Join 2 tables with distinct - mysql

I have 2 tables, follow and following
follow
+---------+----------------+
| user_id | follow_user_id |
+---------+----------------+
| 1 | 2 |
| 2 | 3 |
| 3 | 4 |
| 100 | 10 |
+---------+----------------+
following
+---------+-------------------+
| user_id | following_user_id |
+---------+-------------------+
| 1 | 2 |
| 3 | 4 |
| 4 | 6 |
| 200 | 500 |
+---------+-------------------+
I want to concat 2 tables without duplicate.
Here is the result that I want.
+---------+----------------+-----------+
| user_id | target_user_id | category |
+---------+----------------+-----------+
| 1 | 2 | follow |
| 2 | 3 | follow |
| 3 | 4 | follow |
| 4 | 6 | following |
| 100 | 10 | follow |
| 200 | 500 | following |
+---------+----------------+-----------+
Condition 1 - Remove duplicated row
Condition 2 - Have to add category column with each table's name
Condition 3 - If category is duplicated, it can be follow or following. it doesn't matter.
Condition 4 - follow_user_id as target_user_id and following_user_id as target_user_id
In this case, should I have to use join? or union?
Any suggestion, very appreciate.
Thanks!

Just use union and group by, the SQL as below:
select
user_id,target_user_id,min(tag) as category
from
(
select user_id,follow_user_id as target_user_id, 'follow' as tag from follow
union
select user_id,following_user_id as target_user_id, 'following' as tag from following
) tmp
group by
user_id,target_user_id
order by
user_id,target_user_id;
+---------+----------------+-----------+
| user_id | target_user_id | category |
+---------+----------------+-----------+
| 1 | 2 | follow |
| 2 | 3 | follow |
| 3 | 4 | follow |
| 4 | 6 | following |
| 100 | 10 | follow |
| 200 | 500 | following |
+---------+----------------+-----------+
6 rows in set (0.00 sec)

Related

How do I join 2 tables to a third one which contains the primary key?

I have 4 tables: the first is the client table, which has customer info, and client_id as an auto-increment primary key.
The second and third are identical in structure: they are used to track attendance to 2 different therapy programs. They each have a primary key, and a client_id column to track the client. One of the fields contains units, which I want to sum.
The last table contains the therapists' info.
Basically I want to extract total amount of units for each client from the two attendance tables.
I have tried LEFT JOINS to no avail. I also tried a UNION ALL, but couldn't get it to sum the units.
This is how the tables look:
client:
+---------------------------------------+
| client_id | f_name | l_name | th_id |
|-----------|----------|--------|-------|
| 1 | sherlock | holmes | 1 |
| 2 | john | watson | 4 |
| 3 | hercule | poirot | 3 |
| 4 | jane | marple | 2 |
+---------------------------------------+
therapist:
+--------------------------+
| th_id | f_name | l_name |
|-------|---------|--------|
| 1 | james | kirk |
| 2 | mr | spock |
| 3 | bones | mccoy |
| 4 | nyota | uhura |
+--------------------------+
attendance it:
+-------------------------------+
| it_id | client_id | units |
|-----------|-----------|-------|
| 1 | 1 | 4 |
| 2 | 1 | 4 |
| 3 | 1 | 0 |
| 4 | 1 | 2 |
| 5 | 4 | 0 |
| 6 | 4 | 4 |
| 7 | 4 | 0 |
| 8 | 4 | 2 |
+-------------------------------+
attendance psr:
+-------------------------------+
| it_id | client_id | units |
|-----------|-----------|-------|
| 1 | 1 | 16 |
| 2 | 1 | 16 |
| 3 | 1 | 0 |
| 4 | 1 | 12 |
| 5 | 4 | 0 |
| 6 | 4 | 14 |
| 7 | 4 | 8 |
| 8 | 4 | 10 |
+-------------------------------+
The result should look like this:
+------------------------------------------------------------+
| client_id | total_units_it | total_units_psr | therapist |
|-----------|----------------|-----------------|-------------|
| 1 | 10 | 44 | james kirk |
| 4 | 6 | 32 | mr spock |
+------------------------------------------------------------+
Please excuse the primitive representations, and please don't ask why the tables are designed like that... ;-) Also, I obviously ignored many other fields which are not relevant to the question, such as dates, etc.
Any advice would be appreciated.
Thanks!
You can't use join or you will create Cartesian product and duplicate the rows.
Instead you do a subquery:
SELECT c.*
, (SELECT SUM(units) FROM attendance_it a WHERE a.client_id = c.client_id ) as total_units_it
, (SELECT SUM(units) FROM attendance psr a WHERE a.client_id = c.client_id ) as total_units_psr
, t.*
FROM client c
JOIN therapist t
ON c.th_id = t.th_id
use group by client_id to get the sum of each client. and no need to use join as you have already the ids in column.

