[nhibernate-issues] [NHJIRA] Commented: (NH-2648) HQL with joins in sub-select creates wrong SQL

[Harald M. M. (J. <nh...@gm...>]

    [ http://216.121.112.228/browse/NH-2648?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=20904#action_20904 ] 

Harald M. Müller commented on NH-2648:
--------------------------------------

I looked a little bit in the code and found the following in HqlSqlWalker.g:

    fromElement! 
    ...:
       | je=joinElement 
          -> //$je

i.e., the return $je of a joinElement is commented, so it returns the null tree. Probably, global joins are handled via some global variable machinery (there is a call to CreateFromJoinElement(...) inside joinElement's production), but this appears not to work for subqueries. Maybe this helps to solve this issue.


> HQL with joins in sub-select creates wrong SQL
> ----------------------------------------------
>
>                 Key: NH-2648
>                 URL: http://216.121.112.228/browse/NH-2648
>             Project:  NHibernate
>          Issue Type: Bug
>          Components: Core
>    Affects Versions: 3.2.0Beta1
>            Reporter: Harald M. Müller
>            Priority: Critical
>         Attachments: HQL_MissingJoinInExists.zip
>
>
> The following query is translated to wrong SQL - the join is missing from the sub-select:
>     SELECT ROOT FROM NHibernate.Test.NHSpecificTest.HQL_MissingJoinInExists.Sheet AS ROOT 
>                             WHERE (EXISTS (FROM NHibernate.Test.NHSpecificTest.HQL_MissingJoinInExists.Shelf AS inv  
>                                            JOIN ROOT.Folder AS ROOT_Folder 
>                                            WHERE (((ROOT_Folder.Shelf) = (inv) AND inv.Id = 1)) )) 
>                                   AND ROOT.Name = 'SomeName'
> (The query was created by a HQL generator of ours - hence the superfluous parentheses). The exceotion is:
> NHibernate.Exceptions.GenericADOException : could not execute query
> [ select sheet0_.Id as Id2_, sheet0_.Name as Name2_, sheet0_.Folder as Folder2_ from Sheet sheet0_ where (exists (select shelf1_.Id from Shelf shelf1_ where folder2_.Shelf=shelf1_.Id and shelf1_.Id=1)) and sheet0_.Name='SomeName' ]
> [SQL: select sheet0_.Id as Id2_, sheet0_.Name as Name2_, sheet0_.Folder as Folder2_ from Sheet sheet0_ where (exists (select shelf1_.Id from Shelf shelf1_ where folder2_.Shelf=shelf1_.Id and shelf1_.Id=1)) and sheet0_.Name='SomeName']
>   ----> System.Data.SqlClient.SqlException : The multi-part identifier "folder2_.Shelf" could not be bound.
> Since NHib 0.99 and in Hibernate, it has been possible to use joins inside subqueries. HQL allows it, and therefore, it should produce correct SQL (both syntactically and semantically). Actually, joins in subqueries are *necessary* if there are OR or NOT operators inside the subquery (some simpler queries can be rewritten with all Joins at top-level).
> I consider this bug critical because there is no workaround for
> * HQL generated for earlier NHib versions
> * manual HQL that needs OR or NOT inside a subquery
> * (I assume) the correct translation of Linq's .Any in the NHib.Linq provider
> I have attached a test case that shows the behavior.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://216.121.112.228/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira