I am loading a VB.NET DataGridView using an SqlDataAdapter to fill a DataSet and then setting the DataSource of the DataGridView to the DataSet.
For some reason, the only command that is populated with the SqlCommandBuilder is the SelectCommand. I realize I am only specifying a SELECT query, but I thought the purpose of the SqlCommandBuilder is to generate the Update/Delete/Insert command for me.
The following is the applicable code:
Dim _dstErrorLog As New DataSet
Dim _adapter As SqlDataAdapter
Dim _builder As SqlCommandBuilder
Private Sub ErrorLog_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Call LoadErrorLog()
End Sub
Private Sub LoadErrorLog()
Dim strSql As String
strSql = "SELECT Ident, LogDate, LogDesc FROM dbo.ErrorLog ORDER BY DescDateTime DESC"
_adapter = New SqlDataAdapter(strSql, dataLayer.Connection)
_builder = New SqlCommandBuilder(_adapter)
_adapter.Fill(_dstErrorLog)
grdErrorLog.DataSource = _dstErrorLog.Tables(0)
End Sub
Private Sub grdErrorLog_UserDeletingRow(sender As Object, e As DataGridViewRowCancelEventArgs) Handles grdErrorLog.UserDeletingRow
_adapter.Update(_dstErrorLog.Tables(0))
End Sub
When I delete a row, it disappears from the DataGridView but when I re-open the form, the data is all still there. Do I need to specify the DeleteCommand myself? And if so, then what is the purpose of the SqlCommandBuilder??
Use the UserDeletedRow event, not the UserDeletingRow.
In the UserDeletingRow event the changes made to your DataGridView are still not committed to the DataSource binded, so calling the SqlDataAdapter.Update in that event doesn't result in any changes to the database because the table is still unchanged.
Private Sub grdErrorLog_UserDeletedRow(sender As Object, e As DataGridViewRowEventArgs) Handles grdErrorLog.UserDeletingRow
Dim count = _adapter.Update(_dstErrorLog.Tables(0))
Console.WriteLine("Rows deleted:" & Count)
End Sub
Infact in the UserDeletingRow the argument e is a DataGridViewRowCancelEventArgs meaning that you could still cancel the deletion setting e.Cancel = True
Related
I am trying to have a add, delete, and edit function in Vb.net by using one update button and changing the values in the datagridview manually then hitting update. However, I get an error stating
"System.InvalidOperationException: 'Update requires a valid UpdateCommand when passed DataRow collection with modified"
Any Ideas? The error comes next to the da.Update(changes)
Also in the above code not shown in my code I have load_data() in the private form1_load sub.
Here is code:
Dim da As New SqlDataAdapter
Dim dt As New DataSet
Private Sub Button1_Click_1(sender As Object, e As EventArgs) Handles Button1.Click
Dim cmd As New SqlCommandBuilder
Dim changes As New DataSet
changes = dt.GetChanges
If changes IsNot Nothing Then
da.Update(changes)
da.Fill(dt)
DataGridView1.DataSource = dt.Tables(0)
End If
End Sub
Private Sub load_data()
Using connection = New SqlConnection("Data Source=.\SQLEXPRESS;Initial Catalog=vbconnectionfinal;Integrated Security=True")
da = New SqlDataAdapter("Select * From TrueTrack", connection)
dt.Clear()
da.Fill(dt)
DataGridView1.DataSource = dt.Tables(0)
End Using
End Sub
You are creating a SqlCommandBuilder but not associating it with a SqlDataAdapter, so what's the point? The whole purpose of a command builder is to automatically generate action commands when you call Update on a data adapter. When you create your data adapter, create the command builder immediately after and associate the two, which you would do by passing the data adapter as an argument to the constructor of the command builder.
The following code works for me.
Dim da As New SqlDataAdapter
Dim dt As New DataSet
Dim connection = New SqlConnection("connection string")
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim cmd As New SqlCommandBuilder(da)
Dim changes As New DataSet
changes = dt.GetChanges
If changes IsNot Nothing Then
da.Update(changes)
DataGridView1.DataSource = dt.Tables(0)
End If
End Sub
Private Sub load_data()
Dim cmd As SqlCommand = New SqlCommand("Select * From TrueTrack", connection)
da = New SqlDataAdapter(cmd)
dt.Clear()
da.Fill(dt)
DataGridView1.DataSource = dt.Tables(0)
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
load_data()
End Sub
Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
connection.Close()
End Sub
I've linked an access database to my form.
I have 1 table , 2 rows
1 = Researchtype short text
2 = Researchdetails (long text)
In my combobox1 i've binded my researchtype row so i can choose a type of research.
