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Adding Constraint - MySQL

I need to add a constraint in some columns that aren't a FK or PK. I've already looked for it in the doentation but I haven't found yet. A constraint like this: constraint DontPlayAgainstYourself hometeam <> awayteam -- wallace reis...

  1. #1

    Default Adding Constraint

    I need to add a constraint in some columns that aren't a FK or PK. I've
    already looked for it in the doentation but I haven't found yet.

    A constraint like this:

    constraint DontPlayAgainstYourself
    hometeam <> awayteam

    --
    wallace reis
    wallace reis Guest

  2. #2

    Default Re: Adding Constraint

    Hi,

    Column level constraints aren't supported by MySQL, yet (at least not
    directly), they are supposed to be implemented in MySQL 5.1, as far as I
    know.

    However, it's possible to use triggers to emulate column level constraints.

    Markus


    Markus Popp Guest

  3. #3

    Default Re: Adding Constraint

    wallace reis wrote:
    > I need to add a constraint in some columns that aren't a FK or PK. I've
    > already looked for it in the doentation but I haven't found yet.
    >
    > A constraint like this:
    >
    > constraint DontPlayAgainstYourself
    > hometeam <> awayteam
    >
    > --
    > wallace reis
    You can't add check constraints in MySQL (yet), but there are two
    workarounds for that.
    Here are two links to get ypu started.

    [url]http://www.livejournal.com/users/arjen_lentz/49881.html[/url]
    [url]http://gilfster.blogspot.com/2005/11/check-constraints-in-mysql-50.html[/url]

    ciao
    gmax

    --
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    Giuseppe Maxia Guest

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