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MySQL中添加新列并根据的IF条件设置值

2024-05-20 04:44:08 333

要基于条件设置值，请使用IF()方法。让我们首先创建一个表-

create table DemoTable
   -> (
   -> Age int
   -> );

使用插入命令在表中插入一些记录-

insert into DemoTable values(19);

insert into DemoTable values(16);

insert into DemoTable values(17);

insert into DemoTable values(22);

使用select语句显示表中的所有记录-

select *from DemoTable;

输出结果

这将产生以下输出-

+------+
| Age  |
+------+
|   19 |
|   16 |
|   17 |
|   22 |
+------+
4 rows in set (0.00 sec)

以下是根据条件设置值的查询-

select Age,if(Age > 18,'You are qualified!','Sorry, you are rejected!') AS Result from
DemoTable;

输出结果

这将产生以下输出-

+------+-------------------------+
| Age  | Result                  |
+------+-------------------------+
|   19 | You are qualified!      |
|   16 | Sorry, you are rejected!|
|   17 | Sorry, you are rejected!|
|   22 | You are qualified!      |
+------+-------------------------+
4 rows in set (0.00 sec)

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MySQL中添加新列并根据的IF条件设置值

输出结果

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