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>