删除mysql 的一个表的数据的时候报告如下错误：
mysql> delete from upload_p_w_picpaths;
ERROR 1175 (HY000): You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column
 
 
mysql> show variables like '%sql_safe%';
+------------------+-------+
| Variable_name    | Value |
+------------------+-------+
| sql_safe_updates | ON    |
+------------------+-------+
1 row in set (0.00 sec)
 
 
 
mysql> set sql_safe_updates=0;
 
Query OK, 0 rows affected (0.00 sec)
 
mysql> show variables like '%sql_safe%';
+------------------+-------+
| Variable_name    | Value |
+------------------+-------+
| sql_safe_updates | OFF   |
+------------------+-------+
1 row in set (0.00 sec)
 
mysql> delete from upload_p_w_picpaths;
Query OK, 505 rows affected (0.01 sec)
 
然后再启用safe mode 
mysql> set sql_safe_updates=1;