Gunnar,
Thanks for your help so far. I originally had a UDF, so I've
converted back to the UDF. I've got an extension method for
ResultObject called GetSearchRank, which takes the same parameters as
the UDF in addition the "this" parameter and returns -1 (temporarily
for testing). I've created a dialect that is a subclass of
MsSql2008Dialect, an HQL generator that is a subclass of
BaseHqlGeneratorForMethod, and an HQL generators registry that is a
subclass of another HQL generators registry common to all of our
projects (all it does it add the "trim" function for strings.)
When I try to run the code, the generator registry is getting built,
and execution goes to the BuildHql gets called (I've not yet
implemented it) when I do Session.Query<ResultObject>().OrderBy(ro =>
ro.GetSearchRank("foo", "bar")), but when I do
Session.Query<ResultObject>().Select(ro => ro.GetSearchRank("foo",
"bar")), I just get a queryable full of -1.
How can I get NHibernate to translate the method call to SQL instead
of executing it on the .NET side?
Thanks!
Don
On Aug 30, 7:54 pm, Gunnar Liljas <[email protected]> wrote:
> Since you're inlining this in a SELECT, you should not use your SP. Either
> use FREETEXTTABLE directly or create a UDF.
>
> The steps are:
>
> 1. Customize the SQL dialect and configure NHibernate to use it
> 2. Register the functions in the Linq provider
> 3. Something like what you described.
>
> /G
>
> 2011/8/30 mysterd429 <[email protected]>
>
>
>
>
>
>
>
> > Hi, Gunnar,
>
> > Okay, that will work, I think. I would use my existing stored
> > procedure rather than FREETEXTTABLE. Would these be the steps:
>
> > 1. Customize the LINQ provider using something like
> > RegisterFunction("GetRank", /* SQLFunctionTemplate or
> > StandardSQLFunction, not sure, that calls DO_SEARCH using T-SQL */).
> > 2. Do something like this:
>
> > String field1, field2, field3;
> > // assign field1, field2, field3
> > IQueryable<SearchResult> queryable =
> > Session.Query<ResultObject>().Select(ro => new SearchResult
> > { ResultObject = ro, Rank = GetRank(ro, field1, field2,
> > field3) }).Where(ro => GetRank(ro, field1, field, field3) ?? 0 > 0);
> > if(myUtilityInstance != null) queryable =
> > myUtilityInstance.Paginate(queryable);
> > results = queryable.ToList();
>
> > Does that seem about right? Thanks so much for your help!
>
> > Regards,
>
> > Don
>
> > On Aug 30, 3:40 pm, Gunnar Liljas <[email protected]> wrote:
> > > Hi,
>
> > > While there may be ways to get the result set of a stored procedure into
> > an
> > > NhQueryable, it doesn't make much sense, since any extra Linq predicates
> > you
> > > apply will then by run on the full result set (when paging etc.), and if
> > you
> > > do that, you might just as well apply it after the query, with in memory
> > > operations.
>
> > > I still think that a custom SQL function is feasible. You will have to
> > > reshape it into a scalar value...
>
> > > SELECT ...., (SELECT [RANK] FROM FREETEXTTABLE(tableref,columnref,value)
> > > WHERE [KEY]=tableref.Id) as [RANK] FROM ...
>
> > > Maybe not easy, but doable.
>
> > > /G
>
> > > 2011/8/30 mysterd429 <[email protected]>
>
> > > > Thanks for the reply, Gunnar. Unfortunately, I don't see how I can
> > > > use these links. I'm trying to use FREETEXTTABLE, which provides a
> > > > result set with the search results, not FREETEXT, which is scalar. I
> > > > need to know not only that a row matches, but what its relative rank
> > > > is in the result set. From the MSDN documentation, FREETEXTTABLE
> > > > "[r]eturns a table of zero, one, or more rows for those columns
> > > > containing character-based data types for values that match....
> > > > FREETEXTTABLE can only be referenced in the FROM clause of a SELECT
> > > > statement like a regular table name." The stored procedure I have
> > > > essentially wraps FREETEXTTABLE.
>
> > > > Is there any way to get the result set of a stored procedure into an
> > > > NhQueryable?
>
> > > > Thanks!
>
> > > > On Aug 30, 11:55 am, Gunnar Liljas <[email protected]> wrote:
>
> >http://www.primordialcode.com/blog/post/nhibernate-customize-linq-pro...
>
> > > > > and
>
> >http://darioquintana.com.ar/blogging/2009/03/13/registering-freetext-...
>
> > > > > 2011/8/30 mysterd429 <[email protected]>
>
> > > > > > Hi all,
>
> > > > > > I've got an existing database that uses FREETEXTTABLE in a stored
> > > > > > procedure. I've been using the NHibernate LINQ provider (since
> > we're
> > > > > > switching from LINQ to SQL to NHibernate), and I'd like to know if
> > > > > > there's a way to use FREETEXTTABLE using the LINQ provider. The
> > > > > > stored procedure takes a few parameters and selects the desired
> > result
> > > > > > set (KEY and RANK columns). I have a class for these search result
> > > > > > rows.
>
> > > > > > Currently, I can use the stored procedure using a named SQL query
> > and
> > > > > > get back attached entities:
>
> > > > > > IQuery query = Session.GetNamedQuery("DoSearch");
> > > > > > query.SetParameter("searchTerm", searchTerm);
> > > > > > IList<SearchResult> results = query.List<SearchResult>();
> > > > > > // results[0].ResultObject is the first underlying object.
>
> > > > > > We have a few utility methods that use LINQ for some processing
> > > > > > (sorting, pagination, etc) that I'd like to reuse with this stored
> > > > > > procedure.
>
> > > > > > Ideally, I'd like to do something like:
>
> > > > > > var doSearch =
> > Session.GetQueryableObjectFromNamedQuery("DoSearch");
> > > > > > doSearch.SetParameter("serachTerm", searchTerm);
> > > > > > IQueryable<SearchResult> resultsQueryable = doSearch.AsQueryable();
> > > > > > IList<SearchResult> results =
> > > > > > myUtilityInstance.SortAndPaginate(resultsQueryable);
>
> > > > > > Any ideas? Thanks!
>
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