MySQL更新時Error Code:1093和Error Code:1175的解決辦法

Error Code: 1093. You can't specify target table 'ws_product' for update in FROM clause

這個是我們在使用update或者delete語句時，在where條件裡面加入的子查詢導緻的。例如如下的update語句：

update table set type = 'static' where id in (

select id from ws_product where first_name ='superman'

);

修改上述語句為下面這樣，該問題可以解決：

update ws_product set type = 'static' where id in (

select id form (

 select id from ws_product where first_name ='superman'

) xx

);

注意，這樣一定要給最裡面的子查詢定義一個别名，不然會報另外一個錯誤：

Error Code: 1248. Every derived table must have its own alias

Error Code: 1175. You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column To disable safe mode, toggle the option in Preferences -> SQL Queries and reconnect.

解決辦法是在目前session下執行如下的語句

SET SQL_SAFE_UPDATES = 0;

然後再執行Update語句