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mysql查询类型转换
在mysql查询时最好不要发生类型转换,如把varchar转换成int
mysql> explain select * from user where name=1/G
//如果你确定name字段是整型就不要把它转化成字符串,不加单引号
*************************** 1. row *************************** id: 1 select_type: SIMPLE table: user type: ALLpossible_keys: index_name_password key: NULL key_len: NULL ref: NULL rows: 99727 Extra: Using where1 row in set (0.02 sec)mysql> explain select * from user where name='1'/G
//如果你确定name字段是字符串就不要把它转化成整型,加单引号
*************************** 1. row *************************** id: 1 select_type: SIMPLE table: user type: refpossible_keys: index_name_password key: index_name_password key_len: 111 ref: const rows: 1 Extra: Using where1 row in set (0.00 sec)
