如何通过 MySQL EXPLAIN 语句获取有关表的特定列的信息?\EXPLAIN 语句?
mysqlmysqli database更新于 2024/3/8 12:29:00
众所周知，EXPLAIN 语句将提供整个表的信息/结构。借助 EXPLAIN 语句以及表名和列名，我们可以获取有关该列的信息。
语法
EXPLAIN table_name col_name;
示例 1
mysql> EXPLAIN employee ID; +-------+---------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------+---------+------+-----+---------+----------------+ | ID | int(11) | NO | PRI | NULL | auto_increment | +-------+---------+------+-----+---------+----------------+ 1 row in set (0.11 sec)
上述查询将给出有关名为"employee"的表的"ID"列的信息。
示例2
mysql> EXPLAIN employee name; +-------+-------------+------+-----+---------+---------+ | Field | Type | Null | Key | Default | Extra | +-------+-------------+------+-----+---------+---------+ | Name | varchar(20) | YES | | NULL | | +-------+-------------+------+-----+---------+---------+ 1 row in set (0.03 sec)
上述查询将给出有关名为"employee"的表的另一列"Name"的信息。