Question now: how can i bind the details data to the richtextbox below it in order to show the research data as soon as i choose a research type?
I've tried if else combos, try catch combos,
i'm thinking i'm actually overthinking the issue here.
What would be the easiest way to "select from dropdown" and show the result in textbox.
I'm a vb.net beginner
Public Class Onderzoeken
Private Sub Onderzoeken_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'PatientenDatabaseDataSetX.tbl_OnderzoeksTypes' table. You can move, or remove it, as needed.
Me.Tbl_OnderzoeksTypesTableAdapter.Fill(Me.PatientenDatabaseDataSetX.tbl_OnderzoeksTypes)
End Sub
Private Sub cboxOnderzoek_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cboxOnderzoek.SelectedIndexChanged
If cboxOnderzoek.SelectedItem = Nothing Then
cboxOnderzoek.Text = ""
Else
rtbBeschrijvingOnderzoek.Text = CStr(CType(cboxOnderzoek.SelectedItem, DataRowView)("OZ_Onderzoeksbeschrijving"))
End If
End Sub
End Class
I added the entire code of that page now , it's not much, but as stated: I added the binding source and displaymember "researchtype" to the combobox.
So when i start the form, i can choose a type of research.
Now i need to show the description of the research in the richtextbox
In the Form.Load...
I have a function that returns a DataTable that contains columns called Name and Type. I bind the ComboBox to the DataTable and set the DisplayMember to "Name". Each Item in the ComboBox contains the entire DataRowView. I set the TextBox to the first row (dt(0)("Type")) Type column value so the correct information will be displayed for the initial selection.
I put the code to change the textbox display in ComboBox1.SelectionChangeCommitted because the other change events will produce a NRE since .SelectedItem has not yet been set when the form loads. The commited event will only occur when the user makes a selection.
First, cast the SelectedItem to its underlying type, DataRowView. Then you want the value of the Type column. This value is assigned to the text property of the textbox.
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim dt = LoadCoffeeTable()
ComboBox1.DataSource = dt
ComboBox1.DisplayMember = "Name"
TextBox1.Text = dt(0)("Type").ToString
End Sub
Private Sub ComboBox1_SelectionChangeCommitted(sender As Object, e As EventArgs) Handles ComboBox1.SelectionChangeCommitted
TextBox1.Text = DirectCast(ComboBox1.SelectedItem, DataRowView)("Type").ToString
End Sub
Just substitute Researchtype for Name and Researchdetails for Type.
After using 'OleDbDataAdapter' to fill the dataset, you can set 'DisplayMember' and 'ValueMember' for your ComboBox. Every time the index of your ComboBox changes, it's 'ValueMember' will be displayed in richtextbox.
Here's the code you can refer to.
Private dataset As DataSet = New DataSet()
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim connString As String = "your connection String"
Using con As OleDbConnection = New OleDbConnection(connString)
con.Open()
Dim cmd As OleDbCommand = New OleDbCommand()
cmd.Connection = con
cmd.CommandText = "SELECT Researchtype, Researchdetails FROM yourtable"
Dim adpt As OleDbDataAdapter = New OleDbDataAdapter(cmd)
adpt.Fill(dataset)
End Using
ComboBox1.DisplayMember = "Researchtype"
ComboBox1.ValueMember = "Researchdetails"
ComboBox1.DataSource = dataset.Tables(0)
End Sub
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
RichTextBox1.Text = ComboBox1.SelectedValue.ToString()
End Sub
Result of my test.
I made a Sub that will populate my combobox with loan descriptions. I want to get the loancode of the loandescription on selectedindexchanged without querying again the database. Is this possible? Or should I query the database to get the indicated loancode?
Private Sub LoanProducts()
Using cmd As New SqlClient.SqlCommand("SELECT loancode,loandescription FROM LoanProducts", gSQlConn)
Dim dt As New DataTable
Dim da As New SqlClient.SqlDataAdapter
dt.Clear()
da.SelectCommand = cmd
da.Fill(dt)
For Each row As DataRow In dt.Rows
CmbLoanAvail.Items.Add(row("loandescription"))
Next row
End Using
End Sub
Expected output:
Everytime the combobox index changed, the loancode of the selected loandescription will be displayed to a textbox.
Set DataTable to combobox .DataSource property and populate .ValueMember and .DisplayMember properties with corresponding column names.
