Question

请参阅下面的DDL：

 create table Person (ID int, [Type] int)
 insert into Person values (1,1)
 insert into Person values (2,1)
 insert into Person values (3,2)
 insert into Person values (4,3)
 insert into Person values (5,4)
 insert into Person values (6,5)

我正在寻找这样的结果：

2 1 1 1 1

以下条件会生成此结果：

There are 2 persons with a type of 1 (The first column value is: 2)
There is 1 person with a type of 2 (The second column value is: 1)
There is 1 person with a type of 3 (The third column value is: 1)
There is 1 person with a type of 4 (The forth column value is: 1)
There is 1 person with a type of 5 (The fifth column value is: 1)

Answer 1

使用CASE与SUM种不同的类型

select sum(case when [Type] = 1 then 1 else 0 end),
       sum(case when [Type] = 2 then 1 else 0 end),
       sum(case when [Type] = 3 then 1 else 0 end),
       sum(case when [Type] = 4 then 1 else 0 end),
       sum(case when [Type] = 5 then 1 else 0 end)
from tablename

Answer 2

如果你想让info_message不那么通用，就像转换到它只有1个计数一样，我可以这样做，但这需要我认为不必要的案例逻辑。它取决于你。如果您想让我改变它，请告诉我。

DECLARE @Cnt_list VARCHAR(MAX) =
                                    (
                                    SELECT CAST(COUNT(*) AS VARCHAR(10)) + ' '
                                    FROM Person
                                    GROUP BY [Type]
                                    ORDER BY [Type]
                                    FOR XML PATH('')
                                    )
SELECT @Cnt_list as cnt_list

<强>结果：

cnt_list
----------
2 1 1 1 1

然后是第二部分：

SELECT 'There are ' + CAST(COUNT(*) AS VARCHAR(10)) + ' person(s) with a type of ' + CAST([type] AS VARCHAR(10)) + '(The first column value is: ' + CAST(COUNT(*) AS VARCHAR(10)) + ')' info_message
FROM Person
GROUP BY [Type]

<强>结果：

info_message
--------------------------------------------------------------------
There are 2 person(s) with a type of 1(The first column value is: 2)
There are 1 person(s) with a type of 2(The first column value is: 1)
There are 1 person(s) with a type of 3(The first column value is: 1)
There are 1 person(s) with a type of 4(The first column value is: 1)
There are 1 person(s) with a type of 5(The first column value is: 1)

用于生成列值的SQL语句

2 个答案: