How to update SQLite database from DataGridView in Visual Basic 2013 .net? - vb.net

Question

I am displaying data from SQLite table into a DataGridView as following -
Private Sub Subjects_Manager_Load(sender As Object, e As EventArgs) Handles MyBase.Load
con = New SQLiteConnection("Data Source = c:\demo\test.db;Version=3;")
con.Open()
sql = "SELECT * FROM med_subjects"
da = New SQLiteDataAdapter(sql, con)
da.Fill(ds, "SubjectsList")
DataGridView1.DataSource = ds.Tables("SubjectsList").DefaultView
With DataGridView1
.RowHeadersVisible = False
.Columns(0).HeaderCell.Value = "Subject Id"
.Columns(1).HeaderCell.Value = "Subject Name"
End With
DataGridView1.Sort(DataGridView1.Columns(0), System.ComponentModel.ListSortDirection.Ascending)
con.close()
End Sub
I want to save changes done in DataGridView (either Updation of Row/s or Insertion of Row/s) back to SQLite table. But I couldn't find a way to do so.
Edit 1 :
I know Insert/Update Queries of SQLite, but what I don't know is how & where to keep them so that they can be triggered in responses to changes made in DataGridView. e.g.
' I am using this variable for demonstration, in reality InsertSubjectSqlString will be equal to changes done in DataGridView
Dim InsertSubjectSqlString As String = "Insert into med_subjects (Subject_Name) Values ('_Miscellaneous')"
Dim SqliteInsertRow As SQLiteCommand
SqliteInsertRow = con.CreateCommand
SqliteInsertRow.CommandText = InsertSubjectSqlString
SqliteInsertRow.ExecuteNonQuery()
But I don't know, where should I put it?
Edit 2:
After seeing comments and answers, I came to know that there is No direct way to Insert/Update Sqlite database from DataGridView. So I was curious, if there is any event like RowSelected which would
trigger on selecting a row and get that row's data
then taking the row's data into multiple text boxes and lastly
triggering Insert/Update queries taking values from these textboxes
by a button
I know it's highly hypothetical with NO sample codes, but it's because I am asking for Event name.

Answer 1

Call this on LeaveRow event or CellEndEdit
Private Sub DataGridView1_RowLeave(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.RowLeave
Dim i as integer
Try
for i = 0 to datagrid.rows.count-1
myUpdate(datagrid.item(0,i).tostring() , datagrid.item(1,i).tostring())
next
Catch ex As Exception
MsgBox(Err.Description)
End Try
End Sub
note , you can also give the column name of your grid in place of column index , like this datagrid.item("fname",i).tostring()
Here we will save in database:
Sub myUpdate(byval fname as string , byval lname as string)
Try
dim con as new sqlconnection("you connection string")
dim cmd as new sqlcommand
con.open()
cmd.connection= con
cmd.commandtext="insert into table (fname,lname) values (#fname,#lname)"
cmd.Parameters.AddWithValue("#fname", fname)
cmd.Parameters.AddWithValue("#lname", lname)
cmd.ExecuteNonQuery()
Con.close()
Catch ex As Exception
MsgBox(Err.Description)
End Try
End sub
I hope this will help you to solve !
There are many ways to manipulate data .
CristiC

Answer 2

I dont think you will find some magic way that the DataGridView and DataTable are going to persist things automatically to the backend SQLite database. As you are hinting at I think you will have to rely on events.
I think the event you are missing is answered here stackoverflow cell value changed event

Answer 3

Ok I think is better to use CellEndEdit, because LeaveRow is triggered only if you click on other row.
Look on this example.
you must use: da.Update(ds.Tables("SubjectsList").DefaultView)
Imports System.Data.SqlClient
Public Class Form1
Const connectionstring As String = "server=(local);database=TestDB;uid=sa;pwd=sa;"
Private SQL As String = "select * from customer"
Private con As New SqlConnection(connectionstring)
Private dt As New DataTable
Private adapter As New SqlDataAdapter(SQL, con)
Private commandbuilder As New SqlCommandBuilder(adapter)
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
adapter.Fill(dt)
DataGridView1.DataSource = dt
End Sub
Private Sub DataGridView1_RowLeave(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.RowLeave
adapter.Update(dt)
End Sub
End Class

Answer 4

Please use this code hopefully it will work
Imports System.Data.SQLite
Public Class Form
Dim con As New SQLite.SQLiteConnection
Dim da As New SQLite.SQLiteDataAdapter
Dim dt As New DataTable
Dim cmdbl As New SQLite.SQLiteCommandBuilder
Dim dlgResult As DialogResult
Private Sub btnUpdate_Click(sender As Object, e As EventArgs) Handles btnUpdate.Click
dlgResult = MessageBox.Show("Do you want to save the changes you made?", "Confirmation!", MessageBoxButtons.YesNo)
If dlgResult = DialogResult.Yes Then
Try
con.Open()
cmdbl = New SQLiteCommandBuilder(da)
da.Update(dt)
MsgBox("Updated successfully!")
con.Close()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End If
End Sub
End Class