如何在不使用pivot的情况下将sql中的列转换为行

Question

我被分配从两个表中获取所需格式的数据。

桌员：

StaffID | Staff Name
--------+-----------
 1      | John 
 2      | Jack

和TableLead

LeadID | LeadValue | LeadStaus | StaffID
-------+-----------+-----------+--------
  1    | 5000      | New       | 1
  2    | 8000      | Qualified | 1
  3    | 3000      | New       | 2

您会注意到StaffID 是一个引用TableStaff 的外键。

我必须用以下格式表示数据

StaffID | StaffName | NewLeadCount | QualifiedLeadCount 
--------+-----------+--------------+-------------------
1       | John      |  1           |   1
2       | Jack      |  1           |   0

到目前为止我尝试过的是：

SELECT 
    COUNT([LeadID ]) AS LdCount, 'New' AS StageName  
FROM 
    [dbo].[TableLead] 
WHERE
    [LeadStaus] = 'New' 
UNION 
SELECT 
    COUNT([LeadID ]) AS LdCount, 'Qualified' AS StageName 
FROM 
    [dbo].[TableLead] 
WHERE
    [LeadStaus] = 'Qualified ' 

任何 NULL 点都应替换为 0。谁能告诉我解决问题的正确方向？

Answer 1

我会推荐条件聚合：

select s.staffid, s.staffname, 
    sum(case when l.leadstatus = 'New'       then 1 else 0 end) as newLeadCount,
    sum(case when l.leadstatus = 'Qualified' then 1 else 0 end) as qualifiedLeadCount
from TableStaff s
inner join TableLead l on l.staffid = s.staffid
group by s.staffid, s.staffname