sql server - T-SQL: checking for email format

Question

I have this scenario where I need data integrity in the physical database. For example, I have a variable of @email_address VARCHAR(200) and I want to check if the value of @email_address is of email format. Anyone has any idea how to check format in T-SQL?

Many thanks!

Answer 1

I tested the following query with many different wrong and valid email addresses. It should do the job.

IF (
     CHARINDEX(' ',LTRIM(RTRIM(@email_address))) = 0 
AND  LEFT(LTRIM(@email_address),1) <> '@' 
AND  RIGHT(RTRIM(@email_address),1) <> '.' 
AND  CHARINDEX('.',@email_address ,CHARINDEX('@',@email_address)) - CHARINDEX('@',@email_address ) > 1 
AND  LEN(LTRIM(RTRIM(@email_address ))) - LEN(REPLACE(LTRIM(RTRIM(@email_address)),'@','')) = 1 
AND  CHARINDEX('.',REVERSE(LTRIM(RTRIM(@email_address)))) >= 3 
AND  (CHARINDEX('.@',@email_address ) = 0 AND CHARINDEX('..',@email_address ) = 0)
)
   print 'valid email address'
ELSE
   print 'not valid'

It checks these conditions:

• No embedded spaces
• '@' can't be the first character of an email address
• '.' can't be the last character of an email address
• There must be a '.' somewhere after '@'
• the '@' sign is allowed
• Domain name should end with at least 2 character extension
• can't have patterns like '.@' and '..'