ActiveRecord 映射

Question

早上好，伙计们。

我对 NHibernate 生成的查询有疑问。我的映射如下所示：

public class Matricula
{
       [BelongsTo("IdTurma", NotNull=True)]
       public Turma {get;set;}      
}

public class Turma
{
      [BelongsTo("IdCurso", NotNull=True)]
      public Curso {get;set;}
}

public class Curso
{
       [PrimaryKey("IdCurso", Generator=PrimaryKeyType.Identity)]
       public int IdCurso{get;set;}
}

问题是： Nh 生成查询，其中左侧应位于内部。在 Matricula 和 Turma 之间，他们使内部成为内部，但在 Turma 和 Curso 之间，他们使外部成为左外部。有什么问题吗？怎么了？

我的查询：

SELECT  this_.IdMatricula as IdMatric1_122_14_, 
  this_.IdTurma as IdTurma122_14_, 
  this_.IdUsuario as IdUsuario122_14_, 
  turma3_.IdTurma as IdTurma25_0_, 
  turma3_.idTurmaStatus as idTurmaS2_25_0_,   
  turma3_.IdCurso as IdCurso25_0_,   
  curso4_.IdCurso as IdCurso31_1_, 
  curso4_.idStatus as idStatus31_1_, 
  curso4_.IdTipoCurso as IdTipoC10_31_1_, 
  curso4_.IdOrganization as IdOrgan11_31_1_,   
  statuscurs5_.idStatus as idStatus54_2_, 
  statuscurs5_.strStatus as strStatus54_2_, 
  tipocurso6_.strDescricao as strDescr2_125_3_, 
  padraocomu7_.strNmPadrao as strNmPad2_103_4_, 
  organizati8_.Id_Organization as Id1_87_5_, 
  organizati8_.strTitle as strTitle87_5_,
  cursoprese9_.IdCurso as IdCurso6_6_, 
  turmastatu10_.idTurmaStatus as idTurmaS1_91_7_,   
  usuario1_.IdUsuario as IdUsuario116_10_, 
  organizaca14_.idOrganizacao as idOrgani1_83_11_, 
  cargo15_.idCargo as idCargo7_12_,
  matriculas16_.idMatriculaStatus as idMatric1_15_13_
   FROM tracking.matriculas this_ 
 inner join cursos.turmas turma3_ on this_.IdTurma=turma3_.IdTurma 
 left outer join schemadbo.cursos curso4_ on turma3_.IdCurso=curso4_.IdCurso 
 left outer join schemadbo.status statuscurs5_ on curso4_.idStatus=statuscurs5_.idStatus 
 left outer join schemadbo.tipos tipocurso6_ on curso4_.IdTipoCurso=tipocurso6_.IdTipoCurso 
 left outer join schemadbo.PadraoComunicacao padraocomu7_ on curso4_.IdPadraoComunicacao=padraocomu7_.IdPadrao 
 left outer join schemadbo.lms_cp_organizations organizati8_ on curso4_.IdOrganization=organizati8_.Id_Organization 
 left outer join schemadbo.CursosPresenciais cursoprese9_ on curso4_.IdCurso=cursoprese9_.IdCurso 
 left outer join schemadbo.turmasstatus turmastatu10_ on turma3_.idTurmaStatus=turmastatu10_.idTurmaStatus 
 left outer join schemadbo.turmaspresenciais turmaprese11_ on turma3_.IdTurma=turmaprese11_.idTurma 
 inner join schemadbo.matriculasresumo matricular12_ on this_.IdMatricula=matricular12_.IdMatricula 
 inner join schemadbo.usuarios usuario1_ on this_.IdUsuario=usuario1_.IdUsuario 
 left outer join schemadbo.Organizacoes organizaca14_ on usuario1_.idOrganizacao=organizaca14_.idOrganizacao 
 left outer join schemadbo.cargos cargo15_ on usuario1_.idCargo=cargo15_.idCargo 
 inner join schemadbo.matriculasstatus matriculas16_ on this_.idMatriculaStatus=matriculas16_.idMatriculaStatus 
  WHERE this_.IdTurma = @p0

Answer 1

我们最后遇到了类似的问题。为了提高性能，我们将 FetchEnum.Join 添加到 BelongsTo 属性中，这对我们来说很有效。

[BelongsTo("IdCurso", NotNull = true, Fetch=FetchEnum.Join)]