我的这个SQL Insert语句怎么了？

Question

I am trying to add a record to my table, however I'm getting an exception after it attempts to do so. I am able to open the connection successfully, (my first messagebox shows up) but after that I get the exception. Here's my code:

Private Sub btnUpdateInfo_Click(sender As Object, e As EventArgs) Handles btnUpdateInfo.Click
    Dim con As New SqlConnection
    Dim cmd As New SqlCommand
    con = New SqlConnection("Data Source=localhost\SQLEXPRESS;Initial Catalog=CISDB;Integrated Security=SSPI;")
    Try
        cmd.CommandText = "INSERT INTO customers (FirstName,LastName) VALUES (txtFirstName.Text, txtLastName.Text)"
        cmd.Connection = con
        con.Open()
        MsgBox("Connection Open ! ")
        cmd.ExecuteNonQuery()
        MsgBox("Record inserted")
        con.Close()
    Catch ex As Exception
        MsgBox("Error!")
    End Try
End Sub

Answer 1

For future readers - Sql parameters will save a lot of your and your coworkers time.

Private Sub btnUpdateInfo_Click(sender As Object, e As EventArgs) Handles btnUpdateInfo.Click
    Dim connString = "Data Source=localhost\SQLEXPRESS;Initial Catalog=CISDB;Integrated Security=SSPI;"
    Using connection As New SqlConnection(connString)
        Using command As New SqlCommand(connection)
            command.CommandText = "INSERT INTO customers (FirstName,LastName) VALUES (@FirstName, @Lastname)"
            Dim params As SqlParameter() =
            {
                New SqlParameter With { .ParameterName = "@FirstName", .SqlDbType.VarChar, .Value = txtFirstName.Text },
                New SqlParameter With { .ParameterName = "@LastName", .SqlDbType.VarChar, .Value = txtLastName.Text },
            }
            command.Parameters.AddRange(params)
            connection.Open() 
            command.ExecuteNonQuery()
            ' Inserted
        End Using
    End Using
End Sub 

Same for try.. catch (as @Plutonix has noticed in the comments) - if you will get "real" exception you will find reason and solution much faster

Answer 2

You need to look at the exception message (ex.Message) see what the issue is...If you have an error similar to multipart identifier then try this query string instead of your current query string for a quick test.

    cmd.CommandText = "INSERT INTO customers (FirstName,LastName) VALUES ('" & txtFirstName.Text & "', '" & txtLastName.Text & "')"

Check out parameterized query as previously indicated