How to save and clean a specific database if there are 2 or more data?

yan cus

5y1.1kXAML

How to save and clean a specific database if there are 2 or more data models in one database file.

previously I have created a data model as below. I have successfully loaded the data into a listView for the public class student.

Then, how do you access data from a public class school that is only input once without using a listView and PrimaryKey?

using SQLite;
using System;
namespace SchoolData.Models {
public class Student {
[PrimaryKey, AutoIncrement] public int IdSis {
get;
set;
}
public DateTime Date {
get;
set;
}
public string PicStudent {
get;
set;
}
}
public class School {
public string SchoolName {
get;
set;
}
//without primary key or single entry
public string Address {
get;
set;
}
public string Vision {
get;
set;
}
}
}

XamlPage code overview:

"School Name:"/>
"{Binding SchoolName}"/>
"Address:"/>
"{Binding Address}"/>
"Vision:"/>
"{Binding Vision}"/>
"Save" Clicked="SaveClick"/>
//save all entry
"Clear" Clicked="ClearClick"/> //clear all entry

Thank's.

6 Replies

Know the answer? Post it — somebody with the same question will find it here.

yan cus5y ago
I have successfully create and loaded the data into a listView for the public class student. but to access publicclassschool and put in the entry i'm still confused.
I use this for app.cs
public static DataSiswa Dtsiswa
{
get
{
if (dtsiswa == null)
{
dtsiswa = new
DataSiswa(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
"siswa.db3"));
}
return dtsiswa;
}
}
for connection.
public DataSiswa(string dbPath)
{
_database = new SQLiteAsyncConnection(dbPath);
_database.CreateTableAsync().Wait();
}
public Task> GetAdmKelasAsync()
{
return _database.Table().ToListAsync();
}
public Task GetSiswaAsync(int id)
{
return _database.Table()
.Where(i => i.IdSis == id)
.FirstOrDefaultAsync();
}
public Task<int> SaveSiswaAsync(Siswa siswa)
{
if (siswa.IdSis != 0)
{
return _database.UpdateAsync(siswa);
}
else
{
return _database.InsertAsync(siswa);
}
}
public Task<int> DeleteSiswaAsync(Siswa siswa)
{
return _database.DeleteAsync(siswa);
}
and from *.xaml
protected override async void OnAppearing()
{
base.OnAppearing();
daftarSiswa.ItemsSource = await App.Dtsiswa.GetAdmKelasAsync();
}
async void OnTambahAddedClicked(object sender, EventArgs e)
{
await Navigation.PushAsync(new EditSiswa
{
BindingContext = new Siswa()
});
}

async void OnListViewItemSelected(object sender, SelectedItemChangedEventArgs e)
{
if (e.SelectedItem != null)
{
await Navigation.PushAsync(new EditSiswa
{
BindingContext = e.SelectedItem as Siswa
});
}
}
Amit Gupta5y ago
Connecting to the database doesn't require any primary key. It belongs to the datatable.

Follow the basic procedure

CREATE A CONNECTION STRING
string connectionString = @"Data Source=PATH_TO_DB_FILE\...\file.ABC;
Version=3;";
GETTING CONNECTION
using (SQLiteConnection conn = new SQLiteConnection(connectionString))
       {
           conn.Open();
           // your rest code goes here
       }
That't it.
yan cus5y ago
I did not find the answer there. i want about how to make database connection without primary key and without using listView to xamlpage.
Amit Gupta5y ago
You can go through the article that performs CRUD operations https://www.codeproject.com/Tips/1057992/Using-SQLite-An-Example-of-CRUD-Operations-in-Csha
yan cus5y ago
@Amit_Gupta
I mean just saving and cleaning entries in the database contents. sorry my English is not good.. :(
Amit Gupta5y ago
Can you please elaborate your question?

Save and clean a database? Are you asking about to clear the class models that were binded with the controls or something else?