如何在 MySQL 中获取表的主键?
mysqlmysqli database
要获取表的主键，可以使用 show 命令。语法如下 −
SHOW INDEX FROM yourDatebaseName.yourTableName WHERE Key_name = 'PRIMARY';
假设，我们有一个包含两个主键的表；其中一个是"Id"，另一个是"RollNum"。表的查询如下 −
mysql> create table TwoOrMorePrimary −> ( −> Id int, −> Name varchar(200), −> RollNum int −> , −> Primary key(Id,Age) −> ); Query OK, 0 rows affected (0.85 sec)
应用上述语法获取表的主键。查询如下−
mysql> SHOW INDEX FROM business.TwoOrMorePrimary −> WHERE Key_name = 'PRIMARY';
以下是输出 −
+------------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Visible | Expression | +------------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+ | twoormoreprimary | 0 | PRIMARY | 1 | Id | A | 0 | NULL | NULL | | BTREE | | | YES | NULL | | twoormoreprimary | 0 | PRIMARY | 2 | RollNum | A | 0 | NULL | NULL | | BTREE | | | YES | NULL | +------------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+ 2 rows in set (0.12 sec)
