Violation of UNIQUE KEY constraint 'UserName'. Cannot insert duplicate key in object 'dbo.Customers'

[teardropzerone]

Help! I set up my database in microsoft sql server 2005.<br />
I have this table named Customers<br />
Now i have this field Username<br />
then from modify tables I right click row Username<br />
and select Indexes/keys<br />
then I select add. select columns and select the field Username<br />
and change the Is Unique to Yes and Type to Unique KEy<br />
<br />
My Problem is in registration form of my website this message appears every time I enter username that is already existing in the database. Help me How will I fix it. I just need to know the codes in c# so that the if I enter the existing username it will not be accepted and there will be a message error that the username is already taken. Just like in signing up in yahoo. please help me.. Im using C#, microsoft web developer 2005 and microsoft sql server 2005 <br />
<br />

 

[Quandiraw]

You better post the error message. But try these things |)
check the sql statement in your c# code
check the table definition for duplicate keys (Primary, and additional constraint key), etc

 

[TheMadProfessor]

You need to trap the error returning from your database engine, most likely thru a Try...Catch block (or whatever the C# equivalent might be). Then check to see if SQL Server has tossed the duplicate key error and handle it appropriately. Any other error, toss it back as an unhandled error.