DESC Table incorrectly shows some unique keys as primary.

MariaDB [test]> CREATE TABLE `B2C_S_USER` (

    ->   `ROW_ID` varchar(15) NOT NULL,

    ->   `LOGIN` varchar(50) NOT NULL,

    ->   `CDC_INSERT_TIME` datetime DEFAULT sysdate(),

    ->   `CDC_UPDATE_TIME` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp(),

    ->   `op_ts` datetime DEFAULT NULL,

    ->   UNIQUE KEY `B2C_S_USER_P1` (`ROW_ID`),

    ->   KEY `B2C_S_USER_M1` (`LOGIN`)

    -> ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

Query OK, 0 rows affected (0.042 sec)

MariaDB [test]> select

    ->     tbl.table_schema,

    ->     tbl.table_name

    -> from information_schema.tables tbl

    -> left join information_schema.key_column_usage as col

    -> on tbl.table_name = col.table_name

    ->    and col.constraint_schema = tbl.table_schema

    ->    and col.constraint_name = 'PRIMARY'

    -> where

    ->     tbl.table_schema <> 'information_schema'

    -> and tbl.table_schema <> 'performance_schema'

    -> and tbl.table_schema <> 'mysql'

    -> and col.constraint_name is NULL;

+--------------+------------+

| table_schema | table_name |

+--------------+------------+

| test         | B2C_S_USER |

+--------------+------------+

1 row in set (0.052 sec)

MariaDB [test]> desc B2C_S_USER;

+-----------------+-------------+------+-----+---------------------+-------------------------------+

| Field           | Type        | Null | Key | Default             | Extra                         |

+-----------------+-------------+------+-----+---------------------+-------------------------------+

| ROW_ID          | varchar(15) | NO   | PRI | NULL                |                               |

| LOGIN           | varchar(50) | NO   | MUL | NULL                |                               |

| CDC_INSERT_TIME | datetime    | YES  |     | sysdate()           |                               |

| CDC_UPDATE_TIME | timestamp   | NO   |     | current_timestamp() | on update current_timestamp() |

| op_ts           | datetime    | YES  |     | NULL                |                               |

+-----------------+-------------+------+-----+---------------------+-------------------------------+

5 rows in set (0.001 sec)