Question

我的模型中有一个名为StatusChange的额外字段，这是使用sproc填充来从表中获取所有字段以及额外字段StatusChange

SELECT New.*, [dbo].[ftn_GetStatusChange](Old.MemberStatusId, New.MemberStatusId) AS StatusChange
FROM Member New
LEFT OUTER JOIN Member Old ON New.MemberNo = Old.MemberNo AND Old.ImportHistoryID = @ImportIdToCompare
WHERE New.ImportHistoryID = @NewestImportId

这是函数

CREATE FUNCTION [dbo].[ftn_GetStatusChange]
(
    @OldStatus char,
    @NewStatus char
)
RETURNS int
AS
BEGIN
    IF (@OldStatus IS NULL)
    BEGIN
        RETURN 1
    END

    IF (@OldStatus = 'R') 
        BEGIN
            IF @NewStatus = 'C' RETURN 5
            IF @NewStatus = 'S' RETURN 4
        END

    IF (@OldStatus = 'C')
        BEGIN
            IF @NewStatus = 'R' RETURN 3
            IF @NewStatus = 'S' RETURN 4
        END

    IF (@OldStatus = 'S')
        BEGIN
            IF @NewStatus = 'C' RETURN 5
            IF @NewStatus = 'R' RETURN 3
        END

    RETURN 0
END

这是数字映射到

的枚举

public enum StatusChange
    {
        NoChange = 0,
        New = 1,
        Current = 2,
        Resigned = 3,
        Suspended = 4,
        Reinstated = 5,
    }

数据库表没有字段StatusChange，因为不需要它，所以我尝试将属性Computed添加到C＃中的属性

这是C＃代码

[DatabaseGenerated(DatabaseGeneratedOption.Computed)]
public StatusChange StatusChange { get; set; }

但是当我在DbContext上调用SaveChanges（）时，我收到错误

Invalid column name 'StatusChange'.

无论如何，我只能将这个属性用于SELECT并在INSERT上忽略它吗？

Answer 1

这是未经过测试并且不是100％您想要的，因为很难直观地显示您的数据而不实际拥有它......但也许这会有所帮助..

请用一点盐来很难看到你的数据和要求; - ）

public class Member
{
    [Key][AutoIncromentCode]
    public int Id {get; set;} 
    public string MemberNo {get; set;}
    public string FirstName { get; set;}
    public int MemberStatusId { get; set;}

    public int ImportHistortId { get; set;}

    [NotMapped]
    public MemberStatus
    {
        return (Status)MemberStatusId
    }
}

public enum Status
{
    NoChange = 0,
    New = 1,
    Current = 2,
    Resigned = 3,
    Suspended = 4,
    Reinstated = 5,
}

public class MemberStatusDto
{
    public Member NewMember {get; set;}
    public Member OldMember {get; set;}
}

public void GetSomeStuff(int importHistortId )
{
    List<MemberStatusDto> result  = ( from N_Memeber in Content.Member
                                      join O_Member in Content.Member on 
                                      new { N_Memeber.MemberNo, O_Member.ImportHistortId } equals new {MemberNo = O_Member.MemberNo, ImportHistortId = importHistortId }
                                      into T_Members
                                      from A_Members in T_Members.DefaultIfEmpty()
                                      where N_Memeber.ImportHistoryID = importHistortId
                                     select new MemberStatusDto()
                                     {
                                        NewMember = A_Members.N_Memeber,
                                        OldMember = A_Members.O_Member
                                     }).Tolist();               

    foreach(var item in result)
    {
        var NewState = item.NewMember.MemberStatus;
        var oldState = (item.OldMember == null) ? "nothing" : item.OldMember.MemberStatus

    }
}

实体框架：仅在“插入”上忽略字段

1 个答案: