Re: Usiing FOREACH to loop through Array

At 3:27 PM -0700 6/29/02, Brad Melendy wrote:

Hi All, I've stumped myself here. In a nutshell, I have a function that returns my array based on a SQL query and here's the code: -------------begin code------------------- function getCourses($UID) { global $link; $result = mysql_query( "SELECT C.CourseName FROM tblcourses C, tblusers U, tblEnrollment E WHERE C.ID = E.CourseID AND E.UserID = U.ID AND U.ID = $UID", $link ); if ( ! $result ) die ( "getRow fatal error: ".mysql_error() ); return mysql_fetch_array( $result ); } ------------end code ---------------- I call this from a PHP page with the following code: ------------begin code-------------- $myCourses = getCourses($session[id]); foreach ($myCourses as $value) { print "<br>$value"; } ------------end code--------------- Now, when I test the SQL from my function directly on the database, it returns just want I want it to return but it isn't working that way on my PHP page. For results where there is a single entry, I am getting the same entry TWICE and for records with more than a single entry I am getting ONLY the FIRST entry TWICE. Now I know my SQL code is correct (I am testing it against a MySQL database using MySQL-Front) so I suspect I'm doing something stupid in my foreach loop.

I think your problem lies in a misunderstanding of the mysql_fetch_array() function. It doesn't return the entire result set in an array - just one record at a time. You can fix this in one of two ways: (1) Loop though the entire result set in your function: function getCourses($UID)

    {
     global $link;

     $ResultSet = array();

     $result = mysql_query( "SELECT C.CourseName FROM tblcourses C, tblusers U,
      tblEnrollment E WHERE C.ID = E.CourseID AND E.UserID = U.ID AND U.ID =
      $UID", $link );

     if ( ! $result )
      die ( "getRow fatal error: ".mysql_error() );

     while ($Row = mysql_fetch_array( $result ))
     {
      $ResultSet[] = $Row['C.CourseName'];
     }

     return $ResultSet;
    }

... $myCourses = getCourses($session[id]); foreach ($myCourses as $value)

    {
    print "<br>$value";
    }

or (2) set a flag in getCourses() so that the query is only executed once, otherwise returning a result line - something like: function getCourses($UID)

    global $link;
    static $result = false;

    if (!$result)
     {
       $result = mysql_query( "SELECT C.CourseName FROM tblcourses C, tblusers U,
        tblEnrollment E WHERE C.ID = E.CourseID AND E.UserID = U.ID AND U.ID =
        $UID", $link );
       if ( ! $result )
        die ( "getRow fatal error: ".mysql_error() );
     }
    {
    return mysql_fetch_array( $result );
    }

... while ($Row = getCourses($session[id]) as $value)

    {
    print "<br>", $Row['C.CourseName'];
    }

(standard caveats about off-top-of-head, untested code apply) The reason you are getting the first record TWICE is becaouse of the default behaviour of the mysql_fetch_array() function. It returns both an associative array - ie, elements of the form <field-name> => <value> - and a numerically indexed array (0, 1, 2, etc.). You can alter this behaviour by the second parameter of the function: see http://www.php.net/manual/en/function.mysql-fetch-array.php -steve

I'm hoping someone will spot my dumb mistake. Thanks very much for any help at all on this. ....Brad -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php

-- +------------------------------------------------------------------------+ | Steve Edberg sbedberg@ucdavis.edu | | University of California, Davis (530)754-9127 | | Programming/Database/SysAdmin http://pgfsun.ucdavis.edu/ | +------------------------------------------------------------------------+ | The end to politics as usual: | | The Monster Raving Loony Party (http://www.omrlp.com/) | +------------------------------------------------------------------------+