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c#asp.netdatabaseerror-handlingif-statement
Scott Clarke
Scott Clarke

Reputation: 33

Checking if email address already exists in db

I'm trying to error handle a registration aspx/c# page on my application and want to run a check whether the email address that a user has tried to register already exists as the email address is used as a primary key in my database.

I have tried IF NOT EXISTS/IF EXISTS but these dont give the desired effect so was wondering if there was another way around it?

Look forward to your reply,

Scott

Upvotes: 0

Views: 2245

Answers (2)

iivel
iivel

Reputation: 2576

First answer certainly works, but a slightly more performant example would be:


select top 1 null from users where email = @email

on large or poorly-indexed tables.

Upvotes: 0

stefan
stefan

Reputation: 2886

select count(*) from users where email = @email

(int)executescalar > 0 == dupe

Upvotes: 4

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