I want to show only the top 5 comments for a specific post (Like the post on facebook where people cant comment them).
gbn was kind enough to help figure out that issue by doing the following:
select
*
FROM
tblPost P
OUTER APPLY
(SELECT TOP 5 * FROM tblComment C
WHERE P.id = C.postid
ORDER BY something) inline
But since I'm no sql grand master I would need your help to put that into my real sql statement.
SELECT *
FROM
memberactions INNER JOIN
actions ON memberactions.actionid = actions.id INNER JOIN
members ON memberactions.memberid = members.id LEFT OUTER JOIN
members members_2 INNER JOIN
actioncomments ON members_2.id = actioncomments.memberid INNER JOIN
comments ON actioncomments.commentid = comments.id ON actions.id = actioncomments.actionid
So my question is could you rearrange my sql to put the OUTER APPLY in my real sql statement.
Assuming that my table comments reprensent tblComment and that actioncomments represent the table tblPost
There does not seem to be a need for the member_2 table at all, but this is a faithful representation of what you had (preserving member_2)
SELECT *
FROM memberactions
INNER JOIN actions
ON memberactions.actionid = actions.id
INNER JOIN members
ON memberactions.memberid = members.id
OUTER APPLY (
select top(5) *
FROM actioncomments
inner join comments ON actioncomments.commentid = comments.id
inner join members members_2 ON members_2.id = actioncomments.memberid
WHERE actions.id = actioncomments.actionid
order by comments.id desc) comments
SELECT *
FROM
memberactions
INNER JOIN actions
ON memberactions.actionid = actions.id
INNER JOIN members
ON memberactions.memberid = members.id
LEFT OUTER JOIN members members_2
INNER JOIN actioncomments
ON members_2.id = actioncomments.memberid
OUTER APPLY
(SELECT TOP 5 * FROM comments C
WHERE actioncomments.commentid = comments.id
ORDER BY something)
ON actions.id = actioncomments.actioni
still don't know what you want to order by
Related
I already LEFT JOINed many tables into two sections, but now how do I join these two together?
I am not sure if subquery would work but at least I tried subquery its very confused/
SELECT MoviePerson.PersonId, MoviePerson.PersonFirstName, MoviePerson.PersonLastName, MoviePersonRole.RoleId FROM MoviePerson
LEFT JOIN MoviePersonRole ON MoviePerson.PersonId = MoviePersonRole.PersonId;
select DVD.DVDId, DVD.GenreId, DVD.RatingId, DVD.DVDTitle, DVD.DVDReleasedate, DVD.TheaterReleaseDate, Genre.GenreName, Rating.RatingName,
Rating.RatingDescription
from DVD
LEFT join Genre on DVD.GenreId = Genre.GenreID
LEFT JOIN Rating ON DVD.RatingId = Rating.RatingId
LEFT JOIN MoviePersonRole ON DVD.DVDId =MoviePersonRole.DVDId
;
db<>fiddle
It doesn't look as though you have a column to join on. If you did, you could use the following syntax:
SELECT *
FROM
(
SELECT MoviePerson.PersonId, MoviePerson.PersonFirstName, MoviePerson.PersonLastName, MoviePersonRole.RoleId FROM MoviePerson
LEFT JOIN MoviePersonRole ON MoviePerson.PersonId = MoviePersonRole.PersonId;
) X
INNER JOIN
(
select DVD.DVDId, DVD.GenreId, DVD.RatingId, DVD.DVDTitle, DVD.DVDReleasedate, DVD.TheaterReleaseDate, Genre.GenreName, Rating.RatingName,
Rating.RatingDescription
from DVD
LEFT join Genre on DVD.GenreId = Genre.GenreID
LEFT JOIN Rating ON DVD.RatingId = Rating.RatingId
LEFT JOIN MoviePersonRole ON DVD.DVDId =MoviePersonRole.DVDId
) Y
ON X.column_to_join = y.column_to_join
I am trying to create one single query that will give me a distinct count for both the ActivityID and the CommentID. My query in MS Access looks like this:
SELECT
tbl_Category.Category, Count(tbl_Activity.ActivityID) AS CountOfActivityID,
Count(tbl_Comments.CommentID) AS CountOfCommentID
FROM tbl_Category LEFT JOIN
(tbl_Activity LEFT JOIN tbl_Comments ON
tbl_Activity.ActivityID = tbl_Comments.ActivityID) ON
tbl_Category.CategoryID = tbl_Activity.CategoryID
WHERE
(((tbl_Activity.UnitID)=5) AND ((tbl_Comments.PeriodID)=1))
GROUP BY
tbl_Category.Category;
I know the answer must somehow include SELECT DISTINCT but am not able to get it to work. Do I need to create multiple subqueries?
