I have 3 tables that I need to JOIN, but I'm having difficulty getting the right result because I need information from more than 1 column. I wish to get all users that are available and has the status = 1. In addition, get both types 1 and 3. With users listed as type 3, I need to join with the other table (by user id) to get only users with a specific specialty listed on the other table.
My tables are similar to these:
users
id | status | availability | type
1 | 1 | 1 | 1
2 | 1 | 0 | 1
3 | 0 | 0 | 2
4 | 1 | 1 | 3
5 | 1 | 1 | 3
specialties
id | type
1 | 1
2 | 2
3 | 3
4 | 43
My relation table would look like this:
rel_users_specialties
id | id_user | id_specialty
1 | 1 | 29
2 | 2 | 3
3 | 4 | 3
4 | 5 | 3
My query would be:
SELECT *
FROM users u
JOIN rel_users_specialties r ON r.id_user = u.id
WHERE u.status = 1
AND u.disponibilidade = 1
AND r.id_specialty = 3
AND (u.type = 3 OR u.type = 1)
My expected result would be the following users (by id)
1, 4 and 5 (exclude user number 2 because of the availability = 0) and Although the user 1 has a specialty different than 3 it also has a type 1 (type one here would be a constant, regardless of the specialty selected).
Appreciate the help!
Set the conditions like this:
SELECT u.*
FROM users u INNER JOIN rel_users_specialties r
ON r.id_user = u.id
WHERE u.status = 1 AND u.availability = 1
AND ((u.type = 1) OR (u.type = 3 AND r.id_specialty = 3))
Or without a join:
SELECT u.*
FROM users u
WHERE u.status = 1 AND u.availability = 1
AND (
(u.type = 1)
OR
(u.type = 3 AND EXISTS(SELECT 1 FROM rel_users_specialties r WHERE r.id_user = u.id AND r.id_specialty = 3))
)
See the demo.
Related
I have three tables, two of which are relevant for this question. Users, Things, User_to_thing
Users
ID | Name | Active
-------------------
1 | Joe | 1
2 | Jack | 1
3 | Tom | 1
4 | Harry | 0
5 | Stan | 1
6 | Bob | 1
User_to_thing
Thing ID | User ID | Status
---------------------------
3 | 1 | 1
3 | 2 | 2
3 | 5 | 1
4 | 1 | 3
4 | 2 | 2
I'm trying to create a query where I can select all the active users in the users table and have a column where I can see the status for "thing 3" from the User_to_thing table while also sorting results so that the nulls come at the end. So the result would be something like:
User ID | Status
----------------
1 | 1
2 | 2
5 | 1
3 | NULL
6 | NULL
What I have so far for a query is the following:
SELECT u1.id, u1.name, user_to_thing.status
FROM users u1
LEFT JOIN user_to_thing ON u1.id = user_to_thing.user_id
WHERE u1.active = 1
OR user_to_thing.event_id = 62
ORDER BY (CASE WHEN user_to_thing.status = 1 THEN 1
WHEN user_to_thing.status = 2 THEN 2
ELSE 3 END)
What I'm getting as a result is the following:
User ID | Status | Thing ID
---------------------------
1 | 1 | 3
1 | 3 | 4
2 | 2 | 3
2 | 2 | 4
5 | 1 | 3
3 | NULL | NULL
6 | NULL | NULL
I'm not sure how to limit it to just thing #3 while also getting a list of all active users. Any guidance would be appreciated.
It looks like the following should work for you, grouping to remove duplicates and ordering based on null
select u.Id as UserId, t.status
from users u
left join User_to_thing t on t.UserID = u.id
where u.active = 1
group by u.Id, t.Status
order by case when status is null then 1 else 0 end, u.Id
Based on your revised data, you can amend slightly
select u.Id UserId, Min(t.status) Status
from users u
left join User_to_thing t on t.UserID=u.id
where u.active=1
group by u.Id
order by case when Min(t.status) is null then 1 else 0 end, u.Id
I'm trying write a query:
SELECT id FROM users WHERE status = 3
But if this sample returns an empty response, then I need instead to select the id where status = 4, and if it returns empty again, where status = 5.
How can I write a single query to solve this?
