<div>
I think the problem may be that you've put the SUM...-SUM... expression in your &quot;where&quot; clause rather than the &quot;select&quot; part.<br />
<br />

</div>


I think the problem may be that you've put the SUM...-SUM... expression in your "where" clause rather than the "select" part.



<div>
Agreed, I don't know how to complete the code.
</div>


Agreed, I don't know how to complete the code.

<div>
I think it may be as simple as this?<br />
<br />

<pre><code id="code-20-34999084-1">int ret = (from DataRow dr in dt.AsEnumerable() 
	where dr.Field&lt;string&gt;(&quot;Product&quot;) == &quot;BEER&quot; 
	select (SUM(dr.Field&lt;int&gt;(&quot;QtySold&quot;)) - SUM(dr.Field&lt;int&gt;(&quot;QtyBuy&quot;)));</code></pre>
</div>


I think it may be as simple as this?



int ret = (from DataRow dr in dt.AsEnumerable() 
	where dr.Field<string>("Product") == "BEER" 
	select (SUM(dr.Field<int>("QtySold")) - SUM(dr.Field<int>("QtyBuy")));

<div>
The missing code: &quot;Group t By ...&quot;<br />
<br />
Thank You...
</div>


The missing code: "Group t By ..."

Thank You...

<div>
Not a problem, glad I was able to help. &nbsp;;=)
</div>


Not a problem, glad I was able to help.  ;=)

<div>
<div class="content wysiwyg-content">
I have a DataTable with 4 columns (ID, Product, QtySold, QtyBuy). <br />
I would like to return Sum(QtySold) - Sum(QtyBuy). So far not working... <br />
<br />
int ret = (from DataRow dr in dt.AsEnumerable() <br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;where dr.Field&lt;string&gt;(&quot;Product&quot;<wbr />) == &quot;BEER&quot; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&amp;&amp; SUM(dr.Field&lt;int&gt;(&quot;QtySold<wbr />&quot;)) - SUM(dr.Field&lt;int&gt;(&quot;QtyBuy&quot;<wbr />))<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;select ...;<br />
&nbsp; &nbsp; &nbsp; &nbsp; <br />
&nbsp; &nbsp; &nbsp; &nbsp; Label8.Text = &quot;ret= &quot;+ ret.ToString();
</div>
</div>


I have a DataTable with 4 columns (ID, Product, QtySold, QtyBuy). 
I would like to return Sum(QtySold) - Sum(QtyBuy). So far not working... 

int ret = (from DataRow dr in dt.AsEnumerable() 
                       where dr.Field<string>("Product") == "BEER"                      
                       && SUM(dr.Field<int>("QtySold")) - SUM(dr.Field<int>("QtyBuy"))
                       select ...;
        
        Label8.Text = "ret= "+ ret.ToString();

DataSet Sum And Subtract 2 Columns?

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