This is really painful in MS Access. I think the following does what you want to do:
SELECT ac.Category, ac.num_activities, aco.num_comments
FROM (SELECT ca.category, COUNT(*) as num_activities
FROM (SELECT DISTINCT c.Category, a.ActivityID
FROM (tbl_Category as c INNER JOIN
tbl_Activity as a
ON c.CategoryID = a.CategoryID
) INNER JOIN
tbl_Comments as co
ON a.ActivityID = co.ActivityID
WHERE a.UnitID = 5 AND co.PeriodID = 1
) as caa
GROUP BY ca.category
) as ca LEFT JOIN
(SELECT c.Category, COUNT(*) as num_comments
FROM (SELECT DISTINCT c.Category, co.CommentId
FROM (tbl_Category as c INNER JOIN
tbl_Activity as a
ON c.CategoryID = a.CategoryID
) INNER JOIN
tbl_Comments as co
ON a.ActivityID = co.ActivityID
WHERE a.UnitID = 5 AND co.PeriodID = 1
) as aco
GROUP BY c.Category
) as aco
ON aco.CommentId = ac.CommentId
Note that your LEFT JOINs are superfluous because the WHERE clause turns them into INNER JOINs. This adjusts the logic for that purpose. The filtering is also very tricky, because it uses both tables, requiring that both subqueries have both JOINs.
You can use DISTINCT:
SELECT
tbl_Category.Category, Count(DISTINCT tbl_Activity.ActivityID) AS CountOfActivityID,
Count(DISTINCT tbl_Comments.CommentID) AS CountOfCommentID
FROM tbl_Category LEFT JOIN
(tbl_Activity LEFT JOIN tbl_Comments ON
tbl_Activity.ActivityID = tbl_Comments.ActivityID) ON
tbl_Category.CategoryID = tbl_Activity.CategoryID
WHERE
(((tbl_Activity.UnitID)=5) AND ((tbl_Comments.PeriodID)=1))
GROUP BY
tbl_Category.Category;
I am starting with this query, which works fine:
SELECT
C.ContactSys
, ... a bunch of other rows...
FROM Users U
INNER JOIN Contacts C ON U.ContactSys = C.ContactSys
LEFT JOIN UserWatchList UW ON U.UserSys = UW.UserSys
LEFT JOIN Accounts A ON C.AccountSys = A.AccountSys
WHERE
C.OrganizationSys = 1012
AND U.UserTypeSys = 2
AND C.FirstName = 'steve'
Now, I've been given this requirement:
For every visitor returned by the Visitor Search, take ContactSys, get the most recent entry in the GuestLog table for that contact, then return the columns ABC and XYZ from the GuestLog table.
I'm having trouble with that. I need something like this (I think)...
SELECT
C.ContactSys
, GL.ABC
, GL.XYZ
, ... a bunch of other rows...
FROM Users U
INNER JOIN Contacts C ON U.ContactSys = C.ContactSys
LEFT JOIN UserWatchList UW ON U.UserSys = UW.UserSys
LEFT JOIN Accounts A ON C.AccountSys = A.AccountSys
LEFT JOIN (SELECT TOP 1 * FROM GuestLog GU WHERE GU.ContactSys = ????? ORDER BY GuestLogSys DESC) GL ON GL.ContactSys = C.ContactSys
WHERE
C.OrganizationSys = 1012
AND U.UserTypeSys = 2
AND C.FirstName = 'steve'
Only that's not it because that subquery on the JOIN doesn't know anything about the outer tables.
I've been looking at these posts and their answers, but I'm having a hard time translating them to my needs:
SQL: Turn a subquery into a join: How to refer to outside table in nested join where clause?
Reference to outer query in subquery JOIN
Referencing outer query in subquery
Referencing outer query's tables in a subquery
If that is the logic you want, you can use OUTER APPLY:
SELECT C.ContactSys, GL.ABC, GL.XYZ,
... a bunch of other columns ...
