Question

我有一个混乱的数据集，我需要为特定的父帐户获取所有子帐户。

表格如下

代码（PK），名称，ParentCode

没有外键

如果帐户没有父级，我可以看到，ParentCode是一个空字符串，或者它设置为与代码相同。

我一直在尝试关注http://msdn.microsoft.com/en-us/library/ms186243(v=sql.105).aspx，但它似乎正在返回所有数据，而且我无法弄清楚如何只为一个帐户获取孩子。

WITH DirectReports (ParentCus, Code, Name, Level)
AS
(
    SELECT ParentCode, Code, Name, 0 AS Level
    FROM Customers
      WHERE Code = ParentCode OR Code = ''
    UNION ALL

    SELECT c.ParentCode, c.Code, c.Name, level + 1
    FROM Customers AS C
    INNER JOIN DirectReports AS d
        ON c.ParentCode = d.Code
        where c.Code != d.Code
)
SELECT ParentCus, Code, Name, Level
FROM DirectReports

修改的为了清楚起见，我需要能够通过我的函数代码并返回所有（递归）帐户子帐户。

最终代码 我不得不对答案稍作修改，但这是最终的工作代码

declare @t table(code varchar(10), name varchar(10), parentcode varchar(10))
insert @t values(1, 'navn1', '1')
insert @t values(2, 'navn2', '')
insert @t values(3, 'navn3', 1)
insert @t values(4, 'navn4', 3)
insert @t values(5, 'navn5',4)
insert @t values(6, 'navn6', 2)
insert @t values(7, 'navn7', 3)

declare @code varchar(10) -- or however code/parentcode is declared
set @code = '1'           -- the parentcode you are trying to isolate

;WITH DirectReports (ParentCus, Code, Name, Level)
AS
(
    SELECT ParentCode, Code, Name, 0 AS Level
    FROM @t Customers
    -- this picks the chosen code
      WHERE Code = @code and (Code = ParentCode OR PARENTCode = '')
    UNION ALL
    SELECT c.ParentCode, c.Code, c.Name, level + 1
    FROM
        (select * from @t where  code !=  parentcode) --had to do this to account for an infinate loop
        as C
    INNER JOIN DirectReports AS d
        ON c.ParentCode = d.Code

)
SELECT ParentCus, Code, Name, Level
FROM DirectReports
-- level > 0: to ensure child accounts only
where level > 0

Answer 1

;With CTE as 
(
select ParentCode, Code, Name,row_number() over (order by (select 0)) as rn from Customers
)

,DirectReports as (ParentCus, Code, Name, Level)
AS
(
    SELECT rn,ParentCode, Code, Name, 0 AS Level
    FROM CTE WHERE rn=1 and (Code = ParentCode OR Code = '')
    UNION ALL

    SELECT c.ParentCode, c.Code, c.Name, level + 1
    FROM CTE AS C
    INNER JOIN DirectReports AS d
        ON c.ParentCode = d.Code and c.rn=d.rn+1
        where c.Code != d.Code
)
SELECT ParentCus, Code, Name, Level
FROM DirectReports

Answer 2

您需要指定所需的代码。此示例使用@t替换表Customers

declare @t table(code varchar(10), name varchar(10), parentcode varchar(10))
insert @t values(1, 'navn1', '')
insert @t values(2, 'navn2', '')
insert @t values(3, 'navn3', 1)

declare @code varchar(10) -- or however code/parentcode is declared
set @code = '1'           -- the parentcode you are trying to isolate

;WITH DirectReports (ParentCus, Code, Name, Level)
AS
(
    SELECT ParentCode, Code, Name, 0 AS Level
    FROM @t Customers
    -- this picks the chosen code
      WHERE Code = @code and (Code = ParentCode OR PARENTCode = '')
    UNION ALL
    SELECT c.ParentCode, c.Code, c.Name, level + 1
    FROM @t C
    INNER JOIN DirectReports AS d
        ON c.ParentCode = d.Code
    -- added to prevent infinite loop, 
    -- I should point out that when this happens, you have bad data in your base
    WHERE c.ParentCode <> c.Code
)
SELECT ParentCus, Code, Name, Level
FROM DirectReports
-- level > 0: to ensure child accounts only
-- level < 100:to prevent infinite loops caused by circular references
where level > 0 and level < 100

递归SQL查询

2 个答案: