NHibernate QueryOver有多个连接别名,只有第一个生成连接

Question

我试图使用JoinAlias加入多个实体,并且无法弄清楚如何让多个实体加入.以下代码导致SQL错误:

[TestMethod]
public void TestAliases()
{
    App_Start.NHibernateProfilerBootstrapper.PreStart();

    var type = new ShirtStyleType {Id = 1};
    var style = new ShirtStyle {Id = 1, ShirtStyleType = type};
    var shirt = new Shirt {Id = 1};
    var shirtStyle = new ShirtShirtStyle {Shirt = shirt, ShirtStyle = style};
    shirt.ShirtStyles = new[] {shirtStyle};

    using (Session.BeginTransaction())
        Session.Save(shirt);

    Session.Clear();

    using (Session.BeginTransaction())
    {
        Shirt shirtAlias = null;
        ShirtShirtStyle shirtStylesAlias = null;
        ShirtStyle shirtStyleAlias = null;
        ShirtStyleType shirtStyleTypeAlias = null;

        var query = Session.QueryOver<Shirt>(() => shirtAlias)
            .JoinAlias(() => shirtAlias.ShirtStyles, () => shirtStylesAlias)
            .JoinAlias(() => shirtStylesAlias.ShirtStyle, () => shirtStyleAlias)
            .JoinAlias(() => shirtStyleAlias.ShirtStyleType, () => shirtStyleTypeAlias)
            .Where(() => shirtStyleTypeAlias.Id == 1)
            .List();
    }
}

错误:

ERROR: 
SQLite error
no such column: shirtstyle3_.Id

导致错误的SQL:

SELECT this_.Id                as Id0_1_,
       shirtstyle1_.Shirt      as Shirt1_0_,
       shirtstyle1_.ShirtStyle as ShirtStyle1_0_
FROM   "Shirt" this_
       inner join "ShirtShirtStyle" shirtstyle1_
         on this_.Id = shirtstyle1_.Shirt_id
WHERE  shirtstyle3_.Id = 1 /* @p0 */

很明显看到错误发生的原因 - 查询缺少连接,特别是除了'ShirtShirtStyle'之外的每个连接.根据我对JoinAlias的理解,我提供的代码应该加入必要的表,但它不是,我不明白为什么.在这种情况下,还有什么我需要让JoinAlias工作吗？

我为此测试创建的实体和映射如下,以防它们如何映射.

实体:

public class Shirt
{
    public virtual int Id { get; set; }
    public virtual IList<ShirtShirtStyle> ShirtStyles { get; set; } 
}

public class ShirtShirtStyle
{
    public virtual Shirt Shirt { get; set; }
    public virtual ShirtStyle ShirtStyle { get; set; }

    protected bool Equals(ShirtShirtStyle other)
    {
        return Equals(Shirt, other.Shirt) && Equals(ShirtStyle, other.ShirtStyle);
    }

    public override bool Equals(object obj)
    {
        if (ReferenceEquals(null, obj)) return false;
        if (ReferenceEquals(this, obj)) return true;
        if (obj.GetType() != this.GetType()) return false;
        return Equals((ShirtShirtStyle) obj);
    }

    public override int GetHashCode()
    {
        unchecked
        {
            return ((Shirt != null ? Shirt.GetHashCode() : 0)*397) ^ (ShirtStyle != null ? ShirtStyle.GetHashCode() : 0);
        }
    }
    }

    public class ShirtStyle
    {
        public virtual int Id { get; set; }
        public virtual ShirtStyleType ShirtStyleType { get; set; }
    }

    public class ShirtStyleType
    {
        public virtual int Id { get; set; }
    }

地图:

public class ShirtMap : ClassMap<Shirt>
{
    public ShirtMap()
    {
        Id(x => x.Id).GeneratedBy.Assigned();
        HasMany(x => x.ShirtStyles);
    }
}

public sealed class ShirtShirtStyleMap : ClassMap<ShirtShirtStyle>
{
    public ShirtShirtStyleMap()
    {
        CompositeId()
            .KeyReference(x => x.Shirt)
            .KeyReference(x => x.ShirtStyle);
    }
}

public sealed class ShirtStyleMap : ClassMap<ShirtStyle>
{
    public ShirtStyleMap()
    {
        Id(x => x.Id).GeneratedBy.Assigned();
        References(x => x.ShirtStyleType);
    }
}

public sealed class ShirtStyleTypeMap : ClassMap<ShirtStyleType>
{
    public ShirtStyleTypeMap()
    {
        Id(x => x.Id).GeneratedBy.Assigned();
    }
}

Answer 1

嗯，这个查询似乎按预期运行 - 问题似乎出在 Fluent NHibernate 上。即使引用是通过 .KeyReference 在复合实体上指定的，您也需要根据/sf/answers/769684051/在映射中显式地重新指定它们。不确定这是否是错误或预期行为。