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)
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