Question

我有这些课程：

public class Document
{
    public Document()
    {
        Descriptions = new List<Descriptions>();
    }

    public virtual int Id { get; set; }
    public virtual IList<DocumentDescription> Descriptions { get; set; }
}

public class DocumentDescription
{
    public virtual int DocumentId { get; set; }
    public virtual int LanguageId { get; set; }
}

和映射：

public DocumentMap()
{
    Id(x => x.Id);

    HasMany(x => x.Descriptions).KeyColumn("DocumentId");
}

public DocumentDescriptionMap()
{
    CompositeId()
        .KeyProperty(x => x.DocumentId)
        .KeyProperty(x => x.LanguageId);
}

我的查询是：

var query = Session.QueryOver<Document>().Where(x => x.Id.IsIn(documentIds)).List();

我需要对解决方案进行查询，以便用少量语言限制DocumentDescriptions，我将获得运行时间。我不想获得一个文档的所有DocumentDescriptions（只有少数）。是否可以为子集合设置过滤器/限制？

Answer 1

所以，我找到了如何在我的查询中添加额外的join子句：

DocumentDescription dd = null;
ICriterion criterion = Restrictions.On<DocumentDescription>(x => x.LanguageId).IsIn(languageIds.ToArray());

var query = Session.QueryOver<Document>().Where(x => x.Id.IsIn(documentIds));
query.Left.JoinQueryOver(x => x.Descriptions, () => dd, criterion);

SQL：

SELECT * FROM tDocument
LEFT OUTER JOIN tDocumentDescription ON tDocumentDescription.DocumentId = tDocument.Id AND tDocumentDescription.LanguageId IN (@languageIds)
WHERE tDocument.Id IN (@documentIds)

nhibernate儿童收藏限制

1 个答案: