使用Fluent nHibernate将集合映射到子选择

Question

我有一个看起来像这样的课程：

public class Competitor
{
    public virtual int CompetitorId { get; set; }
    public virtual string FirstName { get; set; }
    public virtual string LastName { get; set; }

    public virtual IEnumerable<string> SportsCompeted { get; set; }
}

SportsCompeted是一个SportID（字符串）列表，如下所示：

SELECT DISTINCT SportID FROM results WHERE competitorId = xxx

我该如何映射这样的东西呢？ 看看HasMany我可以指定一个Where子句，但我不认为这就是我在寻找的情况吗？

我正在使用Fluent Mappings，为简洁起见省略。

Answer 1

您应该可以使用.Element()进行此操作。类似的东西：

HasMany(x => x.SportsCompeted)
    .KeyColumn("CompetitorId")
    .Element("SportID") // You can define element type as second parameter
    .Table("results");

更多信息：
Mapping collection of strings with NHibernate
Fluent NHIbernate automapping of List<string>?

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修改

假设您拥有Result和Sport个实体：

public class Sport
{
    public virtual int SportId { get; set; }
    // Other properties
}

public class Result : Entity
{
    public virtual ResultId { get; set; }
    public virtual Competitor Competitor { get; set; }
    public virtual Sport Sport { get; set; }
    // Other properties
}

public class Competitor
{
    public virtual int CompetitorId { get; set; }
    public virtual IList<Result> Results { get; set; }
    // Other properties
}

您的HasMany现在看起来像这样：

// For this, you would need to have Result and Sport classes mapped
// This property isn't necessary for your Sports Competed query
HasMany(x => x.Results)
    .KeyColumn("CompetitorId")
    .Table("results");

然后你可以使用ie。 Linq得到你想要的结果：

var sports = session.Query<Result>()
    .Where(x => x.Competitor.CompetitorId = competitorId)
    .Select(x => x.Sport) // Or .Select(x => x.Sport.SportId)
    .Distinct();

Answer 2

我最终做的是在SQL中创建一个基本上做的视图：

SELECT DISTINCT SportID, CompetitorID FROM results

然后，在我的映射中：

HasMany(x => x.CompetitorDisciplines)
    .Not.LazyLoad()
    .Inverse()
    .AsBag()
    .KeyColumn("competitorId")
    .Element("DisciplineCode")
    .Table("vCompetitorDisciplines");

这似乎产生了预期的结果 慢，但这只是一次（或每天一次）操作......