如何在SQLite上连接表时进行更新？

Question

我试过了 :

UPDATE closure JOIN item ON ( item_id = id ) 
SET checked = 0 
WHERE ancestor_id = 1

和:

UPDATE closure, item 
SET checked = 0 
WHERE ancestor_id = 1 AND item_id = id

两者都适用于MySQL,但那些在SQLite中给我一个语法错误.

如何使这个UPDATE/JOIN与SQLite版本3.5.9一起使用？

Answer 1

你不能.SQLite 不支持UPDATE语句中的JOIN.

但是,您可以使用子查询来执行此操作:

UPDATE closure SET checked = 0 
WHERE item_id IN (SELECT id FROM item WHERE ancestor_id = 1);

或类似的东西; 目前还不清楚你的架构究竟是什么.

Answer 2

您也可以使用REPLACE,然后您可以使用连接选择.像这样:

REPLACE INTO clusure 
 SELECT sel.col1,sel.col2,....,sel.checked --checked should correspond to column that you want to change
FROM (
 SELECT *,0 as checked FROM closure LEFT JOIN item ON (item_id = id) 
 WHERE ancestor_id = 1) sel