EF is mapping to the wrong keys on entities

问题

When I run a linq query it's trying to map the SchoolInfo.SchoolInfoId to the SchoolId.SchoolId.

How do I define the correct mapping so it knows to map SchoolInfo.SchoolId to School.SchoolId?

This is Code-First.

SQL Tables

table School
(
    int SchoolId not null PK
)

table SchoolInfo
(
    int SchoolInfoId not null PK
    int SchoolId not null FK
)

Models

class School
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    int schoolId;

    virtual SchoolInfo SchoolInfo;
}

class SchoolInfo
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    int schoolInfoId;

    int schoolId;

    virtual School School
}

modelBuilder.Entity<School>().HasOptional(a => a.SchoolInfo).WithRequired(a => a.School);

回答1:

A more appropriate way to do is something like:

Data Base:

TABLE School (
    INT SchoolId NOT NULL PK
)

TABLE SchoolInfo (
    INT SchoolId NOT NULL PK -- FK
)

School Model:

public class School
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int schoolId { get; set; }

    public virtual SchoolInfo SchoolInfo { get; set; }
}

SchoolInfo Model Option 1:

public class SchoolInfo
{
    [Key, ForeignKey("School")]
    public int schoolId { get; set; }

    public virtual School School { get; set; }
}

SchoolInfo Model Option 2:

public class SchoolInfo
{
    [ForeignKey("School")]
    public int SchoolInfoId { get; set; }

    public virtual School School { get; set; }
}

SchoolInfo Model Option 3:

public class SchoolInfo
{
    [Key]
    public int schoolId { get; set; }

    public virtual School School { get; set; }
}

// Relationship:

modelBuilder.Entity<School>().HasOptional(a => a.SchoolInfo).WithRequired(a => a.School);

An alternative way because of the restrictions you mentioned is something like:

Your actual Data Base:

TABLE School (
    INT SchoolId NOT NULL PK
)

TABLE SchoolInfo (
    INT SchoolInfoId NULL PK
    INT SchoolId NOT NULL FK -- WITH UNIQUE CONSTRAINT TO ENSUERE ONE TO ONE
)

School Model:

public class School
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int schoolId { get; set; }

    public virtual SchoolInfo SchoolInfo { get; set; }
}

SchoolInfo Model Option 1:

public class SchoolInfo
{
    public int schoolInfoId { get; set; }

    [Key]
    public int schoolId { get; set; }

    public virtual School School { get; set; }
}

// Relationship:

modelBuilder.Entity<School>().HasOptional(a => a.SchoolInfo).WithRequired(a => a.School);

SchoolInfo Model Option 2 (I did not test it):

public class SchoolInfo
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int schoolInfoId { get; set; }

    [ForeignKey("School")]
    public int schoolId { get; set; }

    public virtual School School { get; set; }
}

// Relationship:

modelBuilder.Entity<School>().HasOptional(a => a.SchoolInfo).WithRequired(a => a.School);

You can see:

http://www.entityframeworktutorial.net/entity-relationships.aspx http://www.entityframeworktutorial.net/code-first/configure-one-to-one-relationship-in-code-first.aspx

来源：https://stackoverflow.com/questions/37349886/ef-is-mapping-to-the-wrong-keys-on-entities

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