FROM Users U JOIN
Contacts C
ON U.ContactSys = C.ContactSys LEFT JOIN
UserWatchList UW
ON U.UserSys = UW.UserSys LEFT JOIN
Accounts A
ON C.AccountSys = A.AccountSys OUTER APPLY
(SELECT TOP 1 gl.*
FROM GuestLog gl
WHERE gl.ContactSys = C.ContactSys
ORDER BY gl.GuestLogSys DESC
) GL
WHERE C.OrganizationSys = 1012 AND
U.UserTypeSys = 2 AND
C.FirstName = 'steve'
I have a database structure (ER diagram below) that has three level of hierarchical data and the fourth level of optional data.
If I write a query to get de-normalized data of three levels - level 1 to level 3 with sample data across three tables shown as below:
When queried, this layout of the data is very straight forward and as expected as below:
Upon running the below query, I get the following output (And I have tried various combinations by clubbing the set of L1 to L4 and moving one L4 out as a another query and then joining the set L1 - L4 etc.) - again this is on the expected lines.
SELECT [Group].GroupId, [Group].GroupName, Category.CategoryId, Category.CategoryName, RLI.RLIId, RLI.RLIText, Comment.CommentId, Comment.CommentText, ManagementResponse.ManagementResponseId,
ManagementResponse.ManagementResponseTest
FROM Category INNER JOIN
[Group] ON Category.GroupId = [Group].GroupId INNER JOIN
RLI ON Category.CategoryId = RLI.CategoryId LEFT OUTER JOIN
ManagementResponse ON RLI.RLIId = ManagementResponse.RLIId LEFT OUTER JOIN
Comment ON RLI.RLIId = Comment.RLIId
However, I need data in the following format - and this is what I am unable to figure out how to get (I don't want the level 4 data to repeat as I add additional level 4 data via left outer joins):
This query will give you the final output:
WITH CommentAndResponse AS (
SELECT Comment.CommentId,
Comment.CommentText,
ManagementResponse.ManagementResponseId,
ManagementResponse.ManagementResponseTest,
COALESCE(Comment.RLIId, ManagementResponse.RLIId) AS RLIId
FROM (
(SELECT Comment.CommentId,
Comment.CommentText,
Comment.RLIId,
ROW_NUMBER() OVER (PARTITION BY Comment.RLIId ORDER BY Comment.CommentId) AS CommentRowNumber
FROM Comment) AS Comment
FULL JOIN
(SELECT ManagementResponse.ManagementResponseId,
ManagementResponse.ManagementResponseTest,
ManagementResponse.RLIId,
ROW_NUMBER() OVER (PARTITION BY ManagementResponse.RLIId ORDER BY ManagementResponse.ManagementResponseId) AS ManagementResponseRowNumber
FROM ManagementResponse) AS ManagementResponse
ON Comment.CommentRowNumber = ManagementResponse.ManagementResponseRowNumber AND Comment.RLIId = ManagementResponse.RLIId )
)
SELECT [Group].GroupId, [Group].GroupName, Category.CategoryId, Category.CategoryName, RLI.RLIId, RLI.RLIText, CommentAndResponse.CommentId, CommentAndResponse.CommentText, CommentAndResponse.ManagementResponseId, CommentAndResponse.ManagementResponseTest
FROM [Category]
INNER JOIN [Group] ON Category.GroupId = [Group].GroupId
INNER JOIN [RLI] ON Category.CategoryId = RLI.CategoryId
LEFT OUTER JOIN [CommentAndResponse] ON RLI.RLIId = CommentAndResponse.RLIId
You need to specify that Comment.CommentId is equal to ManagementResponse.ManagementResponseId or either is null. That can be part of a JOIN or a separate WHERE
SELECT [Group].GroupId, [Group].GroupName, Category.CategoryId, Category.CategoryName, RLI.RLIId, RLI.RLIText, Comment.CommentId, Comment.CommentText, ManagementResponse.ManagementResponseId,
ManagementResponse.ManagementResponseTest
FROM [Category]
INNER JOIN [Group] ON Category.GroupId = [Group].GroupId
INNER JOIN [RLI] ON Category.CategoryId = RLI.CategoryId
LEFT OUTER JOIN [ManagementResponse] ON RLI.RLIId = ManagementResponse.RLIId
LEFT OUTER JOIN [Comment] ON RLI.RLIId = Comment.RLIId
WHERE ManagementResponse.ManagementResponseId = Comment.CommentId OR ManagementResponse.ManagementResponseId IS NULL OR Comment.CommentId IS NULL
This assumes that those IDs begin equal is the relationship you want to model. The example data seems to show this, but it could be a coincidence of how you assembled the example. Alternatively, if there is no relationship between Comment and ManagementResponse besides RLIId, something like
WITH CommentAndResponse AS (
SELECT Comment.CommentId, Comment.CommentText, ManagementResponse.ManagementResponseId, ManagementResponse.ManagementResponseTest,
COALESCE(Comment.RLIId, ManagementResponse.RLIId) AS RLIId,
ROW_NUMBER() OVER (ORDER BY Comment.CommentId, ManagementResponse.ManagementResponseId, PARTITION BY Comment.RLIId, ManagementResponse.RLIId) AS rn
FROM Comment
FULL JOIN ManagementResponse ON Comment.RLIId = ManagementResponse.RLIId)
SELECT [Group].GroupId, [Group].GroupName, Category.CategoryId, Category.CategoryName, RLI.RLIId, RLI.RLIText, CommentAndResponse.CommentId, CommentAndResponse.CommentText, CommentAndResponse.ManagementResponseId, CommentAndResponse.ManagementResponseTest
FROM [Category]
INNER JOIN [Group] ON Category.GroupId = [Group].GroupId
INNER JOIN [RLI] ON Category.CategoryId = RLI.CategoryId
LEFT OUTER JOIN [CommentAndResponse] ON RLI.RLIId = CommentAndResponse.RLIId AND CommentAndResponse.rn = 1
I'm currently working with database, but I've got stuck with a select query.
