仅更新 MySQL 字段中的 int


让我们先创建一个表 -

mysql> create table DemoTable702 (
   StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   StudentName varchar(100),
   StudentScore int
);
Query OK, 0 rows affected (0.56 sec)

使用 insert 命令在表中插入一些记录 -

mysql> insert into DemoTable702(StudentName,StudentScore) values('Chris',56);
Query OK, 1 row affected (0.19 sec)
mysql> insert into DemoTable702(StudentName,StudentScore) values('Robert',21);
Query OK, 1 row affected (0.21 sec)
mysql> insert into DemoTable702(StudentName,StudentScore) values('Mike',89);
Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable702(StudentName,StudentScore) values('David',99);
Query OK, 1 row affected (0.20 sec)

使用 select 语句显示表中的所有记录 -

mysql> select *from DemoTable702;

这将产生以下输出 -

+-----------+-------------+--------------+
| StudentId | StudentName | StudentScore |
+-----------+-------------+--------------+
| 1         | Chris       | 56           |
| 2         | Robert      | 21           |
| 3         | Mike        | 89           |
| 4         | David       | 99           |
+-----------+-------------+--------------+
4 rows in set (0.00 sec)

以下是更新 MySQL 中的 int 的查询 -

mysql> update DemoTable702 set StudentScore=StudentScore+9 where StudentId=2;
Query OK, 1 row affected (0.09 sec)
Rows matched: 1 Changed: 1 Warnings: 0

让我们再次检查表记录 -

mysql> select *from DemoTable702;

这将产生以下输出 -

+-----------+-------------+--------------+
| StudentId | StudentName | StudentScore |
+-----------+-------------+--------------+
| 1         | Chris       | 56           |
| 2         | Robert      | 30           |
| 3         | Mike        | 89           |
| 4         | David       | 99           |
+-----------+-------------+--------------+
4 rows in set (0.00 sec)

更新于:21-8-2019

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