循环创建新列

Question

假设我有一个 SQL Server 表，它有 4 列 MonthEnd、Gender、Weight 和 Age。

现在，MonthEnd 从 201901 到 201912。

我有一个运行查询的过程，该查询会生成各种指标，例如每个月的总和（体重）和平均值（年龄）。

现在，我在创建该月的指标时设置了 where MonthEnd = 201901。

输出是一个包含 2 列和 2 行的表。 Column1 标头是 Metric，Column2 标头是 201901，然后 row1 column1 表示 Total_Weight，row1 column2 是 sum(weight) 函数生成的值。

同样，row2 column1 表示 Average_Age，row2 column2 是 Average(Age) 函数的结果。

我已经完成了上述操作。

然后，我必须在将 where 子句更改为 where MonthEnd = 201902 后重新运行代码，然后将相同的结构应用于结果。

我希望能够一步运行 201901 到 201912 并让输出反映 13 列，即 column1 仍然是具有标题“Metric”的度量，但接下来的 12 列将具有标题 201901 到 201912每个月的相应结果包含在标题下方。

T-SQL 可以做到这一点吗？我觉得我可以使用 Pivot 使用 1 个聚合函数来做到这一点，但我还没有弄清楚如何同时执行多个聚合函数。

-- THIS SECTION SETS UP THE DATA SET STARTING POINT ---------

IF OBJECT_ID('[dbo].[example]') IS NOT NULL DROP TABLE [dbo].[example]
GO

CREATE TABLE [dbo].[example]
(
MonthEnd INT NOT NULL,
Grade VARCHAR(50) NOT NULL,
Name VARCHAR(50) NOT NULL,
Amount INT NULL
)
GO

INSERT INTO [dbo].[example]
VALUES 
(201901, 'A', 'Josh', 100),
(201901, 'A', 'Joe', 50),
(201901, 'A', 'Jill', 150),
(201901, 'B', 'Julie', 150),
(201901, 'B', 'Jim', 350),
(201901, 'C', 'Jeff', 100),
(201901, 'C', 'Jack', 125),
(201901, 'C', 'Jillian', 150),
(201901, 'C', 'Jess', 175),
(201901, 'C', 'James', 450),
(201902, 'A', 'Josh', 95),
(201902, 'A', 'Jill', 105),
(201902, 'B', 'Julie', 125),
(201902, 'B', 'Jim', 325),
(201902, 'C', 'Jeff', 75),
(201902, 'C', 'Jack', 100),
(201902, 'C', 'Jillian', 125),
(201903, 'A', 'Josh', 50),
(201903, 'B', 'Julie', 75),
(201903, 'B', 'Jim', 300),
(201903, 'C', 'Jeff', 50),
(201903, 'C', 'Jack', 50);

select * from [dbo].[example]

-- THE BELOW SECTION GENERATES THE DESIRED RESULTS WHICH I'D LIKE TO ACHIEVE THROUGH A PIVOT OR LOOP ---
-- I HAVE MONTHS FROM 201801 through 202103, SO I'D LIKE TO ITERATE THROUGH THEM AND PRODUCE THE DESIRED RESULT SET PROGRAMMATICALLY ---

IF OBJECT_ID('tempdb..#temp1') IS NOT NULL drop table #temp1
IF OBJECT_ID('tempdb..#temp2') IS NOT NULL drop table #temp2
IF OBJECT_ID('tempdb..#temp3') IS NOT NULL drop table #temp3

select 
    cast(Grade as varchar(max)) as Grade
    ,cast(Name as varchar(max)) as Name
    ,'SUM' as Metric
    ,cast(sum(Amount) as varchar(max)) as '201901'
into #temp1
from [dbo].[example] 
where MonthEnd = '201901'
group by 
    cast(Grade as varchar(max))
    ,cast(Name as varchar(max))

    union all

select 
    cast(Grade as varchar(max)) as Grade
    ,cast(Name as varchar(max)) as Name
    ,'AVG' as Metric
    ,cast(avg(Amount) as varchar(max)) as '201901'
from [dbo].[example] 
where MonthEnd = '201901'
group by 
    cast(Grade as varchar(max))
    ,cast(Name as varchar(max))


select 
    cast(Grade as varchar(max)) as Grade
    ,cast(Name as varchar(max)) as Name
    ,'SUM' as Metric
    ,cast(sum(Amount) as varchar(max)) as '201902'
into #temp2
from [dbo].[example] 
where MonthEnd = '201902'
group by 
    cast(Grade as varchar(max))
    ,cast(Name as varchar(max))

    union all

select 
    cast(Grade as varchar(max)) as Grade
    ,cast(Name as varchar(max)) as Name
    ,'AVG' as Metric
    ,cast(avg(Amount) as varchar(max)) as '201902'
from [dbo].[example] 
where MonthEnd = '201902'
group by 
    cast(Grade as varchar(max))
    ,cast(Name as varchar(max))


select 
    cast(Grade as varchar(max)) as Grade
    ,cast(Name as varchar(max)) as Name
    ,'SUM' as Metric
    ,cast(sum(Amount) as varchar(max)) as '201903'
into #temp3
from [dbo].[example] 
where MonthEnd = '201903'
group by 
    cast(Grade as varchar(max))
    ,cast(Name as varchar(max))

    union all

select 
    cast(Grade as varchar(max)) as Grade
    ,cast(Name as varchar(max)) as Name
    ,'AVG' as Metric
    ,cast(avg(Amount) as varchar(max)) as '201903'
from [dbo].[example] 
where MonthEnd = '201903'
group by 
    cast(Grade as varchar(max))
    ,cast(Name as varchar(max))

select 
    a.Grade
    ,a.Name
    ,a.Metric
    ,a.[201901]
    ,b.[201902]
    ,c.[201903]
from #temp1 a
left join #temp2 b
on  a.Grade = b.Grade and a.Name = b.Name and a.Metric = b.Metric
left join #temp3 c
on  a.Grade = c.Grade and a.Name = c.Name and a.Metric = c.Metric

Answer 1

输出是一个有 2 列和 2 行的表。 Column1 标头是 Metric，Column2 标头是 201901，然后 row1 column1 表示 Total_Weight，row1 column2 是 sum(weight) 函数生成的值。

你把它弄反了。将每个指标设为单独的列，并为每个月和性别设置单独的行。

（月份、性别、平均年龄、总体重、...）

如果您需要以不同方式显示的数据，请在前端担心，或者在构建结果集后使用 TSQL PIVOT。

Answer 2

我能够使用枢轴方法来生成所需的结果