Question

我需要一些关于SQL代码的帮助。我有2个表，第一个是表名

NameID   Name      
1          John          
2          Paul          
3          Jessica          
4          Nancy          
5          Sam          
6          Jane
7          Jimmy

第二个是表Family

 FamilyID   NameID    ChildID
    1          1           2
    2          1           3
    3          2           4
    4          3           5
    5          3           6
    6          5           7

字段＆＃34; NameID＆＃34;和＃34; ChildID＆＃34;在表中，Family连接到字段＆＃34; NameID＆＃34;在表名称中。所以，如果我把它放在一棵树上就会像这样

         John
         /  \
      Paul  Jessica
      /       /  \
   Nancy    Sam  Jane
            /
          Jimmy

我需要的是能够找到＆＃34; All＆＃34;的SQL代码。父母一定记录。例如：

我想知道Jane的所有父母，结果将是：Jessica，约翰
我想知道吉米的所有父母，结果将是：山姆，杰西卡，约翰
我想了解南希的所有家长，结果将是：保罗，约翰

Answer 1

在这里，使用递归CTE如下：

  DECLARE @pName VARCHAR(20)
  SET @pName = 'Jane'

  ;WITH  RecursiveFamilyCTE
          AS (
               SELECT
                ParentName.NAME,
                ParentName.NameID,
                f.ChildID
               FROM
                dbo.Family AS f
                JOIN NAME AS ChildName
                  ON f.ChildID = ChildName.NameID
                JOIN Name AS ParentName
                  ON f.NameID = ParentName.NameID
               WHERE
                 ChildName.NAME = @pName

               UNION ALL

               SELECT 
                ParentName.NAME,
                ParentName.NameID,
                f.ChildID
               FROM
                dbo.Family AS f
                JOIN NAME AS ChildName
                  ON f.ChildID = ChildName.NameID
                JOIN Name AS ParentName
                  ON f.NameID = ParentName.NameID
                JOIN RecursiveFamilyCTE
                  ON f.ChildID = RecursiveFamilyCTE.NameID
             )
    SELECT
      NAME
    FROM
      RecursiveFamilyCTE

Answer 2

递归查询是继续查询的方法。下面是一个灵活的查询，您可以在没有参数的情况下运行。

with familytree as (
  select childid, nameid 
  from family
  where nameid is not null

  union all

  select f.childid, t.nameid  
  from familytree t 
  inner join family f on t.childid = f.nameid
),
treedetails as (
  select
    p.nameid as parentid, p.name as parent, 
    c.nameid as childid, c.name as child
  from familytree a
  left join name p on a.nameid = p.nameid
  left join name c on a.childid = c.nameid
)
-- uncomment the query of your choice
-- select * from treedetails where child = 'Jimmy'
-- select * from treedetails where child = 'Jane' 
-- select * from treedetails where child = 'Nancy'
-- 
-- show me children and grandchildren of Jessica
-- select * from treedetails where parent = 'Jessica'

示例：http://www.sqlfiddle.com/#!3/f7030/4

根据特定记录查找所有父母

2 个答案: