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Thread: constraints

  1. #1
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    Unanswered: constraints

    what is constraint? when do we need to constraint? please explain, thanks in advanced.

  2. #2
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    what is google?
    when do we need to use it?
    how do we use it?
    Let me google that for you
    I'd rather be riding on the Tiger 800 or the Norton

  3. #3
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    Apr 2011
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    Quote Originally Posted by healdem View Post
    what is google?
    when do we need to use it?
    how do we use it?
    Let me google that for you
    what is the use of dbforums.com then?
    when do we need to use dbforums.com?
    thanks

  4. #4
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    Quote Originally Posted by raindropz View Post
    what is the use of dbforums.com then?
    when do we need to use dbforums.com?
    When you have a specific problem (e.g. a SQL statement or a design question) that you cannot solve by reading the manual.

  5. #5
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    I don't understand the manual, isn't my question specific? thanks.

  6. #6
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    Quote Originally Posted by raindropz View Post
    isn't my question specific?
    no, not really

    here, let me answer it with exactly the same amount of specificity as your question --

    a constraint is a restriction on the data that will be accepted by the database

    when do we need to constrain? when we want the database to enforce a restriction on the data

    happy now?
    rudy.ca | @rudydotca
    Buy my SitePoint book: Simply SQL

  7. #7
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    Quote Originally Posted by r937 View Post
    when we want the database to enforce a restriction on the data
    Would we ever want the database to not enforce the restriction?

  8. #8
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    Quote Originally Posted by r937 View Post
    no, not really

    here, let me answer it with exactly the same amount of specificity as your question --

    a constraint is a restriction on the data that will be accepted by the database

    when do we need to constrain? when we want the database to enforce a restriction on the data

    happy now?
    can you please give examples? thanks.

  9. #9
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    Quote Originally Posted by raindropz View Post
    can you please give examples? thanks.
    lots of them right here --> database constraint examples
    rudy.ca | @rudydotca
    Buy my SitePoint book: Simply SQL

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