Question

是否可以从源对象映射到源对象不同的目标对象？配置表通过 Code 属性具有与查找表相关的对象（一种松散耦合场景）由于遗留原因，源对象中不能存在 ServiceLookup 和 ClassificationLookup。

这些是表格。

CREATE TABLE Config ( Id                       INT IDENTITY (1, 1) NOT NULL
,                     Code                     NVARCHAR (50) NOT NULL
,                     ServiceLookupCode        NVARCHAR (50) NOT NULL
,                     ClassificationLookupCode NVARCHAR (50) NOT NULL
,                     SomeConfigValue          NVARCHAR (50) NOT NULL
,                     CONSTRAINT PK_Table1 PRIMARY KEY CLUSTERED (Id ASC)
,                     CONSTRAINT UQ_Table1_Code UNIQUE NONCLUSTERED (Code ASC) );

CREATE TABLE ServiceLookup ( Id   int IDENTITY(1,1) NOT NULL
,                            Code nvarchar(50) NOT NULL
,                            Name nvarchar(255) NOT NULL
,                            CONSTRAINT PK_ServiceLookup PRIMARY KEY CLUSTERED (Id ASC)
,                            CONSTRAINT UQ_ServiceLookup_Code UNIQUE NONCLUSTERED (Code ASC) );

CREATE TABLE ClassificationLookup ( Id   int IDENTITY(1,1) NOT NULL
,                                   Code nvarchar(50) NOT NULL
,                                   Name nvarchar(255) NOT NULL
,                                   CONSTRAINT PK_ClassificationLookup PRIMARY KEY CLUSTERED (Id ASC)
,                                   CONSTRAINT UQ_ClassificationLookup_Code UNIQUE NONCLUSTERED (Code ASC) );

返回数据的SQL示例

SELECT c.Id, c.Code, c.SomeConfigValue
,      sl.Name AS ServiceName
,      cl.Name AS ClassificationName
FROM       Config               c 
INNER JOIN ServiceLookup        sl ON c.ServiceLookupCode = sl.Code
INNER JOIN ClassificationLookup cl ON c.ClassificationLookupCode = cl.Code

实体 ServiceLookup 和 ClassificationLookup 表无法在 Config 表中定义（遗留原因）

public class Config
{
    public int Id { get; set; }
    public string Code { get; set; }
    public string ServiceLookupCode { get; set; }
    public string ClassificationLookupCode { get; set; }
    public string SomeConfigValue { get; set; }

    //public ServiceLookup ServiceLookup { get; set; } <-- This is not allowed due to loose coupling design (legacy reasons)
    //public ClassificationLookup ServiceLookup { get; set; } <-- This is not allowed due to loose coupling design (legacy reasons)
}

public class ServiceLookup
{
    public int Id { get; set; }
    public string Code { get; set; }
    public string Name { get; set; }
}

public class ClassificationLookup
{
    public int Id { get; set; }
    public string Code { get; set; }
    public string Name { get; set; }
}

DTO

public class ConfigDto 
{
    public int Id { get; set; }
    public string Code { get; set; }
    public string ServiceLookupCode { get; set; }
    public string ClassificationLookupCode { get; set; }
    public string SomeConfigValue { get; set; }

    public LookupModel ServiceLookup { get; set; }
    public LookupModel ClassificationLookup { get; set; }
            
    public class LookupModel
    {
        public int Id { get; set; }
        public string Code { get; set; }
        public string Name { get; set; }
    }
}

Linq 代码

var result = await (from c in Db.Config
    join sl in Db.ServiceLookup on c.ServiceLookupCode equals dl.Code
    join cl in Db.ClassificationLookup on c.ClassificationLookupCode equals cl.Code
    select new ConfigDto
    {
        Id = c.Id,
        Code = c.Code,
        SomeConfigValue = c.SomeConfigValue,
        ServiceLookupCode = c.ServiceLookupCode,
        ClassificationLookupCode = c.ClassificationLookupCode,
        ServiceLookup = new ConfigDto.LookupModel
        {
            Id = sl.Id,
            CodePath = sl.Code,
            Name = sl.Name
        },
        ClassificationLookup = new ConfigDto.LookupModel
        {
            Id = cl.Id,
            Code = cl.Code,
            Name = cl.Name
        }
    }
)

源属性不存在的自定义映射

0 个答案: