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根据MySQL中的条件对列求和

2024-05-17 14:59:04 394

让我们首先创建一个表-

mysql> create table DemoTable
(
   CustomerId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   ProductAmount int,
   CustomerCountryName varchar(10)
);

使用插入命令在表中插入一些记录-

mysql> insert into DemoTable(ProductAmount,CustomerCountryName) values(190,'US');
mysql> insert into DemoTable(ProductAmount,CustomerCountryName) values(200,'UK');
mysql> insert into DemoTable(ProductAmount,CustomerCountryName) values(1500,'AUS');
mysql> insert into DemoTable(ProductAmount,CustomerCountryName) values(2010,'US');
mysql> insert into DemoTable(ProductAmount,CustomerCountryName) values(7890,'UK');
mysql> insert into DemoTable(ProductAmount,CustomerCountryName) values(500,'US');

使用select语句显示表中的所有记录-

mysql> select *from DemoTable;

这将产生以下输出-

+------------+---------------+---------------------+
| CustomerId | ProductAmount | CustomerCountryName |
+------------+---------------+---------------------+
|          1 |           190 | US                  |
|          2 |           200 | UK                  |
|          3 |          1500 | AUS                 |
|          4 |          2010 | US                  |  
|          5 |          7890 | UK                  |
|          6 |           500 | US                  |
+------------+---------------+---------------------+
6 rows in set (0.00 sec)

以下是根据条件求和一列的查询。在这里，您想要汇总具有“US”国家/地区的客户的记录-

mysql> select SUM(ProductAmount) AS Total_Amount from DemoTable where CustomerCountryName='US';

这将产生以下输出-

+--------------+
| Total_Amount |
+--------------+
|         2700 |
+--------------+
1 row in set (0.00 sec)

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根据MySQL中的条件对列求和

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