Home Forums SQL Server 2008 SQL Server 2008 - General How to slect data from table ? RE: How to slect data from table ?

  • December 26, 2014 at 1:53 pm

    #1766517

    serg-52 (12/26/2014)

    Jeff Moden (12/26/2014)

    serg-52 (12/26/2014)

    Try

    Select Phone1,Phone2 from tblregistration

    where 'abc@yahoo.com,def@yahoo.com,efg@yahoo.com' like '%'+Usernames+'%'

    That could end up being a pretty bad performance problem because it's not SARGable. Guaranteed , if I'm reading that correctly.

    It will, if the site will manage to attract millions of users. And being it the case it definitley will need a bit more sofisticated frontend which will be able to parse comma separated list before sending it to SQL. If number of users is under 50000 i see no big perfomance problems with table scan.

    Or until someone in a hurry runs across the code and uses it for something much bigger. 😉

    It just doesn't take that much longer to do it right the first time. If it's the second time, it takes no extra time to do it right. There just has to be a first time.

    --Jeff Moden

    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

    Change is inevitable... Change for the better is not.

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)