title: Linq left join with multiple columns and default values
body: <p>I am fairly new to linq and I need to join two tables with the following requirements:</p>
  
  <p>Should left join t1 and t2.</p>
  
  <p>If t2 is empty then the query should not fail - should use default values.</p>
  
  <p>My query:</p>
  
  <pre><code>var final = from t1 in saDist.AsEnumerable()
              from t2 in sapGrouped.AsEnumerable()
              where
                  t1.Supplier.Id == t2.Supplier.Id &amp;&amp; t1.VatRate == t2.VatRate
              select
                  new
                  {
                      t1.Supplier,
                      Amount = t1.Amount - t2.Amount,
                      Advance = t1.Advance - t2.Advance,
                      Balance = t1.Balance - t2.Balance,
                      t1.VatRate
                  };
  </code></pre>
  
  <p>Can someone correct this?</p>