ExecuteNonQuery: Connection property has not been initialized.

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1.00/5 (2 votes)

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Sub Tampildata()
Dim ds = New DataSet
Dim cn As New SqlConnection("Data Source=PRITHVI;Initial Catalog=Database2;Integrated Security=True")
Dim query As String
query = "select * from Dish"
Dim da = New SqlDataAdapter(query, cn)
da.Fill(ds)
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim Cmd = New SqlCommand
Dim cn As New SqlConnection("Data Source=PRITHVI;Initial Catalog=Database2;Integrated Security=True")
Dim query As String
query = "Update Dish set Nameofdish='" & Txtname.Text & "',Typeofdish='" & TxtType.Text & "',Price='" & Txtprice.Text & "' where Dishid='" & ComboBox1.Text & "' "
Cmd.CommandText = query
Cmd.ExecuteNonQuery()
MsgBox("Updated")
Tampildata()

End Sub

Posted 17-Dec-15 8:08am

Member 12214252

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Member 12214252 17-Dec-15 14:09pm

im trying to insert values in to my database . any corrections or alternative coding is welcome

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OriginalGriff · Accepted Answer · 2015-12-17T08:42:00

Three things:
1) Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead.
2) It's a damn good idea to store connections strings in a configuration file, so they only need to be changed in one place, and your app doesn't need to be recompiled...
3) Your Button1 Click handler doesn't use the connection object "cn" it cretaed - so you get the error. Try creating the CMD object after the Connection:

VB

Dim cn As New SqlConnection("Data Source=PRITHVI;Initial Catalog=Database2;Integrated Security=True")
cn.Open();
Dim Cmd = New SqlCommand(query, cn);