ใช้ UPDATE ร่วม DATE_ADD() เพื่อบวกช่วงเวลาให้ทุกแถว
ตัวอย่าง
mysql> create table DemoTable (
ClientId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
ClientProjectDueDate date
);
Query OK, 0 rows affected (1.19 sec)
mysql> insert into DemoTable(ClientProjectDueDate) values('2018-01-21'); Query OK, 1 row affected (0.20 sec)
mysql> insert into DemoTable(ClientProjectDueDate) values('2019-03-25'); Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable(ClientProjectDueDate) values('2013-11-01'); Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable(ClientProjectDueDate) values('2015-06-14'); Query OK, 1 row affected (0.23 sec)
ข้อมูลก่อน
mysql> select * from DemoTable;
+----------+----------------------+ | ClientId | ClientProjectDueDate | +----------+----------------------+ | 1 | 2018-01-21 | | 2 | 2019-03-25 | | 3 | 2013-11-01 | | 4 | 2015-06-14 | +----------+----------------------+
บวก 2 ปี ทุกแถว
mysql> update DemoTable set ClientProjectDueDate=date_add(ClientProjectDueDate, INTERVAL 2 YEAR); Query OK, 4 rows affected (0.71 sec)
ผลลัพธ์
mysql> select * from DemoTable;
+----------+----------------------+ | ClientId | ClientProjectDueDate | +----------+----------------------+ | 1 | 2020-01-21 | | 2 | 2021-03-25 | | 3 | 2015-11-01 | | 4 | 2017-06-14 | +----------+----------------------+
รองรับ INTERVAL: DAY, MONTH, YEAR, HOUR, MINUTE, SECOND และรวมกันได้