
        
                    //View = new StackLayout()
                    //{ HorizontalOptions = LayoutOptions.End, WidthRequest = 30, BackgroundColor = Color.Yellow, Children = { lblemail } };
        
                    //View = new StackLayout()
                    //{ HorizontalOptions = LayoutOptions.End, BackgroundColor = Color.Green, Children = { lblphonenumber } };
        
        
        
        
                    //string Empid =c.eid ;
        
                }
        
                private async void BtnEdit_Clicked1(object sender, EventArgs e)
                {
                   Employee obj= App.Database.GetItem(empid);
                    if (empid > 0)
                    {
                        await App.Current.MainPage.Navigation.PushModalAsync(new EmployeeRegistration(obj));
                    }
                    else {
                    await App.Current.MainPage.Navigation.PushModalAsync(new EmployeeRegistration(empid));
                    }
                }
        
        
        
                private void BtnDelete_Clicked(object sender, EventArgs e)
                {
                    // var eid = Convert.ToInt32(empid);
                    // var item = (Xamarin.Forms.Button)sender;
                    int eid = empid;
                    App.Database.DeleteItem(eid);
                }
                //private void BtnDelete_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
                //{
                // var ename=  e.PropertyName;
                //}
            }
        
            //private void BtnDelete_Clicked(object sender, EventArgs e)
            //{
            //    var eid = 8;
            //    var item = (Xamarin.Forms.Button)sender;
        
            //    App.Database.DeleteItem(eid);
            //}
        }
    
    
    1. To implement method in Android and ios GetConnection() method
    
       using System;
        using Xamarin.Forms;
        using System.IO;
        using DatabaseEmployeeCreation.Droid;
        using DatabaseEmployeeCreation.SqlLite.ViewModel;
        using SQLite;
        using SQLite.Net;
        
        [assembly: Dependency(typeof(SQLiteEmployee_Andriod))]
        namespace DatabaseEmployeeCreation.Droid
        {
            public class SQLiteEmployee_Andriod : ISQLite
            {
                public SQLiteEmployee_Andriod()
                {
                }
        
                #region ISQLite implementation
                public SQLiteConnection GetConnection()
                {
                    //var sqliteFilename = "EmployeeSQLite.db3";
                    //string documentsPath = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal); // Documents folder
                    //var path = Path.Combine(documentsPath, sqliteFilename);
        
                    //// This is where we copy in the prepopulated database
                    //Console.WriteLine(path);
                    //if (!File.Exists(path))
                    //{
                    //    var s = Forms.Context.Resources.OpenRawResource(Resource.Raw.EmployeeSQLite);  // RESOURCE NAME ###
        
                    //    // create a write stream
                    //    FileStream writeStream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write);
                    //    // write to the stream
                    //    ReadWriteStream(s, writeStream);
                    //}
        
                    //var conn = new SQLiteConnection(path);
        
                    //// Return the database connection 
                    //return conn;
                    var filename = "DatabaseEmployeeCreationSQLite.db3";
                    var documentspath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
                    var path = Path.Combine(documentspath, filename);
                    var platform = new SQLite.Net.Platform.XamarinAndroid.SQLitePlatformAndroid();
                    var connection = new SQLite.Net.SQLiteConnection(platform, path);
                    return connection;
                }
        
                //public  SQLiteConnection GetConnection()
                //{
                //    var filename = "EmployeeSQLite.db3";
                //    var documentspath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
                //    var path = Path.Combine(documentspath, filename);
        
                //    var platform = new SQLite.Net.Platform.XamarinAndroid.SQLitePlatformAndroid();
                //    var connection = new SQLite.Net.SQLiteConnection(platform, path);
                //    return connection;
                //}
                #endregion
        
                /// <summary>
                /// helper method to get the database out of /raw/ and into the user filesystem
                /// </summary>
                void ReadWriteStream(Stream readStream, Stream writeStream)
                {
                    int Length = 256;
                    Byte[] buffer = new Byte[Length];
                    int bytesRead = readStream.Read(buffer, 0, Length);
                    // write the required bytes
                    while (bytesRead > 0)
                    {
                        writeStream.Write(buffer, 0, bytesRead);
                        bytesRead = readStream.Read(buffer, 0, Length);
                    }
                    readStream.Close();
                    writeStream.Close();
                }
            }
        }
    
    

    I hope this above example is very easy way i explained