I think you simply want:
SELECT id
FROM users
WHERE status >= 3
ORDER BY status asc
LIMIT 1;
If you want multiple users:
SELECT u.id
FROM users u
WHERE u.status = (SELECT MIN(u2.status)
FROM users u2
WHERE u2.status >= 3
);
If you have a fixed list you want to test, you can also use:
select u.id
from users u
where u.status = 3
union all
select u.id
from users u
where u.status = 4 and
not exists (select 1 from users u2 where u2.status in (3))
union all
select u.id
from users u
where u.status = 5 and
not exists (select 1 from users u2 where u2.status in (3, 4));
You can use OR condition or use IN operator
SELECT id FROM users WHERE status = 3 or status = 3 or status = 5
or
SELECT id FROM users WHERE status IN (3,4,5)
I will use the case statement in the where clause:
select id
from users
where status = case when status = 3 and id is null then 4
when status = 4 and id is null then 5
else 3
end
Let me know if you have any question.
Assuming that your table look like this:
+----+--------+
| id | status |
+----+--------+
| 1 | 3 |
| 1 | 4 |
| 1 | 5 |
| 3 | 3 |
| 3 | 4 |
| 4 | 4 |
| 4 | 5 |
| 5 | 5 |
+----+--------+
And based on your condition where you want to see the lowest status first for each id, you can use MIN() operator.
So, from your original query:
SELECT id,MIN(status) FROM users GROUP BY id;
Then you'll get a result like this:
+----+-------------+
| id | MIN(status) |
+----+-------------+
| 1 | 3 |
| 3 | 3 |
| 4 | 4 |
| 5 | 5 |
+----+-------------+
I have table user_answers :
id | quiz_id | user_id | question_id | choosen_answer_id |
1 | 1 | 2 | 1 | 5 |
2 | 1 | 2 | 2 | 6 |
3 | 1 | 2 | 3 | 7 |
4 | 1 | 3 | 1 | 5 |
5 | 1 | 3 | 2 | 8 |
6 | 1 | 3 | 3 | 9 |
I want to cont how many correct answers (same choosen_answer_id for same question_id ) has user with user_id = 3 compared with user_id = 2 on same quiz_id
In this example I should receive 1 because user with user_id = 3 answered correct only on question with question_id=1 (for user_id = 2, question_id = 1 choosen_answer_id = 5 and for user_id = 3, question_id = 1 choosen_answer_id = 5`).
Thanks
I understand that you are willing to count for how many questions both users have given the same answer. You could self-join the table as follows :
SELECT COUNT(*) AS number_of_identical_answers
FROM user_answers ua2
INNER JOIN user_answers ua3
ON ua3.user_id = 3
AND ua3.quiz_id = ua2.quiz_id
AND ua3.question_id = ua2.question_id
AND ua3.choosen_answer_id = ua2.choosen_answer_id
WHERE ua2.user_id = 2
If you want to display the joined records instead of counting them, you can change COUNT(*) to a list of columns from tables ua2 (answers of user 2) and ua3 (answers of user 3).
select user_id, count(*)
from table1 t1
join (select *from table1 where user_id = 2) t2
on t2.question_id = t1.question_id
where t2.choosen_answer_id = t1.choosen_answer_id
group by t1.user_id
I have a table Follow, which only holds records of which UserID follows which TargetID.
If asked for user A:
If neither A or B are following eachother, they have status of 0 for unrelated, and aren't included in the results.
If user A is following B but not vice versa, B has status 1 for
being followed.
If user B is following A but not vice versa, B has
status 2 for being a follower.
If A is following B, and B following
A, B has status of 3 for being a friend.
How can I, in a single MySQL query, get the relationship status for a given user and all its relationships above status 0?
