I got 3 tables, Users, courses and course realation tables. I want to get users who aren't on specific course. So I figure I need somehow merge 2 selects with right join. How could I make one select from 2 selects?
SELECT ID, NAME, LASTNAME, ROLE FROM COURSERELATION JOIN USERS ON
ID_USER = ID WHERE ID_COURSE = ?
RIGTH JOIN
SELECT ID, NAME, LASTNAME, ROLE from COURSERELATION JOIN USERS ON
ID_USER = ID WHERE ID_COURSE != ?
You need to extract users for which it doesn't exist a record of that user for the specific course. You can filter the rows using a NOT EXISTS clause over a subquery.
Please try below query:
SELECT u.ID,
u.NAME,
u.LASTNAME,
u.ROLE
FROM USERS u
WHERE NOT EXISTS (SELECT 1
FROM COURSERELATION s
WHERE s.id_user = u.id
AND s.id_course = 'YOUR_COURSE_ID_HERE' )
Related
I am trying to get a list of users that only exist in a single group and no other groups. The users can be in multiple groups.
The group I want to get users in has an ID of 20064212 and belongs to the acc_id 200640
There are three tables involved:
Users
USER_PK_ID,
ACC_ID,
Active,
Deleted
USER_GROUP_USER
GROUP_ID, USER_PK_ID
USER_GROUP
ID,
ACC_ID,
DESCRIPTION,
ACTIVE
I can get all the users in the group with the fallowing query but it does not exclude users that exist in other groups also.
SELECT DISTINCT (U.USER_PK_ID)
FROM USER_GROUP_USER U
JOIN USERS US ON US.USER_PK_ID = U.USER_PK_ID
WHERE GROUP_ID = 20064212
AND US.acc_id = 200640
AND US.DELETED = 'N'
I have tried various queries but they always seem to return users that also exist in other groups
SELECT DISTINCT (U.USER_PK_ID)
FROM USER_GROUP_USER U
JOIN USERS US ON US.USER_PK_ID = U.USER_PK_ID
WHERE GROUP_ID = 20064212
AND US.acc_id = 200640
AND US.DELETED = 'N'
AND GROUP_ID NOT IN (
SELECT ID
FROM USER_GROUP
WHERE acc_id = 200640
AND ID != 20064212)
Hoping I parsed your text correctly; this SQL returns users with ACC_ID= 200640 and DELETE='N' and that are member of group with ID 20064212, but not member of any other group.
select u.user_pk_id
from users u
join user_group_user ugu on (u.user_pk_id = ugu.user_pk_id)
join user_group ug on ugu.group_id=ug.id
where ugu.group_id=20064212
and u.acc_id=200640
and u.deleted='N'
and not exists (
select null
from user_group_user ugu2
where ugu2.group_id != ugu.group_id
and ugu.user_pk_id = ugu2.user_pk_id
);
I have 3 tables user, student_data, teacher_data. A user can be either student or a teacher. If it is the teacher I want to join user and teacher_data. And if it is a student then I want to join user with student_data.
How I can do this join with the condition.
I'd combine the two data tables in a sub-query, and then join the users to that.
SELECT
*
FROM
usr u
LEFT JOIN
(
SELECT user_id, datum, xxx, NULL AS yyy FROM student_data
UNION ALL
SELECT user_id, datum, NULL, yyy FROM teacher_data
)
d
ON d.user_id = u.id
https://dbfiddle.uk/?rdbms=oracle_21&fiddle=9b801ea739d42fe50c00ef4e17eaf143
NOTES:
The columns selected from the two data tables must match
Any unmatched columns must either be skipped or filled with NULL
Please don't call a table user, it's a reserved keyword and Oracle won't allow it.
You can write it like this:
select u.user_id,
s.student_id,
t.teacher_id
from usr u
left join student_data s on u.user_id=s.student_id
left join teacher_data t on u.user_id=t.teacher_id
where s.student_id is not null or t.teacher_id is not null
order by u.user_id
For every user_id check if he is a student or teacher, if he is student get his student column values else null, if he is a teacher get his teacher column values else null.
maybe try a union - something like this
select user_id, user_other_stuff
from user, student_data
where user.user_id = student_data.user_id
UNION
select user_id, user_other_stuff
from user, teacher_data
where user.user_id = teacher_data.user_id
I have two tables, like that:
users(id, name)
phones(user_id, number)
I'd like to select all user's names that are in more than three rows in the table phones. How can I do that?
Join the tables and add a having clause that limits the results returned by the count of the user_ids
select name,
count(user_id)
from users u
join phones p
on u.id = p.user_id
group by name
having count(user_id) > 3
SQL Fiddle: http://sqlfiddle.com/#!2/c5516/2
select name from user
join phones on id = user_id
Group By user_id
Having Count(number) > 3
Considering these two tables:
Position(positionid, positiontext, reportstopositionid)
User(userid, positionid)
How can I check if a user has any subordinates in one query?
Is it even possible?
A subordinate:
user (a) with positionid has at least one or more subordinates if there exists any users (b) with the positionid of user (a) as reportstopositionid to users (b) corresponding positionid
This will return users who have subordinates:
SELECT *
FROM User u
WHERE EXISTS (
SELECT 1
FROM Position p
WHERE p.reportstopositionid = u.positionid
)
how about this one?
SELECT DISTINCT a.*
FROM user a
INNER JOIN position b
ON a.userID = b.reportstopositionID
the records returned by this query are those which has matching IDs userid on position table at column reportstopositionID
I think you want to do this with a where clause:
select u.*
from user u
where u.positionId in (select reportstopositionid from position p)
This gets the list of users who match, without duplicates.
I have 3 tables in my system: Courses, Scores and Users. Scores is a table which has the test results for each course and each user. So I have the ScoreID, The CourseID the UserID and the Score itself.
I want to show in some page the list of courses that the user didn't finished yet. So I want it to show all the courses excluding those the user has records in the Scores table (meaning he already has finished it).
How do I exclude the rows from a SELECT statement when certain CourseID and UserID match at the same time?
Assuming that this is for just one user, Mark Bannister's answer can be simplified a little...
SELECT
*
FROM
Courses
WHERE
NOT EXISTS (SELECT * FROM Scores WHERE CourseID = Courses.CourseID AND UserID = #userID)
Try:
select *
from Courses c
cross join Users u
where not exists
(select null from Scores s where s.CourseID = c.CourseID and s.UserID = u.UserID)
select *
from Courses
where not exists
(
select null from Scores where Scores.CourseID = Courses.CourseID
and Scores.UserID = Courses.UserID
)
Assuming you are using SQL Server you can
CROSS APPLY the courses and users, creating every possible combinations of courses and users
use NOT EXISTS to filter out those records where a UserID exists.
SQL Statement
SELECT *
FROM Courses c
CROSS APPLY Users u
WHERE NOT EXISTS (
SELECT *
FROM Scores
WHERE UserID = u.UserID
AND ScoreID = c.ScoreID
)
In case you are using any other DBMS, following should work on most DBMS's
SELECT *
FROM Courses AS c
, Users AS u
WHERE NOT EXISTS (
SELECT *
FROM Scores
WHERE UserID = u.UserID
AND ScoreID = c.ScoreID
)