mysql> DROP TABLE IF EXISTS t1;

Query OK, 0 rows affected (0.00 sec)

mysql> CREATE TABLE t1 (t BLOB, n INT, UNIQUE (t));

Query OK, 0 rows affected (0.01 sec)

mysql> INSERT INTO t1 VALUES ('Hrecvx_0004ln-00',1), ('Hrecvx_0004mm-00',1);

Query OK, 2 rows affected (0.00 sec)

Records: 2  Duplicates: 0  Warnings: 0

mysql> SELECT * FROM t1;

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

| t                | n    |

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

| Hrecvx_0004ln-00 |    1 |

| Hrecvx_0004mm-00 |    1 |

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

2 rows in set (0.00 sec)

mysql> INSERT INTO t1 VALUES ('Hrecvx_0004mm-00',2) ON DUPLICATE KEY UPDATE n = VALUES (n);

Query OK, 2 rows affected (0.00 sec)

mysql> SELECT * FROM t1;

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

| t                | n    |

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

| Hrecvx_0004ln-00 |    2 |

| Hrecvx_0004mm-00 |    1 |

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

2 rows in set (0.00 sec)