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POWhat would be a reasonably fast way to code this sql query in c#?
 

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  1. POWhat would be a reasonably fast way to code this sql query in c#?
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    <p>I have this SQL query:</p> <pre><code>select sum(h.nbHeures) from Heures h join HeuresProjets hp on h.HpGuid=hp.HPId join ActivityCodes ac on h.Code=ac.ActivityId join MainDoeuvre mdo on ac.ActivityId=mdo.CodeGuid where hp.ExtraGuid = '61E931C8-3268-4C9C-9FF5-ED0213D348D0' and mdo.NoType = 1 </code></pre> <p>It runs in less than a second, which is good. My project uses LINQ to entities to get data. This (very similar to the sql) query is terribly slow, taking more than a minute.</p> <pre><code> var result = (from hp in this.HeuresProjets join h in ctx.Heures on hp.HPId equals h.HpGuid join ac in ctx.ActivityCodes on h.Code equals ac.ActivityId join mdo in ctx.MainDoeuvre on ac.ActivityId equals mdo.CodeGuid where hp.ExtraGuid == this.EntityGuid &amp;&amp; mdo.NoType == (int)spType select h.NbHeures).Sum(); total = result; </code></pre> <p>I tried using nested loops instead. It's faster but still slow (~15 seconds).</p> <pre><code>foreach (HeuresProjets item in this.HeuresProjets) { foreach (Heures h in ctx.Heures.Where(x =&gt; x.HpGuid == item.HPId)) { if (h.ActivityCodes != null &amp;&amp; h.ActivityCodes.MainDoeuvre.FirstOrDefault() != null &amp;&amp; h.ActivityCodes.MainDoeuvre.First().NoType == (int)type) { total += h.NbHeures; } } } </code></pre> <p>Am I doing something obviously wrong? If there's no way to optimize this I'll just call a stored procedure but I would really like the keep the logic in the code.</p> <p><strong>EDIT</strong></p> <p>I modified my query according to IronMan84's advice.</p> <pre><code>decimal total = 0; var result = (from hp in ctx.HeuresProjets join h in ctx.Heures on hp.HPId equals h.HpGuid join ac in ctx.ActivityCodes on h.Code equals ac.ActivityId join mdo in ctx.MainDoeuvre on ac.ActivityId equals mdo.CodeGuid where hp.ExtraGuid == this.EntityGuid &amp;&amp; mdo.NoType == (int)spType select h); if(result.Any()) total = result.Sum(x=&gt;x.NbHeures); </code></pre> <p>This almost works. It runs fast and gives back a decimal but:<br> 1. It's not the right value<br> 2. The result is clearly cached because it returns the exact same value with different parameters. </p>
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    1. US0xFF
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      1. POWhat would be a reasonably fast way to code this sql query in c#?
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    1. COHave you looked at SQL Profiler to see what SQL the LINQ query is executing under the hood?
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    2. CO@Pete SQL Profiler isn't installed, 'Ill yake a look at it when it finished downloading
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    3. COYou can read the post http://stackoverflow.com/questions/696431/linq-query-with-nullable-sum-problem for your nullable sum problem.
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      1. USFabrice Mainguené
 

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