以类似树格式的父子格式编写查询

Question

我正在处理一个 MVC C# 项目，我的 SQL 查询有些复杂。我有三张桌子

1. 客户
2. 等级
3. 关卡详情

两个表都有关系

级别映射到级别详细信息，级别详细信息映射到客户和级别

我想以树格式显示该数据，例如：

父级：客户名称 CustomerId 客户类型

     Test          T1          TestCustomer

Child Levelid Leveldesc 城邦

      L1       L1desc     C1    S1

      L2       L2desc     C2    S2

逻辑是，当我单击父项时，它会显示子级别。

我试过这个查询

select LD.Level_Rid, LD.Customer_Rid, LD.Level_Detail_Rid, L.Level_Id, L.Level_Description, L.Country, L.State, L.City, L.Area, CU.Customer_Name, CU.Customer_Type
FROM [dbo].[Level] L
INNER JOIN [dbo].[Level_Detail] LD ON R.Level_Rid = RD.Level_Rid 
INNER JOIN [dbo].[Customer] CU ON LD.Customer_Rid = CU.Customer_Rid

是否可以SQL查询？

Answer 1

我用 cte 写了这个查询：

WITH cte_cu as 
 ( select Customer_Rid from  [dbo].[Customer] as cU )
--select * from  cte_cu where CustomerRid = CustomerRid
select Customer_Rid, 1 orderKeeper,Customer_Name as CustomerName ,[State] as [State],City,Customer_id from  [dbo].[Customer]  where Customer_Rid = Customer_Rid
union
select Customer_Rid,2,'LevelId' as Customer_Name ,'LevelDescription' ,'','' from  [dbo].[Customer]
union
select Customer_Rid,3,Level_Id as Customer_Name ,Level_Description,'','' 
FROM [dbo].[Level_Detail] LD 
inner join dbo.[Level] as L on LD.Level_Rid = L.Level_Rid 
where LD.Customer_Rid = Customer_Rid

结果：

我在 git 中心上传了创建 Table 和插入模拟数据：

https://github.com/mghanatabady/SQL-Samples/blob/master/Write%20Query%20in%20Parent%20Child%20like%20tree%20format.SQL