SQL按数据分组条件筛选

我有一个表数据如下：

Customer    Level   Dept
AAA 1   Parent
AAA 2   Corporate
AAA 3   SmallBusiness
BBB 1   Parent
BBB 2   StateLevel
BBB 3   Education
BBB 4   RegionLevel
CCC 1   Parent
CCC 2   Sales
CCC 3   Healthcare
CCC 4   Online
CCC 5   Web

条件： 如果级别=2且部门=公司

用户部门是公司的

如果级别为3且（部门=教育或部门=体育），则为其他

用户部门是教育部门

如果级别为2且部门=销售和级别为3且部门=医疗保健，则为else

使用部门是医疗保健部门

期望输出

Customer Department
AAA  Corporate
BBB  Education
CCC  Healthcare

---

实际上，您在这里根本并没有分组，而是根据现有列的条件创建一个新列。您要使用

CASE

语句：

SELECT CASE WHEN Level = 2 AND Dept = 'Corporate' THEN 'Corporate' 
            WHEN Level = 3 AND (Dept = 'Education' OR Dept = 'Sport') THEN 'Education'
            WHEN (Level = 2 AND Dept = 'Sales') OR (Level = 3 AND Dept = 'HealthCare') THEN 'HealthCare'
            ELSE NULL END AS [Department]
FROM [YourTableName]
WHERE (Level = 2 AND Dept = 'Corporate')
OR    (Level = 3 AND (Dept = 'Education' OR Dept = 'Sport'))
OR    (Level = 2 AND Dept = 'Sales') 
OR (Level = 3 AND Dept = 'HealthCare') 

相应地调整你的逻辑-你的问题的格式很难知道括号应该放在哪里-它们很重要

---

编辑：根据@scsimon的建议，添加了一个

WHERE

子句。

您实际上根本没有在此处分组-您正在根据现有列的条件创建一个新列。您要使用

CASE

语句：

SELECT CASE WHEN Level = 2 AND Dept = 'Corporate' THEN 'Corporate' 
            WHEN Level = 3 AND (Dept = 'Education' OR Dept = 'Sport') THEN 'Education'
            WHEN (Level = 2 AND Dept = 'Sales') OR (Level = 3 AND Dept = 'HealthCare') THEN 'HealthCare'
            ELSE NULL END AS [Department]
FROM [YourTableName]
WHERE (Level = 2 AND Dept = 'Corporate')
OR    (Level = 3 AND (Dept = 'Education' OR Dept = 'Sport'))
OR    (Level = 2 AND Dept = 'Sales') 
OR (Level = 3 AND Dept = 'HealthCare') 

相应地调整你的逻辑-你的问题的格式很难知道括号应该放在哪里-它们很重要

---

编辑：根据@scsimon的建议添加了一个

WHERE

子句。

简单的案例陈述应该可以做到这一点。。。我把最后一个逻辑子句改为OR，因为行不能是2级和3级

select distinct
customer,
case 
   when Level=2 and Dept='Corporate' then 'Corporate'
   when Level=3 and (Dept='Education' or Dept='Sport') then 'Education'
   when (Level = 2 and Dept='Sales') or (Level=3 and Dept='Healthcare') then 'Healthcare'
end as 'Department'
from
   SomeTable
where
   Level in (2,3)

---

简单的案例陈述就可以了。。。我把最后一个逻辑子句改为OR，因为行不能是2级和3级

select distinct
customer,
case 
   when Level=2 and Dept='Corporate' then 'Corporate'
   when Level=3 and (Dept='Education' or Dept='Sport') then 'Education'
   when (Level = 2 and Dept='Sales') or (Level=3 and Dept='Healthcare') then 'Healthcare'
end as 'Department'
from
   SomeTable
where
   Level in (2,3)

---

在这些条件上构建一些东西：

Case
when (level = 2 AND Dept = 'Corporate') Then Corporate
when (level = 3 AND Dept in ('Education','Sport)) Then Education
when (level = 2 AND Dept = 'Sales') Then Healthcare
when (level = 3 AND Dept = 'Healthcare') Then Healthcare
Else Null
End as col

---

在这些条件上构建一些东西：

Case
when (level = 2 AND Dept = 'Corporate') Then Corporate
when (level = 3 AND Dept in ('Education','Sport)) Then Education
when (level = 2 AND Dept = 'Sales') Then Healthcare
when (level = 3 AND Dept = 'Healthcare') Then Healthcare
Else Null
End as col

---

你可以在需要的时候用一个箱子

   select customer, 
        case when dept = 'Corporate' and level = 2 then 'Corporate'
             when ( dept =  'Education' or dept ='Sport' and level = 2 then 'Education'
             when  (level = 2 and dept ='Sales') and ( level=3 and dept = 'HealthCare' ) then 'HealthCare'
             else 'Unknow' end my_dept
  from table 

---

你可以在需要的时候用一个箱子

   select customer, 
        case when dept = 'Corporate' and level = 2 then 'Corporate'
             when ( dept =  'Education' or dept ='Sport' and level = 2 then 'Education'
             when  (level = 2 and dept ='Sales') and ( level=3 and dept = 'HealthCare' ) then 'HealthCare'
             else 'Unknow' end my_dept
  from table 

---

根据你的逻辑，它是这样的：

SELECT Customer,
    CASE WHEN Level=2 AND Dept='Corporate' THEN 'Corporate'
         WHEN Level=3 AND (Dept='Education' OR Dept='Sort') THEN 'Education'
         WHEN Level=2 AND (Dept='Sales' AND Level=3) AND Dept='HealthCare'
         END AS [Department] FROM [YourTable]

