Retrieve data from Db set by combobox and display to textbox

Question

This is my code

s2="SELECT Notes From A WHERE ATotalNo =" + ComboBox1.SelectedItem +"" 
Dim cmd As OleDbCommand=New OleDbCommand(s2,myConnection1) 
cmd.CommandText=s2 TextBox1.Text=Convert.ToInt32(cmd.ExecuteScalar()).ToString()

And I am getting following error:-

Erorr: Data type mismatch in criteria expression

Answer 1

Apply ToString() on SelectedItem and why to convert result set to integer, if you only want to show it in textbox?

Try this,

s2 = "SELECT Notes From A WHERE ATotalNo = "& ComboBox1.SelectedItem.ToString() &"" 

Dim cmd As OleDbCommand = New OleDbCommand(s2, myConnection1) 
cmd.CommandText = s2 
TextBox1.Text = "" & cmd.ExecuteScalar()

Here the resultset is concatenated with a empty string to make it as whole string.

If column ATotalNo is of type VARCHAR then decorate selectedItem value with single quotes. Like,

s2 = "SELECT Notes From A WHERE ATotalNo = '"& ComboBox1.SelectedItem.ToString() &"'" 

Hope it helps thanks.