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Accepting Unique Values only: I manage to do it but is there a more elegant way?

Posted By:      Posted Date: September 30, 2010    Points: 0   Category :ASP.Net
 

Hi everyone,

I'll try to make this concise. Anyways, I'm trying to only allow unique data to my database. my database. What I did before adding the entry is to use a Search Query for the value of the txtbox

"SELECT IDnum WHERE IDnum = '" & txtID & "'"

Then compare it with that of the txtbox.

IF objReader("IDNum") <> txtID.textbox then add the entry Else Display a Warning.

in the above code, I can detect the when the user entered an existing value. however, If the user entered a NEW (unique) value an error is Raised "Invalid attempt to read when no data is present" I hit the wall with this.

So what I did, Since I can detect Duplicates and have errors when entering unique value, I used the ON ERROR GOTO statement: I did it like this.

On Error Goto errHandler

   If objReader("IDNum") = txtID.textbox then
     lbl1.text = "Existing Record"
     objReader.close()
     Exit Sub
   End IF

errHandler:

  'do the codes to add the entry

  Resume exitHERE



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