如何使用 LINQ 从父子关系 Table 获取数据？

Question

我有类似项目 ==> 版本 ==> 冲刺的模式 01 Project01 Null 02 Version01 01 03 Sprint01 02 04 sprint02 02 05 Version02 01 06 Sprint03 05 07 Sprint04 05 08 Project02 Null 等等....

我想检索所有 SprintsId，所以我只是将 Id（这是 sprint/Version/Project 的主键）传递给服务，根据 Id，如果它是 ProjectId（这里是 01）我想检索所有版本（这里是 02,05），然后找到 SprintsId（03,04,06,07），如果它是 VersionsId（这里是 05）我想要所有 SprintsId（06,07）

Answer 1

我找到了使用 SQL Strored Procedure.using 存储过程的解决方案，它不那么复杂

CREATE PROCEDURE [dbo].[USP_Project]
( 
@ID INT
)
AS 
BEGIN
    DECLARE @PROJECT_LEVEL INT =0

    -- IF PROJECT LEVEL IS PROJECT

    SELECT @PROJECT_LEVEL=COUNT(ID) FROM PROJECTS WHERE ID=@ID AND PARENTID IS NULL 
    IF(@PROJECT_LEVEL=1)
    BEGIN  
            SELECT  PROJ.id AS PROJECT_ID,PROJ.Title  ,VER.ID AS VERSION_ID,VER.Title as [Version], SPRI.ID AS SPRINT_ID,SPRI.Title as [Sprint]
            FROM PROJECTS AS PROJ ,PROJECTS AS VER,PROJECTS AS SPRI
            WHERE  PROJ.ID=@ID AND VER.PARENTID=@ID AND SPRI.PARENTID=VER.ID
     END 

     -- IF PROJECT LEVEL IS VERSION
    SELECT   @PROJECT_LEVEL= COUNT(VER.ID)
    FROM        PROJECTS AS PROJ ,PROJECTS AS VER 
    WHERE       VER.PARENTID=PROJ.ID AND PROJ.PARENTID IS NULL AND VER.ID=@ID

    IF(@PROJECT_LEVEL>0)
    BEGIN 
            SELECT PROJ.id AS PROJECT_ID,PROJ.Title  ,VER.ID AS VERSION_ID,VER.Title as [Version], SPR.ID AS SPRINT_ID,SPR.Title as [Sprint]
            FROM PROJECTS AS PROJ  ,PROJECTS AS VER ,PROJECTS AS SPR
            WHERE  VER.ID=@ID AND SPR.PARENTID=@ID AND VER.PARENTID=PROJ.ID
    END 

     -- IF PROJECT LEVEL IS SPRINT

    SELECT @PROJECT_LEVEL=  COUNT(SPR.ID)
    FROM        PROJECTS AS PROJ ,PROJECTS AS VER ,PROJECTS AS SPR
    WHERE     SPR.PARENTID=VER.ID AND VER.PARENTID=PROJ.ID AND PROJ.PARENTID IS NULL AND SPR.ID=@ID 

    IF(@PROJECT_LEVEL>0)
    BEGIN  
            SELECT  PROJ.id AS PROJECT_ID,PROJ.Title  ,VER.ID AS VERSION_ID,VER.Title  as [Version] , SPR.ID AS SPRINT_ID,SPR.Title as [Sprint]
                    FROM PROJECTS AS PROJ ,PROJECTS AS VER ,PROJECTS AS SPR 
                    WHERE  SPR.ID=@ID AND SPR.PARENTID=VER.ID AND VER.PARENTID=PROJ.ID
    END
END

如何使用 LINQ 从父子关系 Table 获取数据？

How to get Data from parent child relationship Table using LINQ?

linq

sql-server

asp.net-mvc-4

entity-framework-6