mysql> DROP TABLE IF EXISTS myupdate;
Query OK, 0 rows affected, 1 warning (0.05 sec)
mysql> CREATE TABLE `myupdate` (
-> `myval` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
-> `myupdate` timestamp NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP
-> ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
Query OK, 0 rows affected (0.17 sec)
mysql> INSERT INTO `myupdate` (`myval`)
-> VALUES
-> ('-- 12 --' ),
-> ('-- 13 --' ),
-> ('-- 14 --' ),
-> ('-- 25 --' );
Query OK, 4 rows affected (0.02 sec)
Records: 4 Duplicates: 0 Warnings: 0
mysql> SHOW STATUS LIKE 'Handler_update';
+----------------+-------+
| Variable_name | Value |
+----------------+-------+
| Handler_update | 12 |
+----------------+-------+
1 row in set (0.12 sec)
mysql> UPDATE myupdate set myval = REPLACE(myval,'1','9');
Query OK, 3 rows affected (0.00 sec)
Rows matched: 4 Changed: 3 Warnings: 0
mysql> SHOW STATUS LIKE 'Handler_update';
+----------------+-------+
| Variable_name | Value |
+----------------+-------+
| Handler_update | 15 |
+----------------+-------+
1 row in set (0.01 sec)
mysql> SELECT * FROM myupdate;
+----------+---------------------+
| myval | myupdate |
+----------+---------------------+
| -- 92 -- | 2023-08-10 07:58:42 |
| -- 93 -- | 2023-08-10 07:58:42 |
| -- 94 -- | 2023-08-10 07:58:42 |
| -- 25 -- | NULL |
+----------+---------------------+
4 rows in set (0.00 sec)
mysql> UPDATE myupdate set myval = REPLACE(myval,'2','8');
Query OK, 2 rows affected (0.00 sec)
Rows matched: 4 Changed: 2 Warnings: 0
mysql> SHOW STATUS LIKE 'Handler_update';
+----------------+-------+
| Variable_name | Value |
+----------------+-------+
| Handler_update | 17 |
+----------------+-------+
1 row in set (0.00 sec)
mysql> SELECT * FROM myupdate;
+----------+---------------------+
| myval | myupdate |
+----------+---------------------+
| -- 98 -- | 2023-08-10 07:58:42 |
| -- 93 -- | 2023-08-10 07:58:42 |
| -- 94 -- | 2023-08-10 07:58:42 |
| -- 85 -- | 2023-08-10 07:58:42 |
+----------+---------------------+
4 rows in set (0.00 sec)
mysql>