在一个关键列上加入两个linq查询以获得一个结果集

Question

在这里，我想将第一个查询（一列）输出到第二个查询的结果以获得一个结果集。我怎样才能将它们合并（根据需要CONCAT不起作用例如：VAR QUERY2 = query.concat（QUERY1））。

var query = (from PP in _db.paymentPlans 
        join APP in _db.Applications on PP.applicationID equals  APP.ApplicationId 
        join C in _db.Courses on APP.courseID equals C.courseID 
        where PP.active == true && APP.agentID == agentID 
        orderby C.courseID ascending 
        group new {C,PP} by new {C.courseID} into totalRecievable 
         select new PdPpAppCourseModel 
        { 
         courseID = totalRecievable.Key.courseID,        
         totalAmount = totalRecievable.Sum(x => x.PP.totalAmount) 
        }).ToList(); 


      var query1=(from PD in _db.paymentDetails 
        join PP in _db.paymentPlans on PD.paymentPlanID equals PP.paymentPlanID 
        join APP in _db.Applications on PP.applicationID equals APP.ApplicationId 
        join C in _db.Courses on APP.courseID equals C.courseID 
        where PP.active == true && APP.agentID == agentID 
        orderby C.courseID ascending 
        group new { C,PD } by new { C.courseID, C.cricosCode, C.courseName } into paymentsCourseWise 

        select new PdPpAppCourseModel 
        { 
         courseID = paymentsCourseWise.Key.courseID, 
         cricosCode = paymentsCourseWise.Key.cricosCode, 
         courseName = paymentsCourseWise.Key.courseName, 
         paidAmount = paymentsCourseWise.Sum(x => x.PD.paidAmount) 

        }).ToList(); 

Answer 1

您可以加入QUERY1和查询这样

var result = (from q1 in query1 
      join q in query on q1.courseID = q.courseID 
      select new PdPpAppCourseModel 
      { 
       courseID = q1.Key.courseID, 
       cricosCode = q1.Key.cricosCode, 
       courseName = q1.Key.courseName, 
       paidAmount = q1.Sum(x => x.PD.paidAmount), 
       totalAmount = q.totalAmount 

      }).ToList();