in reply to SELECT COUNT and DBI: rows

You can't use the rows method on select statements, only on statements that modify the database. In those cases, for most DBDs $dbh->do($sql) returns the number of rows affected. In other words, you can't use rows to count the rows from a select statement. This is in perldoc DBI in some detail, under the ->rows method.

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Re: Re: SELECT COUNT and DBI: rows
by Cody Pendant (Prior) on Sep 28, 2003 at 23:46 UTC
    You can't use the rows method on select statements, only on statements that modify the database.

    OK, now I'm really confused. I do that all the time! I do a select, and use rows to check if it returned anything. Don't I? (Goes to check...) yes I do. I have code like this: 

    ## prepare some SELECT statement
$sth->execute() || die "Error: " . $dbh->errstr;
if( $sth->rows > 0 ){
 ## do some stuff
}

    [download]

    ($_='kkvvttuubbooppuuiiffssqqffssmmiibbddllffss')
 =~y~b-v~a-z~s;                             print

    [download]
[reply]
[d/l]
[select]
      OK, now I'm really confused. I do that all the time!

      It might work on whatever database you're using, but getting a row count back from a SELECT isn't portable.

[reply]

        I'm using DBI and MySQL. That's interesting to know. I guess I should keep reading this thread to see what the more portable way to do it is...


        ($_='kkvvttuubbooppuuiiffssqqffssmmiibbddllffss')
 =~y~b-v~a-z~s;                             print

        [download]
[reply]
[d/l]
Re: Re: SELECT COUNT and DBI: rows
by bart (Canon) on Sep 29, 2003 at 06:45 UTC
    You can't use the rows method on select statements
    Where on earth do you see the rows() method used? I don't. My browser can't find it.

    I have no idea why it doesn't work for the OP. It seems to be working for me.

[reply]
Re: Re: SELECT COUNT and DBI: rows
by Anonymous Monk on Sep 29, 2003 at 14:43 UTC
    Mea culpa: I don't know where I saw the rows method used either, but obviously that was some good **** I was smoking yesterday. Please ignore that post, and I'll go find more to share. :I
[reply]

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