SQL Distinct a column with conditions

I'm working on a query where I need to count distinct CarId row when the column LocationId is not null and get all CarId if its null or 0 but the query that I tried distincts all the CarId even if its null
#LocId int
Select Count(distinct a.CarId) from VehicleDetails a
inner join VehicleDocuments b on a.DocId=b.DocId
left join VehicleShipmentDetails dpg on dpg.VehicleShipmentId= b.VehicleShipmentId
where b.LogicalDelete=0 and a.LogicalDelete=0
and (dpg.LocationId= #LocId or dpg.LocationId= 0 or dpg.LocationId is null)
| ID | CarId | LocationId | DateCreated |
|------+----------------+-----------------+---------------|
| 1 | 1 | 5 | 02/03/2019 |
| 2 | 2 | null | 01/14/2019 |
| 3 | 2 | 0 | 02/03/2019 |
| 4 | 2 | 5 | 12/30/2018 |
| 5 | 4 | 3 | 01/10/2019 |
| 6 | 3 | 5 | 02/14/2019 |
| 7 | 2 | 5 | 03/13/2019 |
Desired output:
| ID | CarId | LocationId | DateCreated |
+------+----------------+-----------------+---------------+
| 1 | 1 | 5 | 02/03/2019 |
| 2 | 2 | null | 01/14/2019 |
| 3 | 2 | 0 | 02/03/2019 |
| 4 | 2 | 5 | 03/13/2019 |
| 5 | 4 | 3 | 01/10/2019 |
| 6 | 3 | 5 | 02/14/2019 |
Current Output
| ID | CarId | LocationId | DateCreated |
+------+----------------+-----------------+---------------+
| 1 | 1 | 5 | 02/03/2019 |
| 2 | 2 | 5 | 01/14/2019 |
| 3 | 4 | 3 | 01/10/2019 |
| 4 | 3 | 5 | 02/14/2019 |
Im getting a count of 4 but i needed to have 6 as the Count
EDIT: My goal is to remove the row to Distinct CarId if the value of the LocationId is Null or 0 but on my Current code, It distincts all CarId that is null,0 and equals to #LocId
You can query something like this, replace your_table by your actual set of data.
SELECT ID, CardId, LocationId, DateCreated
FROM your_table as T
WHERE NOT EXISTS (SELECT *
FROM your_table as T1
WHERE T.ID > T1.ID AND T.CarID = T1.CarID)
In SQL, you can use the statement CASE to manage conditions (just like the "if then else" in other programming languages). In your case this function could help because you have two differents cases to handle.

Query equivalent to two group by's without a subquery?

I'm trying to run a report on User ACL's. We use MYSQL and my we're prohibited from using subqueries for performance reasons. The goal is to turn this:
--------------------------------
| userName | folderID | roleID |
--------------------------------
| gronk | 1 | 1 |
| gronk | 2 | 2 |
| gronk | 4 | 2 |
| tbrady | 1 | 2 |
| jedelman | 1 | 1 |
| jedelman | 2 | 1 |
| mbutler | 1 | 2 |
| mbutler | 2 | 2 |
| bill | 1 | 3 |
| bill | 2 | 3 |
| bill | 3 | 3 |
| bill | 4 | 3 |
--------------------------------
Into this:
------------------------
| Lowest Role | Number |
------------------------
| 1 | 2 |
| 2 | 2 |
| 3 | 1 |
------------------------
I can see how to do it with a subquery. The inner query would do a group by on userName with a min(roleID). Then the outer query would do a group by on the lowest role and count(*). But I can't see how to do it without a subquery.
Also, if it helps I created a SQL Fiddle that has the data above.
I found a solution using a left join:
select UFM.roleID, count(distinct UFM.userName)
from UserFolderMembership UFM
left join UserFolderMembership UFM2 on
UFM.userName = UFM2.userName and
UFM.roleID > UFM2.roleID
where
UFM2.userName is null
group by
UFM.roleID

