sql-server - 查找所有具有hierarchyid子节点的节点

Question

鉴于此表：

CREATE TABLE Employee
(
    EmpId INT PRIMARY KEY IDENTITY,
    EmpName VARCHAR(100) NOT NULL,
    Position HierarchyID NOT NULL
)

INSERT INTO Employee (EmpName, Position)
VALUES ('CEO', '/'),
    ('COO', '/1/'),
    ('CIO', '/2/'),
    ('CFO', '/3/'),
    ('VP Financing', '/3/1/'),
    ('Accounts Receivable', '/3/1/1/'),
    ('Accountant 1', '/3/1/1/1/'),
    ('Accountant 2', '/3/1/1/2/'),
    ('Accountant 3', '/3/1/1/3/'),
    ('Accounts Payable', '/3/1/2/'),
    ('Accountant 4', '/3/1/2/1/'),
    ('Accountant 5', '/3/1/2/2/'),
    ('DBA', '/2/1/'),
    ('VP of Operations', '/1/1/')

如何找到没有任何子节点的所有行？

我有以下似乎可行的方法，但似乎应该有一种不那么复杂的方式：

select * from (
    select 
        *,  
        case 
            when (select top 1 e.Position from dbo.Employee e where Position.GetAncestor(1) = Employee.Position) is null then 
                cast (0 as bit)
            else 
                cast (1 as bit)
        end as HasDescendants     
    from 
        dbo.Employee
) as managers
where HasDescendants = 0

Answer 1

请参阅另一个堆栈溢出问题： Find all leaf node records using hierarchyid

SELECT A.*
FROM Employee AS A 
LEFT OUTER JOIN Employee AS B
ON A.Position = B.Position.GetAncestor(1)
WHERE B.Position IS NULL;

Answer 2

询问：

SQLFIDDLE示例

SELECT e.*
FROM dbo.Employee e
WHERE NOT EXISTS (SELECT 0
       FROM Employee e2
       WHERE e2.Position.ToString() like e.Position.ToString() + '_%')

结果：

| EMPID |          EMPNAME |    POSITION |
------------------------------------------
|     7 |     Accountant 1 | 122,-42,-80 |
|     8 |     Accountant 2 | 122,-42,-48 |
|     9 |     Accountant 3 | 122,-42,-16 |
|    11 |     Accountant 4 | 122,-38,-80 |
|    12 |     Accountant 5 | 122,-38,-48 |
|    13 |              DBA |     106,-64 |
|    14 | VP of Operations |      90,-64 |