php教程

dbx_compare

(PHP 4 >= 4.1.0, PHP 5 < 5.1.0, PECL dbx >= 1.1.0)

dbx_compareCompare two rows for sorting purposes

说明

dbx_compare ( array $row_a , array $row_b , string $column_key [, int $flags = DBX_CMP_ASC | DBX_CMP_NATIVE ] ) : int

dbx_compare() is a helper function for dbx_sort() to ease the make and use of the custom sorting function.

参数

row_a

First row

row_b

Second row

column_key

The compared column

flags

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 (|).

返回值

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.

范例

Example #1 dbx_compare() example

<?php
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);
?>

参见

  • dbx_sort() - Sort a result from a dbx_query by a custom sort function

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