get rows and rows from one table SQL server - sql

Question

i have comments table in sql server structured as
CREATE TABLE [dbo].[LS_Commentes](
[CommentId] [int] IDENTITY(1,1) NOT NULL,
[OwnerId] [uniqueidentifier] NULL,
[OwnerName] [nvarchar](50) NULL,
[Email] [nvarchar](250) NULL,
[Date] [nvarchar](15) NULL,
[ParentId] [int] NULL,
[CommentText] [nvarchar](400) NULL,
[ItemId] [int] NULL,
[upVotes] [int] NULL,
[downVotes] [int] NULL,
[isApproved] [bit] NULL,
CONSTRAINT [PK_LS_MsgCommentes] PRIMARY KEY CLUSTERED
(
[CommentId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
and i have sample data like this:
CommentId OwnerId OwnerName Email Date ParentId CommentText ItemId upVotes downVotes isApproved
1 NULL Test Commneter NULL 1/4/2013 NULL test 9 0 0 NULL
2 NULL Test Commneter NULL 1/4/2013 1 test NULL 0 0 NULL
3 NULL Test Commneter NULL 1/4/2013 1 test NULL 0 0 NULL
i want to write one query can get me all rows have itemid =9 and rows have parentid= comment id that selected (because itemid = 9)
look here i can solve it by adding item id 9 to the sub comments too but i just want to know if that could be solved without adding item id to comments and sub comments

Answer 1

I think the following query does what you want:
select *
from ls_comments c
where c.itemID = 9 or
c.parentID in (select c2.commentId from ls_comments c2 where c2.itemId = 9)

Answer 2

Would a recursive Common Table Expression give you the results you're after?
;with cte as
(
--Anchor
select
commentid,
ParentId
from
LS_Commentes
where
ItemId = 9
union all
--Recursive member
select
c.commentId,
c.ParentId
from
LS_Commentes c join cte on c.ParentId = cte.CommentId
)
select * from cte
If you want to include more columns in the results ensure that both parts (the Anchor and recursive member) have identical columns.
Explanation:
The anchor part (the first select) of a recursive query selects all rows where ItemId = 9, the second part uses the existing records in the result to include further records that satisfy it's criters (ParentId = cte.CommentId) this keeps going until nothing more is selected. And then the entire results must be selected at the end (after the CTEs definition)

Answer 3

I think it would be good with an embedded SQL query
SELECT *
FROM `LS_Commentes`
WHERE `ItemId` = '9'
AND `ParentID`= (SELECT `CommentID` FROM `LS_Commentes` WHERE `ItemId` = 9);