NHibernate Filters on Left Outer Joins

I am running into an issue with an NHibernate filter. It works great until I do a left outer join to the object.

For example, Deal references PurchaseItem, but PurchaseI开发者_开发问答tem has a CompanyId filter applied.

If I want to query deal with a left join to PurchaseItem, the CompanyId filter is applied in the WHERE clause, causing nothing to return.

Is there a way to apply the filter at the join instead of at the where clause?

Fixed this by using this filter condition: "CompanyId is NULL or CompanyId = :companyId"

This is ok because CompanyId is not-null in SQLServer so we should only get NULL if we are doing an outer join.

I'm looking for this exact problem with nullable optional fields

Note your OR will avoid using indexes so it may be slower.

UPDATE: I think I found the fix:

                // register filters
                var filterDef = new FilterDefinition(
                    "f_CurrentTenant",
                    "TenantId = :f_tenantId",
                    new Dictionary<string, IType> { { "f_tenantId", NHibernateUtil.Guid } },
                    **false**);
                config.AddFilterDefinition(filterDef);

When you create the filter, you can set the last parameter called "useManyToOne" = false. This will tell NH to not use the filter on the joins.

So far it seems it has worked :D