MySQL 带 IF 条件的求和查询?
mysqlmysqli database
Sum() 是 MySQL 中的聚合函数。您可以将求和查询与 if 条件一起使用。要了解带 if 条件的求和查询，让我们创建一个表。
创建表的查询 −
mysql> create table SumWithIfCondition −> ( −> ModeOfPayment varchar(100) −> , −> Amount int −> ); Query OK, 0 rows affected (1.60 sec)
使用 insert 命令在表中插入一些记录。 查询语句如下 −
mysql> insert into SumWithIfCondition values('Offline',10);
Query OK, 1 row affected (0.21 sec)
mysql> insert into SumWithIfCondition values('Online',100);
Query OK, 1 row affected (0.16 sec)
mysql> insert into SumWithIfCondition values('Offline',20);
Query OK, 1 row affected (0.13 sec)
mysql> insert into SumWithIfCondition values('Online',200);
Query OK, 1 row affected (0.16 sec)
mysql> insert into SumWithIfCondition values('Offline',30);
Query OK, 1 row affected (0.11 sec)
mysql> insert into SumWithIfCondition values('Online',300);
Query OK, 1 row affected (0.17 sec)
使用 select 语句显示表中的所有记录。查询如下 −
mysql> select *from SumWithIfCondition;
以下是输出 −
+---------------+--------+ | ModeOfPayment | Amount | +---------------+--------+ | Offline | 10 | | Online | 100 | | Offline | 20 | | Online | 200 | | Offline | 30 | | Online | 300 | +---------------+--------+ 6 rows in set (0.00 sec)
这是带有 if 条件的 sum 查询。
案例 1 - if 为在线支付方式
查询如下 −
mysql> select sum(if(ModeOfPayment = 'Online',Amount,0)) as TotalAmount from SumWithIfCondition;
以下是输出 −
+-------------+ | TotalAmount | +-------------+ | 600 | +-------------+ 1 row in set (0.00 sec)
案例 2- 如果采用线下付款方式
查询如下 −
mysql> select sum(if(ModeOfPayment = 'Offline',Amount,0)) as TotalAmount from SumWithIfCondition;
以下是输出 −
+-------------+ | TotalAmount | +-------------+ | 60 | +-------------+ 1 row in set (0.00 sec)
