Getting next and previous record in a join - php

I am currently using this query to select a media record in my PHP application and get the associated user data (if available):
SELECT media.*,
user.*
FROM media_table AS media
LEFT JOIN user_table AS user ON
(user.user_id = media.user_id)
WHERE media.media_id = {$mediaId}
What I'm interested in doing is selecting media.* for the next available media_table record and the previous media_table record. I could do this based on the media_id itself (media_table.media_id is auto increment) or there are other columns available such as media_date (this may be more accurate - it's an INT column in epoch time format).
And I would like to do this (if possible) via a join so I don't have to run multiple queries.
It reminds me of this answer: https://stackoverflow.com/a/1446831/1593325
It gave me some idea, but I couldn't get it to work (unless I ran separate queries).
Any help is much appreciated. Thank you so much for your time.

If you wish to get all the 3 rows at the same time, you can modify your WHERE clause to accommodate your requirements. The modified query would be :
SELECT media.*,
user.*
FROM media_table AS media
LEFT JOIN user_table AS user ON
(user.user_id = media.user_id)
WHERE (media.media_id = {$mediaId}
or media.media_id = ({$mediaId}-1)
or media.media_id = ({$mediaId}+1))
Update :
In that case you can use the query as
SELECT media.*,
user.*
FROM media_table AS media
LEFT JOIN user_table AS user ON
(user.user_id = media.user_id)
WHERE (media.media_id = {$mediaId}
or media.media_id = (SELECT MIN(media_id ) FROM media_table
where media_id > {$mediaId})
or media.media_id = (SELECT MAX(media_id ) FROM media_table
where media_id < {$mediaId})
)

Related

MYSQL PHP select the opposite of a query

I have two tables.
One table has everything I need including a cardId(PK)
The other name is a user type table. This table stores the userId and the cardId(FK).
SELECT ci.cardId, ci.year, ci.name, ci.number
FROM USERCARDS uc
INNER JOIN CARDINDEX ci ON uc.cardId = ci.cardId
WHERE uc.userId = 'USER_ID'
So for this query, it will display the cardId, year, name, and number from the CARDINDEX. It will only display the cards that the user has saved in USERCARDS.
I want to do the opposite. If a user is looking at, lets just say, 5 cards, but the CARDINDEX has 50 cards, this query will display the information for the five cards. However, for a new query, I would want to show the remaining 45 cards. Basically, they cant add a card they already are following.
I tried to have uc.cardId != ci.cardId but that didn't work. Im kind of lost.
You can phrase this as a LEFT JOIN:
SELECT ci.cardId, ci.year, ci.name, ci.number
FROM CARDINDEX ci LEFT JOIN
USERCARDS uc
ON uc.cardId = ci.cardId AND
uc.userId = 'USER_ID'
WHERE uc.cardID IS NULL;
Alternatively, you could write this using `NOT EXISTS:
SELECT ci.cardId, ci.year, ci.name, ci.number
FROM CARDINDEX ci
WHERE NOT EXISTS (SELECT 1
FROM USERCARDS uc
WHERE uc.cardId = ci.cardId AND
uc.userId = 'USER_ID'
);

What join to use

I have two tables, one for registered users and one to store votes.
We are logging in with registrants.id and registrants.zipcode. Once they vote their votes are inserted into the votes table, along with their Registration ID.
Im trying to right a select statement that returns a record that will select all the records for Matched ID and Zipcode, but the ID is not in the Votes.voter column. i have tried all kinds of variations of all the joins i can think of. is it something simple i am missing.
SELECT * FROM registrants
LEFT JOIN votes on registrants.id = votes.voter
WHERE registrants.id = 1 AND registrants.zipcode = 46706 and votes.voter <> 1
Perhaps a not exists query:
select * from registrants
where registrants.zipcode = '46706'
and not exists (select 1 from votes where registrants.id = votes.voter)

Distinct Values from MySQLi Query

I am trying to only show unique userIds (userIds are (0,1,2,3,4,5,6,7,8,9 etc...) for the query I am running. I tried using DISTINCT in my query, but it only shows me unique values of the rows that have 2 or more of the same userId.
Is there a way I can use php to only show the unique values. My weak points are arrays and it makes it more complicated because its using data from a MySQLi query.
Example right now I have with the query now (lets say its GROUP BY rentPaid DESC and the rent total is 800.00 for all users):
userID rentPaid rentMonth
2--------800.00------April
1--------500.00------April
3--------400.00------April
3--------400.00------April
1--------200.00------April
1--------100.00------April
Example desired output:
userID rentPaid rentMonth
2--------800.00------April
1--------500.00------April
3--------400.00------April
Can I do this with MYSQL because I tried DISTINCT and it wouldn't work, how about PHP?
Query:
SELECT
properties.*,
leases.*,
users.userId, users.primaryPhone,
CONCAT(users.userFirstName,' ',users.userLastName) AS user,
admins.adminName, payments.*
FROM
properties
LEFT JOIN leases ON properties.propertyId = leases.propertyId
LEFT JOIN assigned ON properties.propertyId = assigned.propertyId
LEFT JOIN admins ON assigned.adminId = admins.adminId
LEFT JOIN users ON properties.propertyId = users.propertyId
LEFT JOIN payments ON properties.propertyId = payments.propertyId
WHERE
payments.rentMonth = '$currentMonth' AND
payments.rentYear = '$currentYear'
Edit: Please excuse my formatting, this is my first post.
Edit: Added query....its long, but works lol. I only want unique userIds (no double or triple userIds etc...)
I suspect this is what you want:
SELECT userID, MAX(rentPaid) AS maxRentPaid, rentMonth
FROM yourTable
WHERE rentMonth = "April"
GROUP BY userID
ORDER BY maxRentPaid

