C# 实体框架-使用多列索引作为标识符的种子添加或更新

我试图使用

context.AddOrUpdate

方法为数据库种子，但问题是我需要基于多列索引使插入的数据唯一

[Table("climbing_grades")]
public class ClimbingGrade : EntityBase
{
    /// <summary>
    /// The name of the climbing grade, e.g.: 7a, VII, etc.
    /// </summary>
    [Index("IX_Name_GradeType", 1, IsUnique = true)]
    public string Name { get; set; }

    /// <summary>
    /// Tries to display the average difficulty of the described grade.
    /// Matching the different grades can be difficult because its always
    /// a subjective rating and there exists no norm on converting grades.
    /// </summary>
    public double Difficulty { get; set; }

    /// <summary>
    /// The type of the grade. Will be the respective region rating.
    /// e.g.: UUIA for most oft europe, YSD for USA, etc.
    /// </summary>
    [Index("IX_Name_GradeType", 2, IsUnique = true)]
    public ClimbingGradeType GradeType { get; set; }
}

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插入种子数据时是否可以比较多列索引？

您需要使用匿名类型来指定多列。这也可以在不指定标记的情况下工作

context.ClimbingGrades.AddOrUpdate(grade => new { grade.Name, grade.GradeType },
    new ClimbingGrade
    {
        Name = "5a",
        Difficulty = 4.75,
        GradeType = ClimbingGradeType.FontainebleauBloc
    },
    new ClimbingGrade
    {
        Name = "5a",
        Difficulty = 4.25,
        GradeType = ClimbingGradeType.FontainebleauTraverse
    });

---

你所说的“有可能比较…？”是什么意思？你到底想做什么？是否只保留一些可能重复的值？如果数据库中已经存在数据集，我希望使用多列索引作为引用。e、 g.：

.AddOrUpdate（grade=>grade.Name==existing.Name&&grade.GradeType==existing.GradeType）

context.ClimbingGrades.AddOrUpdate(grade => new { grade.Name, grade.GradeType },
    new ClimbingGrade
    {
        Name = "5a",
        Difficulty = 4.75,
        GradeType = ClimbingGradeType.FontainebleauBloc
    },
    new ClimbingGrade
    {
        Name = "5a",
        Difficulty = 4.25,
        GradeType = ClimbingGradeType.FontainebleauTraverse
    });