---

根据你的逻辑，它是这样的：

SELECT Customer,
    CASE WHEN Level=2 AND Dept='Corporate' THEN 'Corporate'
         WHEN Level=3 AND (Dept='Education' OR Dept='Sort') THEN 'Education'
         WHEN Level=2 AND (Dept='Sales' AND Level=3) AND Dept='HealthCare'
         END AS [Department] FROM [YourTable]

---

另一个选择是通过枢轴

示例

Declare @YourTable Table ([Customer] varchar(50),[Level] int,[Dept] varchar(50))
Insert Into @YourTable Values 
 ('AAA',1,'Parent')
,('AAA',2,'Corporate')
,('AAA',3,'SmallBusiness')
,('BBB',1,'Parent')
,('BBB',2,'StateLevel')
,('BBB',3,'Education')
,('BBB',4,'RegionLevel')
,('CCC',1,'Parent')
,('CCC',2,'Sales')
,('CCC',3,'Healthcare')
,('CCC',4,'Online')
,('CCC',5,'Web')

Select Customer
      ,Dept     = concat(
                         case when [2] in ('Corporate') then 'Corporate' end
                        ,case when [3] in ('Education','Sport') then 'Education' end
                        ,case when [2] in ('Sales') and [3]='Healthcare' then 'Healthcare' end
                        )
 From (
        Select *
         From  @YourTable
         Pivot (max([Dept]) For [Level] in ([2],[3]) ) p
      ) A

返回

Customer    Dept
AAA         Corporate
BBB         Education
CCC         Healthcare

---

另一个选择是通过枢轴

示例

Declare @YourTable Table ([Customer] varchar(50),[Level] int,[Dept] varchar(50))
Insert Into @YourTable Values 
 ('AAA',1,'Parent')
,('AAA',2,'Corporate')
,('AAA',3,'SmallBusiness')
,('BBB',1,'Parent')
,('BBB',2,'StateLevel')
,('BBB',3,'Education')
,('BBB',4,'RegionLevel')
,('CCC',1,'Parent')
,('CCC',2,'Sales')
,('CCC',3,'Healthcare')
,('CCC',4,'Online')
,('CCC',5,'Web')

Select Customer
      ,Dept     = concat(
                         case when [2] in ('Corporate') then 'Corporate' end
                        ,case when [3] in ('Education','Sport') then 'Education' end
                        ,case when [2] in ('Sales') and [3]='Healthcare' then 'Healthcare' end
                        )
 From (
        Select *
         From  @YourTable
         Pivot (max([Dept]) For [Level] in ([2],[3]) ) p
      ) A

返回

Customer    Dept
AAA         Corporate
BBB         Education
CCC         Healthcare

---

---

你的问题到底是什么？您是否尝试自己编写查询？查看

SQl案例

语句提示提示您的问题到底是什么？您是否尝试自己编写查询？查看

SQl Case

语句提示

否则将隐含null

（您不必将其放入，默认情况下它将在那里）。只是FYSA——虽然我确实喜欢看它的可读性。

否则就意味着null（你不必把它放进去，它默认会在那里）。只是FYSA——虽然我确实喜欢看它的可读性。谢谢@scsimon，但我在OP中没有看到任何筛选请求。
WHERE
子句包含什么？好吧，您的查询将返回类似AAA 1 Parent的内容，而它不在预期结果中。检查我的answer@scsimon你说得对——他没有说，但很明显这正是他需要的。我更新了答案。谢谢你的帮助。我想在这里设置条件，当（Level=2和Dept='Sales'）和（Level=3和Dept='HealthCare'）然后是“HealthCare”谢谢@scsimon，但我在OP中没有看到任何筛选请求。
WHERE
子句包含什么，您的查询将返回类似AAA 1 Parent的内容，但它不在预期结果中。检查我的answer@scsimon你说得对——他没有说，但很明显这正是他需要的。我更新了答案。谢谢你的帮助。我想在这里设置条件，当（Level=2和Dept='Sales'）和（Level=3和Dept='HealthCare'）时，那么“HealthCare”我可能是错的，但我认为你需要更新你的
WHERE
子句。你的将在那里为“SmallBusiness”记录重新注册AAA 3空+1，尽管如此。我想在这里设置条件，当（级别=2和Dept='Sales'）和（级别=3和Dept='Healthcare'）然后是“Healthcare”时，如何做到这一点？它不能@SrinivasaRao，如何满足该标准？行是1-5级而不是3-2级。我可能错了，但我认为您需要更新
WHERE
子句。你的将在那里为“SmallBusiness”记录重新注册AAA 3空+1，尽管如此。我想在这里设置条件，当（级别=2和Dept='Sales'）和（级别=3和Dept='Healthcare'）然后是“Healthcare”时，如何做到这一点？它不能@SrinivasaRao，如何满足该标准？一排是1-5级，不是3-2级。简直太棒了。第三个条件对我来说很难实现，这不是其他人所说的简单案例陈述。@SrinivasaRao谢谢。这适用于样本数据，但我有点担心未预期的组合。。。但我认为你得到的是非常棒的。第三个条件对我来说很难实现，这不是其他人所说的简单案例陈述。@SrinivasaRao谢谢。这适用于样本数据，但我有点担心未预期的组合。。。但我想你明白了