REPLACE INTO ... ON DUPLICATE KEY UPDATE

Question

我有一张桌子，上面有两个木偶的独特约束。

CREATE TABLE `targets` (
    `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT, 
    `client` SMALLINT(6) UNSIGNED NOT NULL, 
    -- some more fields here 
    `order_column` INT(10) NULL DEFAULT NULL, 
    PRIMARY KEY (`id`), 
    UNIQUE INDEX `client_order_column` (`client`, `order_column`) 
) 

，现在我想更新它的话，那order_column将包含增量整数，从0为每client值。我试图让这种方式：

replace into targets (
    `id`, 
    `client` , 
    `order_column` 
) 

(select  
    `id`, 
    `client` , 
    0 as order_column from targets 
    ) 
on duplicate key update 
    order_column = order_column + 1 

，但在最后一行越来越syntax error。我无法意识到，怎么了，请帮助我。

顺便说一句：有没有更好的方法来达到预期的效果？

Answer 1

INSERT INTO targets (id, client, order_column) 
SELECT a.id, a.client , 0 as order_column 
FROM targets a 
     ON DUPLICATE KEY 
     UPDATE order_column = a.order_column + 1 

• INSERT ... ON DUPLICATE KEY UPDATE Syntax