SQL

how to find all children of a record with only parent ID in sql

DECLARE @Table TABLE(
        ID INT,
        ParentID INT,
        NAME VARCHAR(20)
)

INSERT INTO @Table (ID,ParentID,[NAME]) SELECT 1, NULL, 'A'
INSERT INTO @Table (ID,ParentID,[NAME]) SELECT 2, 1, 'B-1'
INSERT INTO @Table (ID,ParentID,[NAME]) SELECT 3, 1, 'B-2'
INSERT INTO @Table (ID,ParentID,[NAME]) SELECT 4, 2, 'C-1'
INSERT INTO @Table (ID,ParentID,[NAME]) SELECT 5, 2, 'C-2'


DECLARE @ID INT

SELECT @ID = 2

;WITH ret AS(
        SELECT  *
        FROM    @Table
        WHERE   ID = @ID
        UNION ALL
        SELECT  t.*
        FROM    @Table t INNER JOIN
                ret r ON t.ParentID = r.ID
)

SELECT  *
FROM    ret

sql - Find all children who are not parent

WHERE ID NOT IN (SELECT ParentID FROM [SMD].[dbo].[ProposalFollowUp])

sql - Find all children who are not parent

SELECT ID, ParentID 
FROM [SMD].[dbo].[ProposalFollowUp] t1
WHERE NOT EXISTS
(
   SELECT 1 FROM [SMD].[dbo].[ProposalFollowUp] t2
   WHERE t2.ParentID = t1.ID
)