请大家把这个sql语句帮小弟我解读一上上哈，多谢哦

请大家把这个sql语句帮我解读一下下哈，谢谢哦~
update item ii INNER JOIN lineitem on ii.id=lineitem.itemId set ii.sti=ii.sti+(select SUM(ll.quantity) from lineitem ll where ll.status=3 and ll.itemId=ii.id group by ii.id ) where lineitem.status=3


哪位好心人帮我解读下，这个SQL语句，非常感谢哦~；

我对SQL语句，只是略懂皮毛而已。

THANKS~!

[解决办法]

SQL code

update item ii INNER JOIN lineitem on ii.id=lineitem.itemId set ii.sti=ii.sti+(select SUM(ll.quantity) from lineitem ll where ll.status=3 and ll.itemId=ii.id group by ii.id ) where lineitem.status=3
[解决办法]
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引用:

SQL code

update item ii INNER JOIN lineitem on ii.id=lineitem.itemId set ii.sti=ii.sti+(select SUM(ll.quantity) from lineitem ll where ll.status=3 and ll.itemId=ii.id group by ii.i……

[解决办法]
SQL code
UPDATE ii SET ii.id=ii.id+SUM(li.quantity) FROM item  ii INNER JOIN lineitem li ON li.itemId=ii.idWHERE li.status=3  GROUP BY li.itemid,ii.id