Home Forums SQL Server 2005 T-SQL (SS2K5) Rand() function error RE: Rand() function error

  • March 2, 2009 at 5:46 pm

    #952183

    john.arnott (3/2/2009)

    So what's wrong with RAND(), you may be wondering? As Jeff notes, the RAND (and also the NEWID) functions are deliberately designed to be invoked a single time in a call, even if referenced multiple times. In SQL 2000, each reference produced a different result as the function would be evaluated again for each reference. This was a deliberate design decision at Microsoft.

    An interesting discussion on this topic was posted by Itzik Ben-Gan at http://www.sqlmag.com/Article/ArticleID/97032/sql_server_97032.html

    Ah... but that's not true for NEWID() which will give you a different return for every row generated by a SELECT. The code I provided above is proof of that.

    --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.

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