Example:
Users:
+----+-------+
| id | Name |
+----+-------+
| 1 | Bob |
| 2 | Steve |
| 3 | Scott |
| 4 | Mary |
+----+-------+
Follow:
+----+--------+----------+
| id | UserID | TargetID |
+----+--------+----------+
| 1 | 1 | 2 |
| 2 | 1 | 3 |
| 3 | 2 | 1 |
| 4 | 4 | 1 |
+----+--------+----------+
Expected result for user 1:
+----------+--------+-------+
| TargetID | Status | Name |
+----------+--------+-------+
| 2 | 3 | Steve | (friend)
| 3 | 1 | Scott | (following)
| 4 | 2 | Mary | (follower)
+----------+--------+-------+
You can use subqueries as illustrated below:
-- FOR USER 1
SELECT A.id TargetID,
SUM(IFNULL((SELECT 1 C FROM Follow B WHERE B.UserID=1 AND B.TargetID=A.id),0) +
IFNULL((SELECT 2 C FROM Follow D WHERE A.id=D.UserID AND D.TargetID=1), 0)) Status
, A.name
FROM (SELECT * FROM Users WHERE ID<>1) A
GROUP BY A.id, A.Name
HAVING Status>0; -- for a compact result
-- NOW GLOBALLY
SELECT A.UserID, A.id TargetID,
SUM(IFNULL((SELECT 1 C FROM Follow B WHERE B.UserID=A.UserID AND B.TargetID=A.id),0) +
IFNULL((SELECT 2 C FROM Follow D WHERE A.id=D.UserID AND D.TargetID=A.UserID), 0)) Status
, A.name
FROM (SELECT E.id UserID, F.* FROM Users E JOIN Users F ON E.id<>F.id) A
GROUP BY A.UserID, A.id, A.Name
HAVING Status>0 -- for a compact result
ORDER BY A.UserID;
See DEMO on SQL Fiddle
I have not tried this but try something among the lines of:
Select t.targetid as TargetId,
IF (
(select count(id) from follow where
follow.Userid = f.target.id and follow.target_id = u.id) > 1,
-- mean’s the target is following user 1
(IF (
(select count(id) from follow where
follow.Userid = u.id and follow.target_id = f.targetid) > 1, 3, 2))
-- if user1 is following aswell, then its a friend, else its a follower
, 1)
-- else means its a following
as status,
u.name as Name from follow f
inner Join users u on u.id = f.targetid
where u.id = 1
Inner join to select user 1's relations (if it doesn't exist, they aren't related)
If there is a record, means they are one of 3:
I have the following tables.
Table : types
--------------------
id | type
--------------------
1 | AA
--------------------
2 | BB
--------------------
3 | AA
--------------------
4 | BB
--------------------
Table : users
--------------------
id | username
--------------------
1 | abc
--------------------
2 | bcd
--------------------
3 | cde
--------------------
4 | def
--------------------
Table : methods
---------------------------------
id | user_id | details | type_id
---------------------------------
1 | 1 | detail_1 | 1
---------------------------------
2 | 1 | detail_2 | 3
---------------------------------
3 | 1 | detail_3 | 1
---------------------------------
4 | 1 | detail_4 | 3
---------------------------------
5 | 2 | detail_3 | 1
---------------------------------
6 | 2 | detail_5 | 2
---------------------------------
7 | 2 | detail_6 | 4
---------------------------------
8 | 2 | detail_2 | 3
---------------------------------
9 | 1 | detail_2 | 3
---------------------------------
10 | 1 | detail_2 | 3
---------------------------------
Desired Result :
---------------------------------------------------
UserName | No_of_AA_details | No_of_BB_details |
---------------------------------------------------
abc | 4 | 0 |
---------------------------------------------------
bcd | 2 | 2 |
---------------------------------------------------
I need to get the count of distinct details based on the type from types table.
I have tried this queries but max I am getting is all the counts and not the distinct values.
SELECT u.username,
CASE WHEN t.type = 'AA' THEN count(distinct m.details) END AS No_of_AA_details,
CASE WHEN t.type = 'BB' THEN count(distinct m.details) END AS No_of_BB_details
FROM users as u inner join methods as m on u.id = m.user_id inner join types as t on t.id = m.type_id
GROUP BY m.user_id
SELECT u.username,
SUM(t.type = 'AA') AS No_of_AA_details,
SUM(t.type = 'AA') AS No_of_BB_details
FROM users as u inner join methods as m on u.id = m.user_id inner join types as t on t.id = m.type_id
GROUP BY m.user_id
Any suggestions are welcome.
I can't test it right know but i think you had a good idea, can you try :
SELECT u.username,
m.user_id,
CASE
WHEN t.type = 'AA' THEN 1
ELSE 0
END AS No_of_AA_details,
CASE
WHEN t.type = 'BB' THEN 1
ELSE 0
END AS No_of_BB_details
FROM users as u
INNER JOIN methods as m on u.id = m.user_id
INNER JOIN types as t on t.id = m.type_id
and now you just need to do the sum :
SELECT u.username,
m.user_id,
SUM (CASE
WHEN t.type = 'AA' THEN 1
ELSE 0
END ) AS No_of_AA_details,
SUM (CASE
WHEN t.type = 'BB' THEN 1
ELSE 0
END ) AS No_of_BB_details
FROM users as u
INNER JOIN methods as m on u.id = m.user_id
INNER JOIN types as t on t.id = m.type_id
GROUP BY u.username, m.user_id