UPDATE categories 
SET display_order = CASE id 
WHEN 1 THEN 3 
WHEN 2 THEN 4 
WHEN 3 THEN 5 
END, 
title = CASE id 
WHEN 1 THEN ‘New Title 1‘ 
WHEN 2 THEN ‘New Title 2‘ 
WHEN 3 THEN ‘New Title 3‘ 
END 
WHERE id IN (1,2,3) 

$display_order = array( 
1 => 4, 
2 => 1, 
3 => 2, 
4 => 3, 
5 => 9, 
6 => 5, 
7 => 8, 
8 => 9 
); 
$ids = implode(‘,‘, array_keys($display_order)); 
$sql = "UPDATE categories SET display_order = CASE id "; 
foreach ($display_order as $id => $ordinal) { 
$sql .= sprintf("WHEN %d THEN %d ", $id, $ordinal); // 拼接SQL語句 
} 
$sql .= "END WHERE id IN ($ids)"; 
echo $sql; 
mysql_query($sql); 

一條sql語句update 多條記錄