比如:
UPDATE test.tb_vobile a set a.name = '111 ' WHERE a.id = (select max(id) id from test.tb_vobile)
報錯:
[SQL]UPDATE test.tb_vobile a set a.name = '111 ' WHERE a.id = (select max(id) id from test.tb_vobile) [Err] 1093 - You can't specify target table 'a' for update in FROM clause
以下可通過:
UPDATE test.tb_vobile a join (select max(id) id from test.tb_vobile) b on a.id = b.id set a.name = '123 '; 或 UPDATE test.tb_vobile a ,(select max(id) id from test.tb_vobile) b set a.name = '321 ' WHERE a.id = b.id ;
說明:
1、update 時,更新的表不能在set和where中用於子查詢;
2、update 時,可以對多個表進行更新(sqlserver不行);
如:update ta a,tb b set a.Bid=b.id ,b.Aid=a.id;
3、update 後面可以做任意的查詢,這個作用等同於from;