MySQL更新UPDATA的使用

语法：UPDATE 表名 SET 列名=值 [WHERE 条件语句];

mysql> SELECT * FROM student_info;
+------+---------+
| age  | name    |
+------+---------+
|   12 | Lili    |
|   27 | Jack    |
|   25 | Rose    |
|   25 | Ann     |
|   26 | Mark    |
|   68 | Bill    |
|   16 | James   |
|   20 | Fred    |
|    8 | Gary    |
|   22 | Martin  |
|   35 | Charles |
|   31 | Joseph  |
|   49 | Henry   |
|   57 | Mike    |
| NULL | Bob     |
+------+---------+
15 rows in set (0.00 sec)

mysql>

# 将所有age都置0

mysql> UPDATE student_info SET age=0;
Query OK, 15 rows affected (0.04 sec)
Rows matched: 15  Changed: 15  Warnings: 0

mysql> SELECT * FROM student_info;
+------+---------+
| age  | name    |
+------+---------+
|    0 | Lili    |
|    0 | Jack    |
|    0 | Rose    |
|    0 | Ann     |
|    0 | Mark    |
|    0 | Bill    |
|    0 | James   |
|    0 | Fred    |
|    0 | Gary    |
|    0 | Martin  |
|    0 | Charles |
|    0 | Joseph  |
|    0 | Henry   |
|    0 | Mike    |
|    0 | Bob     |
+------+---------+
15 rows in set (0.00 sec)

mysql>

# 将名为Rose的年龄改为26

mysql> UPDATE student_info SET age=26 WHERE name='Rose';
Query OK, 1 row affected (0.02 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> SELECT * FROM student_info;
+------+---------+
| age  | name    |
+------+---------+
|    0 | Lili    |
|    0 | Jack    |
|   26 | Rose    |
|    0 | Ann     |
|    0 | Mark    |
|    0 | Bill    |
|    0 | James   |
|    0 | Fred    |
|    0 | Gary    |
|    0 | Martin  |
|    0 | Charles |
|    0 | Joseph  |
|    0 | Henry   |
|    0 | Mike    |
|    0 | Bob     |
+------+---------+
15 rows in set (0.00 sec)

mysql>