在各自的父记录中选择子记录的总数

Question

我有一个父子关系（层次模型）的帐户图表表。 该表包含两种类型的账户控制账户和交易账户。

交易账户有余额，但没有任何子账户。

控制帐户没有自己的余额，但他们带有子帐户。

---

 
AccountID|  Title  |AccountType|ParentID| Balance 
---------|----------------|-----------|--------|--------- 
1  | Assets   |  c  | null | null 
1-1  | Current Assets |  c  | 1  | null 
1-1-1 | Cash   |  t  | 1-1 | 1000 
1-1-2 | Inventory  |  t  | 1-1 | 2000 
1-2  | Fixed Assets |  c  | 1  | null 
1-2-1 | Furniture  |  t  | 1-2 | 1500 
1-2-2 | Building  |  t  | 1-2 | 3000 

---

我需要一个结果集，如：

---

 
AccountID|  Title  |AccountType|ParentID| Balance 
---------|----------------|-----------|--------|--------- 
1  | Assets   |  c  | null | 7500 --sum of current and fixed Assets 
1-1  | Current Assets |  c  | 1  | 3000 --sum of cash and inventory 
1-1-1 | Cash   |  t  | 1-1 | 1000 
1-1-2 | Inventory  |  t  | 1-1 | 2000 
1-2  | Fixed Assets |  c  | 1  | 4500 --sum of furniture and building 
1-2-1 | Furniture  |  t  | 1-2 | 1500 
1-2-2 | Building  |  t  | 1-2 | 3000 

---

事务表

---

 
ID |AccountID|Amount 
---|---------|------ 
1 | 1-1-1 | 300 
2 | 1-1-1 | 700 
3 | 1-1-2 | 1500 
4 | 1-1-2 | 500 
5 | 1-2-1 | 700 
6 | 1-2-1 | 800 
7 | 1-2-2 | 2000 
8 | 1-2-2 | 1000 

任何选择语句如果可能 或函数或存储过程。

任何帮助将不胜感激

Answer 1

方法1（感谢asantaballa用于转移我的注意力向的CTE）

With TrialBalance(AccountID, ParentID, Balance) 
AS 
(
Select AccountId, ParentID, Balance From Accounts Where AccountType = 't' 
Union All 
Select A.AccountId, A.ParentID, T.Balance From Accounts A 
Inner Join TrialBalance T On A.AccountId = T.ParentID 
) 
Select AccountID, SUM(Balance) From TrialBalance Group By AccountID  

方法2

Create Function AccountBalance(@AccountID Nvarchar(100)) 
Returns Float 
AS 
Begin 
Declare @Balance Float 
Select @Balance = Balance From Accounts Where AccountID = @AccountID 
Select @Balance += Sum(dbo.AccountBalance(AccountID)) From Accounts 
Where ParentID = @AccountID 
Return @Balance 
End 

Select AccountID, dbo.AccountBalance(AccountID) From Accounts 

以上两种方法返回期望的结果。

Answer 2

有这样做的方法很多，但是我有几个更新语句做到了。 请注意，您还没有提供的数据库结构，所以我想你有2个表中，一个与账户和其他与余额的交易账户：

create table #accounts (
AccountId int 
,Title varchar(60) 
,AccountType varchar(10) 
,ParentID int 
,Balance int 
) 
create table #transactional_accounts (
Id int 
,AccountID int 
,Amount int 
) 

insert into #accounts (AccountId, Title, AccountType,ParentID) values 
.............. 
insert into #transactional_accounts values 
........... 

update #accounts 
set Balance= (select SUM(amount) from #transactional_accounts t2 where t1.AccountId= t2.AccountID ) 
from #accounts t1 
where AccountType ='t' 


update #accounts 
set Balance= case when t1.ParentID is not null then (select SUM(t2.Balance) from #accounts t2 where t1.AccountId=t2.ParentID) 
      else (select SUM(t2.Balance) from #accounts t2) 
      end 
from #accounts t1 
where AccountType ='c' 

select * from #accounts