DevForce Community Forum : Need help with Join in Lambda expression. http://www.ideablade.com/forum/ This is an XML content feed of; DevForce Community Forum : DevForce 2010 : Need help with Join in Lambda expression. Wed, 29 Jul 2026 12:18:50 -700 Wed, 12 Jan 2011 12:06:25 -700 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 9.69 360 www.ideablade.com/forum/RSS_post_feed.asp?TID=2424 DevForce Community Forum http://www.ideablade.com/forum/forum_images/IdeaBlade_logo_tm.png http://www.ideablade.com/forum/ Need help with Join in Lambda expression. : Hi Bill, try: var records... http://www.ideablade.com/forum/forum_posts.asp?TID=2424&PID=9631#9631 Author: sbelini
Subject: 2424
Posted: 12-Jan-2011 at 12:06pm

Hi Bill,
 
try:
 
var records = from m in Mgr.Members
                      from jH in Mgr.JobHistories
                      where m.SocSecNo == jH.SocSecNo
                      && jH.TSFinish == null
                      select m;
 
or
 
var records = mgr.Members
        .SelectMany(jH => mgr.Jobhistories, (m, jH) => new { m = m, jH = jH })
        .Where((w) => (w.m.SocSecNo == w.jH.SocSecNo && w.jH.TSFinish== null))
        .Select(m => m.m);
 
note that in the latter you will want to have only Distinct results.
 
Silvio.
]]> Wed, 12 Jan 2011 12:06:25 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=2424&PID=9631#9631 Need help with Join in Lambda expression. : var records = Mgr.Members .Where(m... http://www.ideablade.com/forum/forum_posts.asp?TID=2424&PID=9594#9594 Author: BillG
Subject: 2424
Posted: 07-Jan-2011 at 4:53pm

var records = Mgr.Members

.Where(m => m.Status == "A" && m.DuesRate > 0 && m.DuesDeduction == "Y")

.Join(Mgr.JobHistories, m => m.SocSecNo, jh => jh.SocSecNo, (m, jh) => new { members = m })

.Select(m => m)

.ExecuteAsync();

so how can I add the Jobhistory to the where clause. I need to search for jh.TSFinish is null in addition to the above where criteria.
]]> Fri, 07 Jan 2011 16:53:40 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=2424&PID=9594#9594 Need help with Join in Lambda expression. : Hi Bill, What's the result... http://www.ideablade.com/forum/forum_posts.asp?TID=2424&PID=9593#9593 Author: sbelini
Subject: 2424
Posted: 07-Jan-2011 at 1:45pm

Hi Bill,

 
What's the result you are trying to retrieve from the query? (Members?, JobHistories?, JobSites?, a projection with more than one entity type?)
 
Below is a simple example returning Members
 
.var records = Mgr.Members
.Where(m => m.Status == "A" && m.DuesRate > 0 && m.DuesDeduction == "Y")
//.Select(m => m)
 
.Join(Mgr.JobHistories
  , m => m.SocSecNo, jH => SocSecNo
  ,(m, jH) => new {members = m})
.Select(m = m.members)
 
.ExecuteAsync();
 
You mentioned that you need to do a Join Member and JobHistory (the example above describes it) and a Join on JobHistory and JobSite.
Do you want all this joins in one query? Or are they separate queries?
Also, note that for your Join between JobHistory and JobSite,where you have 2 conditions, (EmployerNo and JobSiteNo) using query comprehension syntax might actually be simpler:
 
var query = from jH in mgr.JobHistories
                   from jS in mgr.JobSites
                   where jH.EmployerNo == jS.EmployerNo
                   && jH.JobSiteNo == jS.JobSiteNo
                   select new { JobHistory = jH, JobSite = jS };
 
 
]]> Fri, 07 Jan 2011 13:45:56 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=2424&PID=9593#9593 Need help with Join in Lambda expression. : Here is my linq statement so far. var... http://www.ideablade.com/forum/forum_posts.asp?TID=2424&PID=9584#9584 Author: BillG
Subject: 2424
Posted: 06-Jan-2011 at 10:45pm

Here is my linq statement so far.
 

var records = Mgr.Members

.Where(m => m.Status == "A" && m.DuesRate > 0 && m.DuesDeduction == "Y")

.Select(m => m)

.ExecuteAsync();

 
Now I need to add a .Join() statement. I need to join Member  on SocSecNo to JobHistory on SocSecNo
and (JobHistory to JobSite on both EmployerNo and JobSiteNo)
 
Thanks
Bill
 
]]> Thu, 06 Jan 2011 22:45:10 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=2424&PID=9584#9584