NHibernate - 根据子属性过滤结果

Question

我有这段代码获取所有启用的组及其子组。我遇到的问题是子项也可以被禁用，但我无法让 nhibernate 只获取启用了所有子项的组。我认为这是可能的，但如何实现呢？

public class Group {
    public bool IsDisabled { get; set; }
    public string Description { get; set; }
    public ICollection<ChildType> Children { get; protected set; }
}

public class ChildType {
    public bool IsDisabled { get; set; }
    public string Description { get; set; }
}

public IList<Group> Search(string searchString) {
    IQueryOver<Group> query = Session.QueryOver<Group>()
        .WhereRestrictionOn(x => x.Description).IsInsensitiveLike(searchString, MatchMode.Start)
        .Where(x => !x.IsDisabled)
        .OrderBy(x => x.Description).Asc
        .Fetch(group => group.Children).Eager;

    return query
        .Cacheable()
        .List();
}

编辑：子项和组之间存在 N:M 关系。

以下是我使用的解决方案：

public class Group {
    public long Id { get; set; }
    public bool IsDisabled { get; set; }
    public string Description { get; set; }
    public ICollection<ChildType> Children { get; protected set; }
}

public class ChildType {
    public long Id { get; set; }
    public bool IsDisabled { get; set; }
    public string Description { get; set; }
    public ICollection<Group> Groups { get; protected set; }
}

public IList<Group> Search(string searchString) {
    ChildType child = null;
    Group group = null;
    Group joinedGroup = null;

    var notDisabled = Session.QueryOver.Of<ExaminationType>()
        .Where(x => x.IsDisabled)
        .JoinAlias(x => x.Groups, () => joinedGroup )
            .Where(x => joinedGroup == group)
        .Select(x => x.Id);

    IQueryOver<Group> query = Session.QueryOver<Group>()
        .WhereRestrictionOn(x => x.Description).IsInsensitiveLike(searchString, MatchMode.Start)
        .JoinAlias(x => x.ExaminationTypes, () => child)
        .WithSubquery.WhereNotExists(notDisabled)
        .OrderBy(x => x.Description).Asc;

    return query
        .Cacheable()
        .List();
}

Answer 1

您需要使用子查询才能实现您想要的。为了做到这一点，您需要添加对 ChildType 实体的 Group 引用。

Group group = null;
var childCrit = QueryOver.Of<ChildType>()
        .Where(c => c.Group == group).And(c => c.IsDisabled)
        .Select(c => c.Id);
var query = Session.QueryOver(() => group)
        .WhereRestrictionOn(x => x.Description).IsInsensitiveLike(searchString, MatchMode.Start)
        .Where(x => !x.IsDisabled)
        .WithSubquery.WhereNotExists(childCrit)
        .OrderBy(x => x.Description).Asc
        .Fetch(group => group.Children).Eager;

这将获得所有没有残疾并且没有残疾儿童的组。

Answer 2

public IList<Group> Search(string searchString) {

    Children children = null;

    IQueryOver<Group> query = Session.QueryOver<Group>()
        .WhereRestrictionOn(x => x.Description).IsInsensitiveLike(searchString, MatchMode.Start)
        .Where(x => !x.IsDisabled)
        .JoinAlias(x => x.Children, () => children)
            .Where(x => !x.IsDisabled)
        .OrderBy(x => x.Description).Asc;

    return query
        .Cacheable()
        .List();
}

那应该做你想做的事。

加入别名也会为您获取它。

http://www.philliphaydon.com/2011/04/ nhibernate-querying-relationships-are-deep/