SQL Server case when 日期字符串转换 多表查询 嵌套子查询

select distinct stu.*,

dbo.GetClassNameByStudentCode(stu.Code) as ClassName,dbo.GetCourseNameByStudentCode(stu.Code)  CourseName,dbo.GetLinkmanByStudentId(stu.Id)  Linkman,dbo.GetContactByStudentId(stu.Id)  Contact,
case when svr.Linkman is not NULL then svr.Linkman else dbo.GetLinkmanByStudentId(stu.Id) end  VisitLinkman,when svr.Contact then svr.Contact else dbo.GetContactByStudentId(stu.Id)  VisitContact,1)">when u1.Sname NULL and u1.Sname<>'' then u1.Sname else u1.Username  VisitFollowUserName,1)">CONVERT(CHAR(10),svr.FollowTime,23)  VisitLastFollowTime,
scl.Name as SchoolAreaName,
svr.ContentMemo as VisitContentMemo,
dict1.Name as StudentStatusName

from FM_Student stu 

left join FM_StudentClass sc on stu.Code=sc.Code
join FM_Class cls on cls.ClassCodesc.ClassCode 
join FM_Course cou on cou.Idcls.CourseId 
join FM_CourseSubject cs on cs.Idcou.CourseSubjectId
join FM_StudentContact cc on cc.StudentIdstu.Id
join FM_SchoolArea scl on scl.Idstu.SchoolAreaId

join FM_StudentVisitRecord svr on svr.Id
(top 1 svr1.Id  FM_Student stu1
join FM_StudentVisitRecord svr1 
on stu1.Code=svr1.Code and stu1.Id=stu.Id order by svr1.Id desc)

join Sys_User u1 on u1.Idsvr.FollowUserID
join Sys_Dict dict1 on dict1.Type='{1}' and dict1.Codestu.StudentStatus

where stu.DelFlg<>{0}

 

*,scl.Name  SchoolAreaName,dbo.GetClassNameByStudentCode(stu.Code)  VisitContentMemo,dict1.Name  StudentStatusName,((select sum(pf.PayAmount) 
 FM_PayFlow pf
join FM_Student stu1 on pf.CustomerCode=stu1.Code and stu1.Code=stu.Code) -

((psf.PayAmount) 
 FM_PayStepFlow psf 
join FM_PayFlow pf1 on psf.PayFlowIdpf1.Id
on pf1.CustomerCode=stu.Code))  as ArrearageAmount --欠费金额

0} and (sc.Status{2}or sc.Status is NULL 
        and    
        ((pf.PayAmount) 
         FM_PayFlow pf
        >

        ((psf.PayAmount) 
         FM_PayStepFlow psf 
        pf1.Id
        =stu.Code)