Question

一个具有挑战性的问题，我有如下表格

EmployeeID BossID

pic http://img16.imageshack.us/img16/7659/20130430113245.jpg

创建查询的任何想法，以便当某个员工进入时，它会查询他下面的所有员工以及谁是他的老板

Answer 1

尝试此查询

你必须像Sohail所提到的那样使用CTE。

WITH DirectReports (bossId, EmpID, Level)
AS
(
-- Anchor member definition
    SELECT bossId, empId,
        0 AS Level
    FROM tbl
    WHERE empId = 2
    UNION ALL
-- Recursive member definition
    SELECT e.bossId, e.empId,
        Level + 1 AS Level
    FROM tbl e
    INNER JOIN DirectReports AS d
        ON e.bossId = d.empId
)
-- Statement that executes the CTE
SELECT *
FROM DirectReports;

的 SQL FIDDLE

| BOSSID | EMPID | LEVEL | -------------------------- | 1 | 2 | 0 | | 2 | 4 | 1 | | 4 | 5 | 2 | | 4 | 6 | 2 |

Answer 2

您应该使用CTE（公用表表达式）创建查询。如需帮助，请阅读Recursive Queries

以下是您可以根据需要修改的类似示例，但这会有所帮助。

这是一个表结构。

CREATE TABLE [dbo]。[分类]（ [Id] [bigint] IDENTITY（1,1）NOT NULL， [CategoryName] varchar NULL， [ParentId] [bigint] NULL）

这是分层查询。我刚刚为它创建了一个视图，因为我需要在我的场景中更多地过滤它。

    CREATE VIEW [dbo].[CategoriesWithNameHierarchy] AS WITH Categories_Tree AS
        (SELECT c.id AS 'Id' ,
            0 AS 'Level',
            c.CategoryName AS 'CategoryName',
            cast(c.CategoryName AS varchar(30)) AS 'CNameHierarchy'
           FROM Categories c
   WHERE ParentId IS NULL
   UNION ALL SELECT ChildCategories.Id AS 'Id',
                    (1 + ct.[Level]) AS 'Level',
                    ChildCategories.CategoryName AS 'CategoryName',
                    cast(ct.CNameHierarchy + '>' + ChildCategories.CategoryName AS varchar(30)) AS 'CNameHierarchy'
   FROM Categories ChildCategories,
                   Categories_Tree ct
   WHERE ChildCategories.ParentId = ct.Id)
SELECT *
FROM Categories_Tree

希望这会有所帮助。

SQL QUERY选择特定boss下的员工

2 个答案:

的 SQL FIDDLE