select sum of product price for every 1 id productcategory

i want to find solution for my query problem. I need to find the SUM of all priceProduct*quantity and separated with each of productcategory. I have already made a query, but it takes longer time to executed it. this is my query,
SELECT
pb.ProductCategoryID,
pb.ProductCategoryDescription,
(SELECT
SUM((SELECT pd.HPP FROM `price details` pd WHERE pd.ProductID = pdt.ProductID ORDER BY pd.PriceDetailID DESC LIMIT 1)*
(SELECT StockProductBallance FROM `stock product` sp WHERE sp.ProductID = pdt.ProductID ORDER BY sp.StockProductID DESC LIMIT 1))
FROM product pdt
WHERE pdt.ProductCategoryID = pb.ProductCategoryID
) AS Total
FROM `product category` pb
GROUP BY pb.ProductCategoryID
this my example table
table product:
+------+-------+
| id_p | id_pc |
+------+-------+
| 1 | 3 |
| 2 | 4 |
| 3 | 3 |
| 4 | 4 |
+------+-------+
table productcategory:
+-------+---------+
| id_pc | pc_name |
+-------+---------+
| 3 | new_pc |
| 4 | old_pc |
+-------+---------+
table price details:
+---------------+------+-----+
| PriceDetailID | id_p | hpp |
+---------------+------+-----+
| 1 | 1 | 100 |
| 2 | 1 | 110 |
| 3 | 1 | 120 |
| 4 | 2 | 200 |
| 5 | 2 | 210 |
| 6 | 2 | 220 |
+---------------+------+-----+
table stockProduct:
+-----------------+------+---------------+
| id_stockProduct | id_p | stockballance |
+-----------------+------+---------------+
| 1 | 1 | 10 |
| 2 | 1 | 11 |
| 3 | 1 | 12 |
| 4 | 2 | 20 |
| 5 | 2 | 21 |
| 6 | 2 | 22 |
+-----------------+------+---------------+
Really need your help guys, for better query..

MySQL complex ORDER BY issue

I have a complicated ordering issue in my query.
Raw, Unordered Data:
+------+--------+-----------+
| id | job_id | action_id |
+------+--------+-----------+
| 1 | 2 | 1 |
| 2 | 2 | 2 |
| 3 | 1 | 1 |
| 4 | 2 | 3 |
| 5 | 4 | 1 |
| 6 | 1 | 2 |
| 7 | 3 | 1 |
| 8 | 3 | 2 |
| 9 | 4 | 2 |
+------+--------+-----------+
Required Ordering:
+------+--------+-----------+
| id | job_id | action_id |
+------+--------+-----------+
| 7 | 3 | 1 |
| 8 | 3 | 2 |
| | | | * blank lines added for clarity,
| 5 | 4 | 1 | not desired in actual data
| 9 | 4 | 2 |
| | | |
| 3 | 1 | 1 |
| 6 | 1 | 2 |
| | | |
| 1 | 2 | 1 |
| 2 | 2 | 2 |
| 4 | 2 | 3 |
+------+--------+-----------+
The theory behind this ordering:
the largest id is the most recently added entry
the most recent id with action_id of 1
followed by the entries with ascending action_ids that have the same job_id
then the next most recent action_id of 1
ad infinitum
EDIT: I'm not able to add columns to the table in order to aid in sorting, as I've seen in some other solutions to ordering questions.
Any help is greatly appreciated!
My best shot is this:
SELECT * FROM tbl
ORDER BY FIND_IN_SET(job_id,
(SELECT GROUP_CONCAT(job_id ORDER BY ID DESC)
FROM tbl WHERE action_id = 1));
I didn't find a way to do it easily, What do you think of the following code :
select c.id, c.job_id, c.action_id
from (select a.id, a.job_id, a.action_id, min(b.id) as related_id
from myTable a
inner join myTable b
on a.job_id=b.job_id
group by a.job_id) c
group by c.id
order by c.related_id desc, c.action_id