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POInner Join on three tables using Linq
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  1. POInner Join on three tables using Linq
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    copied!<p>How to do inner join on three tables, when one of the tables is using group by. I am able to write this query but it returns error on run time. So how should I modify my query.</p> <pre><code>var pastDate = DateTime.Now.Date.AddDays(-1); var query = from l in db.picturelikes where l.iddatetime &gt; pastDate group l by l.idpictures into pgroup let count = pgroup.Count() orderby count descending join p in db.picturedetails on pgroup.FirstOrDefault().idpictures equals p.idpictures join u in db.users on pgroup.FirstOrDefault().iduser equals u.iduser select new SortedDto { IdPictures = pgroup.FirstOrDefault().idpictures, IdUser = pgroup.FirstOrDefault().iduser, totalrating = pgroup.Average(l =&gt; (float?)l.likenumber) ?? 0, // pl.Where(a =&gt; a.likenumber!= null).Average(c =&gt; c.likenumber) sex =u.sex, username =u.username, dob = u.dob }; return query; </code></pre> <p>This is the exception i get with my present code, </p> <blockquote> <p>InnerException: { Message: "An error has occurred.", ExceptionMessage: "Unknown column 'Project2.idpictures' in 'where clause'", ExceptionType: "MySql.Data.MySqlClient.MySqlException", StackTrace: " at MySql.Data.MySqlClient.MySqlStream.ReadPacket() at MySql.Data.MySqlClient.NativeDriver.GetResult(Int32&amp; affectedRow, Int64&amp; insertedId) at MySql.Data.MySqlClient.Driver.GetResult(Int32 statementId, Int32&amp; affectedRows, Int64&amp; insertedId) at MySql.Data.MySqlClient.Driver.NextResult(Int32 statementId, Boolean force) at MySql.Data.MySqlClient.MySqlDataReader.NextResult() at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader(CommandBehavior behavior) at MySql.Data.Entity.EFMySqlCommand.ExecuteDbDatoiaReader(CommandBehavior behavior) at System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior) at System.Data.EntityClient.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)" }</p> </blockquote> <p>Is my query legit? Is it the way to do three inner joins when using groupby.</p>
 

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