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(PHP 4 >= 4.1.0)

dbx_compare -- Compare two rows for sorting purposes


int dbx_compare ( array row_a, array row_b, string column_key [, int flags])

dbx_compare() returns 0 if the row_a[$column_key] is equal to row_b[$column_key], and 1 or -1 if the former is greater or is smaller than the latter one, respectively, or vice versa if the flag is set to DBX_CMP_DESC. dbx_compare() is a helper function for dbx_sort() to ease the make and use of the custom sorting function.

The flags can be set to specify comparison direction:

  • DBX_CMP_ASC - ascending order

  • DBX_CMP_DESC - descending order

and the preferred comparison type:

  • DBX_CMP_NATIVE - no type conversion

  • DBX_CMP_TEXT - compare items as strings

  • DBX_CMP_NUMBER - compare items numerically

One of the direction and one of the type constant can be combined with bitwise OR operator (|). The default value for the flags parameter is DBX_CMP_ASC | DBX_CMP_NATIVE.

Example 1. dbx_compare() example

function user_re_order ($a, $b) {
    $rv = dbx_compare ($a, $b, "parentid", DBX_CMP_DESC);
    if ( !$rv ) {
        $rv = dbx_compare ($a, $b, "id", DBX_CMP_NUMBER);
    return $rv;

$link   = dbx_connect (DBX_ODBC, "", "db", "username", "password")
    or die ("Could not connect");

$result = dbx_query ($link, "SELECT id, parentid, description FROM table ORDER BY id");
    // data in $result is now ordered by id

dbx_sort ($result, "user_re_order");
    // date in $result is now ordered by parentid (descending), then by id

dbx_close ($link);

See also dbx_sort().

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