title: Can't Display null with second column in datagridview, from 2 tables
body: <pre><code>#i have two tables buyers table and sales table#
  </code></pre>
  
  <p>buyers table </p>
  
  <hr>
  
  <p>|buyer | balance|      </p>
  
  <p>sales table<br>
   |buyer | sales|buydate|              </p>
  
  <p>I have tried the following select query</p>
  
  <pre><code>Dim connection As OleDbConnection  
  Dim adapter As OleDbDataAdapter  
  Dim ds As New DataSet  
  Dim SQLStr As String  
  Dim cmd As OleDbCommand  
  connection = New  
  OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data 
  Source=consignacion.mdb;")    
  SQLStr = "SELECT b.buyer as [Buyer],b.balance as 
  [Balance],SUM(s.total) as [Sales],  
  b.balance+SUM(s.total) as [Total] From buyerdb b  
  INNER Join salesdb s on b.buyer=s.buyer  
  WHERE s.total Is Not NULL And  
  s.buydate =@buydate And  
  s.total&lt;&gt;@sales AND  
  b.balance&gt; @balance  
  GROUP By b.buyer,b.balance"  
  SQLStr = "SELECT b.buyer as [Buyer],b.balance as 
  [Balance],SUM(s.total) as [Sales],  
  b.balance+SUM(s.total) as [Total] From buyerdb b  
  INNER Join salesdb s on b.buyer=s.buyer  
  WHERE s.total Is Not NULL And  
  s.buydate =@buydate And s.total&lt;&gt;@sales AND b.balance&gt; @balance  
  GROUP By b.buyer,b.balance"  
  cmd = New OleDbCommand(SQLStr, connection)  
  cmd.Parameters.AddWithValue("@buydate", Form1.Lbldate2.Text)  
  cmd.Parameters.AddWithValue("@balance", 0)  
  cmd.Parameters.AddWithValue("@sales", "")
  </code></pre>
  
  <blockquote>
  <pre><code>   I expect the output to be  
  
    buyer   balance  sales   total
    CESS    350 984 1334
    DARWIN  0 345 345
    GLEN    1000 4334 5334
    GLENDA  0 170 170
    JOSE    1000 2240 3240
    LITO    0 120 120
    LOUIE   0 280 280
    TANIS   0 2250 2250
    YOLLY   1500 832 2332
    michael 1500 [null/norecor] 1500
    Dudice   700 [null/norecord] 700
  
  
      but the output is     
  </code></pre>
    
    <p>buyer   balance  sales   total     </p>
  </blockquote>
  
  <pre><code>    CESS      350      84      334    
  &gt;    DARWIN 0   345 345    
  &gt;    GLEN   1000    4334    5334    
  &gt;    GLENDA 0   170 170    
  &gt;    JOSE   1000    2240    3240    
  &gt;    LITO   0   120 120    
  &gt;    LOUIE  0   280 280    
  &gt;    TANIS  0   2250    2250    
  &gt;    YOLLY  1500    832 2332    
  </code></pre>
  
  <blockquote>
    <p><strong>it is not displaying buyers with balance but no recorded sales on the given buydate</strong></p>
  </blockquote>
  
  <p>i have tried everything i know. i even search google and youtube and seems can't get the right output on my data grid view.</p>