Wrong alias in Where clause if using Fetch and scalar Select #3263
Description
I have two entities (Employee and OptionaInfo) which are linked over HasOne mappings. When running this query:
_session.Query<Employee>()
.Fetch(x => x.OptionalInfo)
.Where(x => x.OptionalInfo != null)
.Select(x => x.OptionalInfo.Age)
.ToList();I get this error:
could not execute query
[
select optionalin1_.Age as col_0_0_
from Employee employee0_
left outer join OptionalInfo optionalin1_ on employee0_.EmployeeId=optionalin1_.EmployeeId
where optionalin2_.EmployeeId is not null
]
PostgresException: 42P01: missing FROM-clause entry for table »optionalin2_«
NHibernate uses alias optionalin2_ but doesn’t define it. If I change optionalin2_ to optionalin1_ manually, the query works.
The error only occurs if the Fetch method is present. Without Fetch everything works as expected.
I tested NHibernate versions 5.4.1, 5.4.0 and 5.3.15. The error appears in 5.4.1 and 5.4.0. Version 5.3.15 works just fine. I'm using PostgreSQL.
Here are my entities and maps:
public class Employee
{
public virtual int EmployeeId { get; set; }
public virtual string Name { get; set; }
public virtual OptionalInfo? OptionalInfo { get; set; }
}
public class OptionalInfo
{
public virtual int EmployeeId { get; set; }
public virtual int Age { get; set; }
public virtual Employee Employee { get; set; }
}
public class EmployeeMap : ClassMap<Employee>
{
public EmployeeMap()
{
Table("Employee");
Id(x => x.EmployeeId).GeneratedBy.Identity();
Map(x => x.Name).Not.Nullable();
HasOne(x => x.OptionalInfo).Cascade.SaveUpdate();
}
}
public class OptionalInfoMap : ClassMap<OptionalInfo>
{
public OptionalInfoMap()
{
Table("OptionalInfo");
Id(x => x.EmployeeId).GeneratedBy.Foreign("Employee");
Map(x => x.Age).Not.Nullable();
HasOne(x => x.Employee).Cascade.None();
}
}