However, I'm not database expert.
The query should return the data from a table that has two relationships of many to many.
This is my tables Diagram that would shows the concept of my question
The Select Query should View three columns, which are VidTbl.Name, ActorTbl.Name and SubTitelTbl.name.
So, I've read and search in the Internet and I've given tries
First try
SELECT
VidTbl.NAME AS Video_Titel_Name,
ActorTbl.NAME AS Actor_Name
FROM ActorInVid
INNER JOIN VidTbl
ON VidTbl.Id = ActorInVid.FKVidId
INNER JOIN ActorTbl
ON ActorTbl.Id = ActorInVid.FKActorId
UNION all
SELECT
VidTbl.NAME AS Video_Titel_Name,
SubTitelTbl.NAME AS SubTitel_Langu
FROM SubTitelInVid
INNER JOIN VidTbl
ON VidTbl.Id = SubTitelInVid.FKVidId
INNER JOIN SubTitelTbl
ON SubTitelTbl.Id = SubTitelInVid.FKSTId
The Result I've got, it was wrong
Then I tried another way to solve this problem, but again I've got another error
second try
SELECT Temp1.*
From (SELECT VidTbl.Id AS Video_Id,
VidTbl.NAME AS Video_Titel_Name,
ActorTbl.NAME AS Actor_Name
FROM ActorInVid
INNER JOIN VidTbl
ON VidTbl.Id = ActorInVid.FKVidId
INNER JOIN ActorTbl
ON ActorTbl.Id = ActorInVid.FKActorId) AS Temp1
SELECT Temp2.*
FROM (SELECT VidTbl.Id AS Video_Id,
SubTitelTbl.NAME AS SubTitel_Langu
FROM SubTitelInVid
INNER JOIN VidTbl
ON VidTbl.Id = SubTitelInVid.FKVidId
INNER JOIN SubTitelTbl
ON SubTitelTbl.Id = SubTitelInVid.FKSTId) AS Temp2
SELECT *
FROM VidTbl
INNER JOIN Temp1
on Temp1.Video_Id = VidTbl.Id
INNER JOIN Temp2
on Temp2.Video_Id = VidTbl.Id
The error, I've got in the last select that was wrong
Thanks a lot for your help any ways
I wish that my question is clear and useful
Thanks again.
You are close. This should work...
SELECT
VidTbl.Name,
ActorTbl.Name,
SubTitelTbl.name
FROM VidTbl
INNER JOIN ActorInVid ON VidTbl.Id = ActorInVid.FKVidId
INNER JOIN ActorTbl ON ActorTbl.Id = ActorInVid.FKActorId
INNER JOIN SubTitelInVid ON VidTbl.Id = SubTitelInVid.FKVidId
INNER JOIN SubTitelTbl ON SubTitelTbl.Id = SubTitelInVid.FKSTId
SELECT DISTINCT vt.Name, at.Name, st.Name
FROM VidTbl vt
JOIN ActionInVid aiv ON aiv.VidId = vt.Id
JOIN SubtitleInVid siv ON siv.VidId = vt.Id
JOIN ActorTbl at ON at.Id = aiv.ActorId
JOIN SubTitleTbl st ON st.Id = siv.STId