请教1个关于delete语句的小问题。

[edgethinking]

我用的版本是mySql6.0, 执行下面语句的时候，
delete from t_bd_goodsshopinfo where fid in (select fid from t_bd_goods)

报错：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. 0.000 sec

可是我执行 delete from t_bd_goodsshopinfo where fid in (1, 2)却是可以的。请问1下，这个是什么原因呢？ 多谢了！

[ACMAIN_CHM]

You are using safe update mode 您在使用安全更新模式。

[edgethinking]

引用 1 楼 ACMAIN_CHM 的回复:

You are using safe update mode 您在使用安全更新模式。

那怎么改变安全更新模式呢？

[edgethinking]

可以了，非常感谢。