如何用一个查询批量更新mysql数据？

Question

$query = mysql_query("UPDATE a SET fruit = '**apple**' WHERE id = '**1**' ");
$query2 = mysql_query("UPDATE a SET fruit = '**orange**' WHERE id = '**2**' ");
$query3 = mysql_query("UPDATE a SET fruit = '**peach**' WHERE id = '**3**' ");

有没有办法将其简化为一个查询？

Answer 1

我找到了以下解决方案:

INSERT into `table` (id,fruit)
    VALUES (1,'apple'), (2,'orange'), (3,'peach')
    ON DUPLICATE KEY UPDATE fruit = VALUES(fruit);

Id必须是唯一或主键.但不了解表现.

Answer 2

是的,您可以使用此查询执行此操作:

UPDATE a 
SET fruit = (CASE id WHEN 1 THEN 'apple'
                     WHEN 2 THEN 'orange'
                     WHEN 3 THEN 'peach'
             END)
WHERE id IN(1,2 ,3);