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  1. #1
    SitePoint Wizard
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    the best way to know that a table isn't empty

    Hi,

    I'm looking for the most efficient way to know if a table isn't empty. So far, I just queried it, gathered the result and checked if it was empty or not.

    Is there a more efficient way to do it?

    Regards,

    -jj.

  2. #2
    SQL Consultant gold trophysilver trophybronze trophy
    r937's Avatar
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    SELECT COUNT(*) FROM daTable

    alternatively,

    SELECT acolumn FROM daTable LIMIT 1
    rudy.ca | @rudydotca
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  3. #3
    reads the ********* Crier silver trophybronze trophy longneck's Avatar
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    select count(*) from datable is best for myisam tables and can be horrible for innodb, but select acolumn from datable limit 1 is very good for myisam tables and best for innodb tables.

    so use the second form.
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  4. #4
    SitePoint Wizard webcosmo's Avatar
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    how about
    Code:
    select top 1 myColumn from myTable
    Is there any difference over cout(*)?

  5. #5
    SQL Consultant gold trophysilver trophybronze trophy
    r937's Avatar
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    yes, there is a difference

    also, TOP doesn't work in mysql

    rudy.ca | @rudydotca
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