mysql - 根据状态汇总货币列？

我有一个交叉表查询，可以根据某个记录状态（活动、结束等）对所有记录进行很好的求和

Select
  c.ReferralName,
  Sum((d.CaseStatusName) = 'Active') As Active,
  Sum((d.CaseStatusName) = 'Completed') As Completed,
  Sum((d.CaseStatusName) = 'Submitted') As Submitted,
  Count(b.CaseID) As Total,
  Sum(b.LeadCost) As Cost
From
  tblcontacts a Inner Join
  tblcases b On a.ContactID = b.ContactID Inner Join
  tblreferral c On c.RefferalID = a.ContactReferrelSource Inner Join
  tblcasestatus d On d.CaseStatusID = b.CaseStatusName
Group By
  c.ReferralName With Rollup

这很好，但我现在还想运行一个查询，用b.LeadCost的和替换d.casestusname的和，但是找不到实现它的方法！
我想我需要的是，如果d.CaseStatusName='Active'，则b.LeadCost的总和，等等
非常感谢您的帮助。

最佳答案

Select
  c.ReferralName,
  Sum(CASE WHEN (d.CaseStatusName) = 'Active'    THEN b.LeadCost ELSE 0 END) As Active,
  Sum(CASE WHEN (d.CaseStatusName) = 'Completed' THEN b.LeadCost ELSE 0 END) As Completed,
  Sum(CASE WHEN (d.CaseStatusName) = 'Submitted' THEN b.LeadCost ELSE 0 END) As Submitted,
  Count(b.CaseID) As Total,
  Sum(b.LeadCost) As Cost
From
  tblcontacts a Inner Join
  tblcases b On a.ContactID = b.ContactID Inner Join
  tblreferral c On c.RefferalID = a.ContactReferrelSource Inner Join
  tblcasestatus d On d.CaseStatusID = b.CaseStatusName
Group By
  c.ReferralName With Rollup