Private Sub LoanProducts()
Dim query As String = "SELECT loancode, loandescription FROM LoanProducts"
Using command As New SqlCommand(query, gSQlConn)
Dim data As New DataTable
Dim adapter As New SqlClient.SqlDataAdapter With
{
.SelectCommand = cmd
}
adapter.Fill(data)
CmbLoanAvail.ValueMember = "loancode"
CmbLoanAvail.DisplayMember = "loandescription"
CmbLoanAvail.DataSource = data
End Using
End Sub
You can use SelectionChangeCommitted event to execute some action when user made a selection
Private Sub comboBox1_SelectionChangeCommitted(
ByVal sender As Object, ByVal e As EventArgs) Handles comboBox1.SelectionChangeCommitted
Dim combobox As ComboBox = DirectCast(sender, ComboBox)
Dim selectedCode As String = combobox.SelectedValue.ToString() // returns 'loancode'
End Sub
If you could get DB rows as strongly typed classes, you could make use of ItemSource, DisplayMember and ValueMember, which would solve your problem.
In case you presented, you can use SelectedIndex property of ComboBox. Also, you need to store resultset in some class field (preferably Pirvate one). See example code below:
Public Class Form4
Private _result As DataTable
Private Sub Form4_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim dt As New DataTable
dt.Columns.Add("col1")
dt.Columns.Add("col2")
dt.Rows.Add("val11", "val12")
dt.Rows.Add("val21", "val22")
' at this point, we got our result from DB
_result = dt
For Each row As DataRow In dt.Rows
ComboBox1.Items.Add(row("col1"))
Next
End Sub
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
Dim selectedIndex = ComboBox1.SelectedIndex
Dim selectedRow = _result(selectedIndex)
End Sub
End Class
Keep your database objects local to the method where they are used so you can ensure that they are closed and disposed. Note the comma at the end of the first Using line. This includes the command in the same Using block.
Set the DataSource, DisplayMember and ValueMember after the Using block so the user interface code doesn't run until the connection is disposed.
To get the loan code you simply access the SelectValue of the ComboBox.
Private Sub LoanProducts()
Dim dt As New DataTable
Using gSqlConn As New SqlConnection("Your connection string"),
cmd As New SqlClient.SqlCommand("SELECT loancode,loandescription FROM LoanProducts", gSqlConn)
gSqlConn.Open()
dt.Load(cmd.ExecuteReader)
End Using
ComboBox1.DataSource = dt
ComboBox1.DisplayMember = "loandescription"
ComboBox1.ValueMember = "loancode"
End Sub
Private Sub ComboBox1_SelectionChangeCommitted(ByVal sender As Object, ByVal e As EventArgs) Handles ComboBox1.SelectionChangeCommitted
MessageBox.Show($"The Loan Code is {ComboBox1.SelectedValue}")
End Sub
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.
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
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
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
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
I just found out about the CommandBuilder, and thought it sounded straight foward and easy to use. Clearly I'm still missing things. I've got a DataGridView that successfully updates dbSet table called Customers. But it's not updating to the actual database file:
...
Dim ConMain As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\dummy_data.accdb")
...
Private Sub CustomerDataGridView_RowValidated(ByVal sender As Object, _
ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) _
Handles CustomerDataGridView.RowValidated
Me.CustomersTableAdapter.Update(Me.Dummy_dataDataSet.Customers)
Dim CustomerAdapter As New OleDbDataAdapter("Select * From Customers", ConMain)
Dim ObjComander As New OleDbCommandBuilder(CustomerAdapter)
CustomerAdapter.Update(Dummy_dataDataSet, "Customers")
End Sub
It doesn't throw an error, and any changes I've made are kept in the memory (I can open and close the form and the changes will remain), but they are not actually written to the DB. What am I missing?
Try this
Dim ConMain As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\dummy_data.accdb")
Dim m_DtCustomer As New DataTable
Dim CustomerAdapter As OleDbDataAdapter
Dim m_Bsource As New BindingSource
'Populate the datagridview
Sub FillDataGrid()
CustomerAdapter = New OleDbDataAdapter("Select * From Customers", ConMain)
m_DtCustomer.Clear()
CustomerAdapter.Fill(m_DtCustomer)
m_Bs.DataSource = m_DtCustomer
CustomerDataGridView.Datasource = m_Bs
End Sub
'Update changes to the database
Sub UpdateDatabase()
Dim ObjComander As New OleDbCommandBuilder(CustomerAdapter)
CustomerAdapter.Update(m_DtCustomer)
End Sub
Private Sub CustomerDataGridView_RowValidated(ByVal sender As Object, _
ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) _
Handles CustomerDataGridView.RowValidated
Call Me.UpdateDatabase()
End Sub