Solved

How can I make a recursive query?

Posted on 2008-06-11
3
298 Views
Last Modified: 2013-11-26
Hello everybody,

I finally could populate a combobox in VB.NET with data grabbed from a remote MySQL DB. The problem is that that data, only fills the combobox but doesn't store the query results in an array or anything. What I need to do now, is to validate the selected user with the DB, while making the password MD5 hashed. This MD5 encrypt is easy, but I don't know why I can't make the second query to fetch the password for the selected user in the combobox (making a last name, first name comparation).

Here's my code:
Private Sub comUsername_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles comUsername.TextChanged
        If comUsername.Text <> "" Then
            txtPassword.Enabled = True
            Dim user_full_name As String
 
            user_full_name = comUsername.Text
 
            SQL2 = "SELECT user_id FROM users WHERE 'user_last_name, user_name' = @user_full_name"
            myCommand.Connection = conn
            myCommand.CommandText = SQL2
 
            myAdapter.SelectCommand = myCommand
            myAdapter.Fill(myData)
 
            oReader = myCommand.ExecuteReader
 
            selected_user_id = oReader("user_id")
 
            MsgBox(selected_user_id)
 
            oReader.Close()
 
        Else
            txtPassword.Text = ""
            txtPassword.Enabled = False
        End If
    End Sub

Open in new window

0
Comment
Question by:Caracena
  • 2
3 Comments
 
LVL 142

Accepted Solution

by:
Guy Hengel [angelIII / a3] earned 250 total points
ID: 21771342
>            SQL2 = "SELECT user_id FROM users WHERE 'user_last_name, user_name' = @user_full_name"

you might look for the CONCAT function:
            SQL2 = "SELECT user_id FROM users WHERE CONCAT(user_last_name, ' ' , user_name) = @user_full_name"

assuming lastname and username as separated by a space.
0
 
LVL 6

Author Comment

by:Caracena
ID: 21771398
Thanks! It was that. it also had a comma (plus space). Another thing that I found is how to propperly place the variable in the SELECT statement:

SQL2 = "SELECT * FROM users WHERE concat(user_last_name,', ',user_name) = '" & comUsername.Text & "'"

Thanks agian!
0
 
LVL 142

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 21771446
>Another thing that I found is how to propperly place the variable in the SELECT statement:
using that method is NOT properly done.
use either the MySqlParameter, or at least handle the single quote "issue":

SQL2 = "SELECT * FROM users WHERE concat(user_last_name,', ',user_name) = '" & comUsername.Text.Replace("'", "''") & "'"

using the MySqlParameter:
http://dotnetnuke.adefwebserver.com/MySQL/MySql5sample/tabid/289/Default.aspx
0

Featured Post

3 Use Cases for Connected Systems

Our Dev teams are like yours. They’re continually cranking out code for new features/bugs fixes, testing, deploying, testing some more, responding to production monitoring events and more. It’s complex. So, we thought you’d like to see what’s working for us.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Creating an analog clock UserControl seems fairly straight forward.  It is, after all, essentially just a circle with several lines in it!  Two common approaches for rendering an analog clock typically involve either manually calculating points with…
More often than not, we developers are confronted with a need: a need to make some kind of magic happen via code. Whether it is for a client, for the boss, or for our own personal projects, the need must be satisfied. Most of the time, the Framework…
Internet Business Fax to Email Made Easy - With eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, fr…
In a recent question (https://www.experts-exchange.com/questions/28997919/Pagination-in-Adobe-Acrobat.html) here at Experts Exchange, a member asked how to add page numbers to a PDF file using Adobe Acrobat XI Pro. This short video Micro Tutorial sh…

816 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

9 Experts available now in Live!

Get 1:1 Help Now