Question

我遇到导航属性未加载的问题。我对所有其他实体都有相同的设置，但这是使用不是自然FK（数字）且不会级联的属性，它将由触发器处理。

Expression<Func<DivisionBracketGameParticipant, object>>[] includes2 = {
                                                                                       q => q.DivisionWinnerBracketGame,
                                                                                       q => q.DivisionLoserBracketGame
                                                                                   };
            var test = _divisionBracketGameParticipantsRepository.GetMany(includes2,
                                                                      q =>
                                                                      q.DivisionBracketGame.DivisionBracket.Division.
                                                                          EventId == eventId);

数据库架构

DivisionBracketGame

Id
Number

DivisionBracketGameParticipant

Id
DivisionBracketGameId -> Id
DivisionBracketGameWinnerNumber -> Number
DivisionBracketGameLoserNumber -> Number

实体

[Table("DivisionBracketGame", Schema = "GrassrootsHoops")]
    public class DivisionBracketGame : BaseEntity
    {
        public int Id{ get; set; }
        public int Number { get; set; }

        [InverseProperty("DivisionBracketGame")]
        public virtual ICollection<DivisionBracketGameParticipant> DivisionBracketGameParticipants { get; set; }

        [InverseProperty("DivisionWinnerBracketGame")]
        public virtual ICollection<DivisionBracketGameParticipant> DivisionWinnerBracketGameParticipants { get; set; }

        [InverseProperty("DivisionLoserBracketGame")]
        public virtual ICollection<DivisionBracketGameParticipant> DivisionLoserBracketGameParticipants { get; set; }
    }

[Table("DivisionBracketGameParticipant", Schema = "GrassrootsHoops")]
public class DivisionBracketGameParticipant : BaseEntity
    {
        public int Id{ get; set; }
        public virtual int DivisionBracketGameId { get; set; }
        public virtual int? DivisionWinnerBracketGameNumber { get; set; }
        public virtual int? DivisionLoserBracketGameNumber { get; set; }

        [ForeignKey("DivisionBracketGameId")]
        public virtual DivisionBracketGame DivisionBracketGame { get; set; }

        [ForeignKey("DivisionWinnerBracketGameNumber")]
        public virtual DivisionBracketGame DivisionWinnerBracketGame { get; set; }

        [ForeignKey("DivisionLoserBracketGameNumber")]
        public virtual DivisionBracketGame DivisionLoserBracketGame { get; set; }
    }

Answer 1

EF不会与Number建立关系，因为它不是主键。主要密钥属于DivisionBracketGame Id，因此DivisionWinnerBracketGame和DivisionLoserBracketGame都定位Id（不是Number）。

一对多关系要求主表中的列是唯一的 - 在您的情况下，列应为Number。通过使用主表的主键或在该列上使用唯一索引，可以在数据库中实现这一点。 EF不支持唯一索引/候选键，因此在EF中构建一对多关系的唯一方法是通过主表的主键。

FK值用于获取相关值，因此它可能会查找具有错误值的记录，因为它使用了错误的列。

实体框架代码首先不拉动导航属性

1 个答案: