以下是 UPDATE 命令修改 MySQL 数据表数据的通用 SQL 语法：
UPDATE table_name SET field1=new-value1, field2=new-value2
[WHERE Clause]
你可以同时更新一个或多个字段。
你可以在 WHERE 子句中指定任何条件。
你可以在一个单独表中同时更新数据。
mysql> select * from myroot;
+----+------+------+--------+------------+
| id | name | age | phone | date |
+----+------+------+--------+------------+
| 1 | kk | 12 | 232434 | 2022-12-03 |
| 2 | kkkk | 2234 | 2232 | 2033-02-01 |
+----+------+------+--------+------------+
2 rows in set (0.00 sec)
mysql> update myroot set age = 1;
Query OK, 2 rows affected (0.02 sec)
Rows matched: 2 Changed: 2 Warnings: 0
mysql> slect * from myroot;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'slect * from myroot' at line 1
mysql> select * from myroot;
+----+------+-----+--------+------------+
| id | name | age | phone | date |
+----+------+-----+--------+------------+
| 1 | kk | 1 | 232434 | 2022-12-03 |
| 2 | kkkk | 1 | 2232 | 2033-02-01 |
+----+------+-----+--------+------------+
2 rows in set (0.01 sec)
mysql> update myroot set age = 2 where phone = 232434;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from myroot;
+----+------+-----+--------+------------+
| id | name | age | phone | date |
+----+------+-----+--------+------------+
| 1 | kk | 2 | 232434 | 2022-12-03 |
| 2 | kkkk | 1 | 2232 | 2033-02-01 |
+----+------+-----+--------+------------+
2 rows in set (0.00 sec)