MySQL 如何根据特定月份记录对选定的列值求和

首先让我们创建一张表 –

mysql> create table DemoTable
(
   Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   PurchaseDate date,
   SalePrice int
);
Query OK, 0 rows affected (0.51 sec)

使用插入命令在表中插入一些记录 –

mysql> insert into DemoTable(PurchaseDate,SalePrice) values('2018-01-10',450);
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable(PurchaseDate,SalePrice) values('2019-12-25',1000);
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable(PurchaseDate,SalePrice) values('2016-12-02',5560);
Query OK, 1 row affected (0.07 sec)
mysql> insert into DemoTable(PurchaseDate,SalePrice) values('2015-02-20',4550);
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable(PurchaseDate,SalePrice) values('2015-12-11',4110);
Query OK, 1 row affected (0.15 sec)

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 –

+----+--------------+-----------+
| Id | PurchaseDate | SalePrice |
+----+--------------+-----------+
|  1 | 2018-01-10   |     450   |
|  2 | 2019-12-25   |    1000   |
|  3 | 2016-12-02   |    5560   |
|   4 | 2015-02-20  |    4550   |
|  5 | 2015-12-11   |    4110   |
+----+--------------+-----------+
5 rows in set (0.00 sec)

以下是在MySQL中根据特定月份记录对选定列中的值求和的查询。例如，在此处仅添加了PurchaseDate中12月的SalePrice –

mysql> select SUM(SalePrice) from DemoTable
   where month(PurchaseDate)=12;

上面的代码只添加了选择的月份，即12月的记录(SalePrice) –

2019-12-25
2016-12-02
2015-12-11

这将产生以下输出 –

+----------------+
| SUM(SalePrice) |
| 10670          |
+----------------+
1 row in set (0.00 sec)

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