How do I make an UPDATE while joining tables on SQ

问题:

I tried :

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

And:

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

Both works with MySQL, but those give me a syntax error in SQLite.

How can I make this UPDATE / JOIN works with SQLite version 3.5.9 ?

回答1:

You can\'t. SQLite doesn\'t support JOINs in UPDATE statements.

But, you can probably do this with a subquery instead:

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

Or something like that; it\'s not clear exactly what your schema is.

回答2:

You can also use REPLACE then you can use selection with joins. Like this:

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