Question

假设我们有表：

+----------+------------+
| order_id | order_type |
+----------+------------+
| 1        | classsic   |
+----------+------------+
| 2        | classic    |
+----------+------------+
| 3        | urgent     |
+----------+------------+
| 4        | urgent     |
+----------+------------+
| 5        | canceled   |
+----------+------------+
| 6        | canceled   |
+----------+------------+
| 7        | classic    |
+----------+------------+

并要求获取所有订单的总数以及每个order_type的订单数。

返回的结果应该类似于：

+-------+---------+--------+----------+
| total | classic | urgent | canceled |
+-------+---------+--------+----------+
| 7     | 3       | 2      | 2        |
+-------+---------+--------+----------+

哪个sql语句会得到我们上面的结果？

Answer 1

使用条件聚合

select count(*) total,
       count(case when order_type = 'classic' then 1 end) classic,           
       count(case when order_type = 'urgent ' then 1 end) urgent ,
       count(case when order_type = 'canceled ' then 1 end) canceled 
from your_table

Answer 2

这将执行所需的输出。有关PIVOT运营商here

的更多信息

declare @tbl as table(
    order_id int
    ,order_type varchar(15)
)


insert into @tbl values (1, 'classic')
insert into @tbl values (2, 'classic')
insert into @tbl values (3, 'urgent')
insert into @tbl values (4, 'urgent')
insert into @tbl values (5, 'canceled')
insert into @tbl values (6, 'canceled')
insert into @tbl values (7, 'classic')


SELECT
    classic + urgent + canceled AS Total
    ,classic
    ,urgent
    ,canceled
FROM (
    SELECT order_id, order_type from @tbl   
) tbl
PIVOT(
    COUNT(order_id) FOR order_type IN (classic, urgent, canceled)
) pvt

Answer 3

如果您不想Case或Dynamic，请使用Pivot表达式的另一种方法：

SELECT COUNT(*) total,
       SUM(CASE
               WHEN order_type = 'classic'
                    OR order_type = 'classsic'
               THEN 1
               ELSE 0
           END) classic,
       SUM(CASE
               WHEN order_type = ' urgent '
               THEN 1
               ELSE 0
           END) urgent,
       SUM(CASE
               WHEN order_type = 'canceled'
               THEN 1
               ELSE 0
           END) canceled
FROM <table_name>;

结果：

+-------+---------+--------+----------+
| total | classic | urgent | canceled |
+-------+---------+--------+----------+
| 7     | 3       | 2      | 2        |
+-------+---------+--------+----------+

如何根据表中另一列的不同值获取行的总数和计数

3 个答案: