Question

I am new to VB.net and creating an application so that user needs login username and password.

I am using a SQL Server Compact Edition database.

This is my code which works perfect:-

Imports System.Data.SqlClient
Imports System.Data.SqlServerCe

Public Class frm_edit_patient
    Dim con As New SqlCeConnection
    Try
        Dim SQLquery As String
        Dim da As SqlCeDataAdapter
        Dim ds As New DataSet
        Dim myConString As String = My.Settings.Database1ConnectionString
        con.ConnectionString = myConString
        MsgBox("Database is now open")
        MessageBox.Show("connected")
    Catch ex As Exception
        MessageBox.Show(ex.ToString)
    End Try
End Sub

The above code works fine and shows me connected

However when I add this piece of code

        SQLquery = "SELECT id FROM user where username=John Doe"
        da = New SqlCeDataAdapter(SQLquery, con)
        da = New SqlCeDataAdapter(SQLquery, con)
        da.Fill(ds, "db1")

It gives me this exception error:-

What does it mean? how to get the userid of that particular person?

Also if i just put the insert query in SQLquery, will it work? As i have been doing this by watching few video tutorials, but further they don’t have tutorials on this, also my book does not explains anything about Compact databases and as i am so far with this application dont want to switch…

Answer 1

Put your username between single quotes and user is a reserved word in Sql Compact.
You need to enclose it in square brackets

SQLquery = "SELECT id FROM [user] where username='John Doe'"