title: How to linq join if datatable doesn't have all the rows
body: <p>I'm having an issue where I'm getting nothing back. Here is my code:</p>
  
  <pre><code>var final = (from table1 in dtS.AsEnumerable()
                   join table2 in DataDT.AsEnumerable()
                      on table1.Field&lt;string&gt;(1) equals table2.Field&lt;string&gt;(0)
                   join table3 in DataDT2.AsEnumerable() 
                      on table1.Field&lt;string&gt;(1) equals table3.Field&lt;string&gt;(0)
                   join table4 in DataDT3.AsEnumerable()
                      on table1.Field&lt;string&gt;(1) equals table4.Field&lt;string&gt;(0)
                   select new Model
                   {
                       TestID = table1.Field&lt;int&gt;(0),
                       ID = table1.Field&lt;string&gt;(1),
                       Name = table1.Field&lt;string&gt;(2),
                       Absent = table1.Field&lt;bool&gt;(3),
                       Gender = table1.Field&lt;string&gt;(4),
                       Grade = table1.Field&lt;int&gt;(5),
                       TestDate = table1.Field&lt;string&gt;(7),
                       SessionNumber = table1.Field&lt;int&gt;(8),
                       Room = table1.Field&lt;string&gt;(9),
                       Code = table1.Field&lt;string&gt;(10),
                       Booklet = table1.Field&lt;string&gt;(11),
                       Color = table4.Field&lt;string&gt;(3),
                       Accomm = table3.Field&lt;string&gt;(1),
                       SID = table2.Field&lt;string&gt;(1),
                       LocalName = table2.Field&lt;string&gt;(2)
  
                   }).ToList();
  </code></pre>
  
  <p>If I comment out the last two joins and "Color, Accomm, SID and Local" . I seem to get all of my info.</p>
  
  <p>table1 has 300 rows. This has all the people</p>
  
  <p>table2 has 1000 rows. Has some extra data I need to add</p>
  
  <p>table3 has 10. Has some extra data that I need to add (but doesn't have everyone)</p>
  
  <p>table4 has 17. Has some extra data that I need to add (but doesn't have everyone)</p>
  
  <p>Doesn't seem to "Linq" up (<strong>drums</strong>). Thanks for the help. I know I'm over thinking something..</p>