MySQL very simple join example requested with subtable

I keep falling back into questions with MySQL joining.
And I would like to request a very simple example I could use to continue my journey of understanding learning the MySQL syntax.
Let's say I got the following table's
test_testtable
testtable_id
testtable_name
testtable_user
testtable_option
testtable_textfield
test_testlink
testlink_id
testlink_link
testlink_address
test_address
address_id
address_name
address_phone
address_email
address_street
address_city
address_zip
I would like to make a selection like :
SELECT * (lets say I would define the fields) FROM `test_testable`
JOIN `test_testtable`.`testtable_id` = `test_testlink`.`testlink_link`
AND
JOIN `test_testlink`.`testlink_addres` = `test_address`.`address_id`
WHERE `user_id` = 5
Hence the linking structure is like:
test_testtable.testtable_id = leading
table test_testlink is a table to link the table test_testtable and test_address
And linking table test_testlink uses the field testlink_link to link to the table test_testtable, and uses the field testlink_address to link to the table test_address
This does not work. FOR ME.. Since I continuously seem to fail of catching the correct syntax logic.
So I hope that someone could give me a small example of how to correctly implement such a simple yet critical query!
TIAD!!
A general approach :
SELECT table1.* FROM table1
JOIN table2 ON table2.id_table1 = table1.id
JOIN table3 ON table3.id_table2 = table2.id
WHERE table1.id = 10
For your purpose :
SELECT * (lets say I would define the fields) FROM `test_testable`
JOIN `test_testlink` ON `test_testtable`.`testtable_id` = `test_testlink`.`testlink_link`
JOIN `test_address` ON `test_testlink`.`testlink_addres` = `test_address`.`address_id`
WHERE `user_id` = 5
Please read the reference
You are using wrong syntax. You should mention which tables to join first then based on which fields.
SELECT * (lets say I would define the fields) FROM `test_testable`
INNER JOIN test_testlink
ON `test_testtable`.`testtable_id` = `test_testlink`.`testlink_link`
INNER JOIN `test_address`
ON `test_testlink`.`testlink_addres` = `test_address`.`address_id`
AND `test_testtable`.`user_id` = 5
select * from testlink JOIN testtable ON testlink.tableid = testtable.ID
JOIN testaddress ON testlink.addressid = testaddress.ID
WHERE testtable.ID = 5

Mysql Join Won't Select

I have been doing a lots of research online and from my understanding i think my query is ok
That is why i need your help to point me out what im doing wrong.
What My Query Should Do
My query should fetch our stock level from both warehouse
Problem Is
if the product is not in both warehouse the query dont give any result.
Ok so first i have two database of warehouse stock level. that look like that.
Databases
-warehouse1
-warehouse2
Table
-product
Columns
-id
-SKU
-qty
So my Query is
SELECT
warehouse1.product.id as 1_id,
warehouse2.product.id as 2_id ,
warehouse1.product.SKU,
warehouse1.product.qty as 1_qty,
warehouse2.product.qty as 2_qty
FROM `warehouse1`.`product`
LEFT JOIN `warehouse2`.`product`
ON
(`warehouse1`.`product`.`SKU` = `warehouse2`.`product`.`SKU`)
WHERE
warehouse1.product.SKU = '$sku'
OR
warehouse2.product.SKU = '$sku'
ORDER BY
(1_qty + 2_qty) DESC
if i make the where clause like this
WHERE warehouse1.product.SKU = '$sku'
it is then working but i can't get stock from both warehouse.
What should i do if i want to receive the stock level from both warehouse even if there is no product that im asking for in this database.
Thanks
Try a FULL OUTER JOIN. You're using a LEFT JOIN. That requires that the DB fetch all records that match your WHERE clause on the LEFT side of the join, which is warehouse1, and any potentially matching records from warehouse2 (the right side of the join). If a SKU exists only in warehouse2, you don't see it.
Switching to a FULL OUTER JOIN forces the DB to fetch all matching records from BOTH sides of the join, regardless of which side(s) the matching records exist on.
you can also do this with a union
(SELECT
warehouse1.product.id as 1_id,
warehouse1.product.SKU,
warehouse1.product.qty as 1_qty
FROM `warehouse1`.`product`
WHERE
warehouse1.product.SKU = '$sku' )
union
(SELECT
warehouse2.product.id as 2_id ,
warehouse2.product.SKU,
warehouse2.product.qty as 2_qty
FROM `warehouse2`.`product`
WHERE warehouse2.product.SKU = '$sku' )
Combine your OR's in () (... OR ...):
SELECT
warehouse1.product.id as 1_id,
warehouse2.product.id as 2_id ,
warehouse1.product.SKU,
warehouse1.product.qty as 1_qty,
warehouse2.product.qty as 2_qty
FROM `warehouse1`.`product`
LEFT JOIN `warehouse2`.`product`
ON
(`warehouse1`.`product`.`SKU` = `warehouse2`.`product`.`SKU`)
WHERE (warehouse1.product.SKU = '$sku'
OR
warehouse2.product.SKU = '$sku')
ORDER BY
(1_qty + 2_qty) DESC

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