How to join 5 tables with IF conditions - mysql

I want to join 5 tables through book_id. I tried:
SELECT booked_room_info . * , booking_info . * , hotel_info.name as
hotelname,hotel_info.address as hoteladdress,hotel_info.contact as
hotelcontact , personal_info . *,room_registration.room_name as
roomname,room_registration.price as roomprice,room_registration.price as
roomprice,room_registration.description as
roomdescription,room_registration.image as roomimage
FROM booked_room_info
JOIN booking_info ON booking_info.booking_id = booked_room_info.booking_id
JOIN hotel_info ON hotel_info.id = booking_info.hotel_id
JOIN personal_info ON personal_info.booking_id = booked_room_info.booking_id
JOIN room_registration ON room_registration.hotel_id = booking_info.hotel_id
WHERE booked_room_info.booking_id= 1
But if i have 2 booking on booking_id = 1 but it fetched 10 result. I think I should make a if condition like. If (booked.room_type && book_info.hotel_id) is same then only fetch rows from room_registration but how can I aacomplish it.
booked_room_info
------
id | booking_id | room_type | check_in | check_out
1 | 1 | delux | 2015/1/2 | 2015/1/5
booking_info
---------
id | booking_id | hotel_id | user_id
1 | 1 | 2 | 1
hotel_info
----------
id | name | address | user_id
2 |palm hotel | newyork | 1
personal_info
-------------
id |full_name | address | nationality | booking_id
1 | sushil stha | new york | smth | 1
room_registration
-----------------
id | room_name | price | image | hotel_id | user_id
1 | delux | 1000 |room.jpg | 2 | 1

There is an error in your last join:
JOIN room_registration ON room_registration.hotel_id = booking_info.hotel_id
You are joining these tables using hotel_id column. There are probably 5 rows in room_registration table with hotel_id=2. So after joining you receive 2*5=10 rows instead of expected 2.
So you should join with this table in different way.
If you want to join every row with exacly one row from room_registration table then you have to specify more precise join condition.
To join room_registration table properly you may add room_registration_id column to booking_info table. Then you can join using:
JOIN room_registration ON room_registration.id = booking_info.room_registration_id

Use INNER JOIN's, removed the duplicate field.
SELECT
bri.*,
bi.*,
hi.name AS hotelname, hi.address as hoteladdress, hi.contact AS hotelcontact,
pi.*,
rr.room_name AS roomname, rr.price AS roomprice, rr.description AS roomdescription, rr.image AS roomimage
FROM booked_room_info bri
INNER JOIN booking_info bi ON bri.booking_id = bi.booking_id
INNER JOIN hotel_info hi ON bi.hotel_id = hi.id
INNER JOIN personal_info pi ON bri.booking_id = pi.booking_id
INNER JOIN room_registration rr ON bi.hotel_id = rr.hotel_id
WHERE bri.booking_id = 1

Related

How to count in mysql

I have this query in mySQL where I would like to sum the line product of each doctor but I dont know how to do it.
use avant_medical;
select
sales.doctor_id as DoctorID,
line_products.id as LineProductID,
line_products.name as LineProductName
from `doctors`
inner join `sales` on `doctors`.`id` = `sales`.`doctor_id`
inner join `inventories` on `sales`.`id` = `inventories`.`sale_id`
inner join `products` on `inventories`.`product_id` = `products`.`id`
inner join `line_products` on `products`.`lineProduct_id` = `line_products`.`id`
order by `doctors`.`id` asc;
lPID= lineProductID
|DrID|lPID |
| -- | ----|
| 1 | 7 |
| 1 | 6 |
| 1 | 6 |
| 1 | 7 |
| 1 | 7 |
| 1 | 7 |
| 1 | 6 |
This is how I want:
Doctor 1
lineID | quantity
7 | 4
6 | 3
I try this query only in mySQL
The keyword you are looking for is count, not sum. Summing would add up every lineProductID as if they where regular mathematical values, while counting will add up how many times a given lineProductID is found.
select
sales.doctor_id as DoctorID,
line_products.id as LineProductID,
line_products.name as LineProductName,
-- We count the number of occurrences of each line_product.id
COUNT(line_products.id) as LineProductQty
from `doctors`
inner join `sales` on `doctors`.`id` = `sales`.`doctor_id`
inner join `inventories` on `sales`.`id` = `inventories`.`sale_id`
inner join `products` on `inventories`.`product_id` = `products`.`id`
inner join `line_products` on `products`.`lineProduct_id` = `line_products`.`id`
-- Never forget to properly GROUP your aggregate functions, such as COUNT() or SUM()!
GROUP BY sales.doctor_id, line_products.id, line_products.name
order by `doctors`.`id` asc;
Since you didn't provided full schema to test this, I made a small, very artificial demo, but should be representative of how the query above works.

How to exclude rows when a certain condition is met in MySQL

I have two datatables. One table contains information of participants (Participants). And a table which contains all registrations for the event (Registrars).
+----+-------+
| id | name |
+----+-------+
| 1 | Peter |
+----+-------+
| 2 | John |
+----+-------+
+-----------+----------+
| person_id | event_id |
+-----------+----------+
| 1 | 1 |
+-----------+----------+
| 2 | 2 |
+-----------+----------+
| 2 | 1 |
+-----------+----------+
I run a MySQL query to get the information of registrars of an event. The query looks like this:
SELECT name
FROM Participants
INNER JOIN Registrars
ON Participants.id=Registrars.person_id
WHERE
event_id = 1
Now I want to build a query where if the participant also registered for event 2 it will not be returned in the result of the query the reg. How can I achieve this in one query?
You can group by participant and use conditional aggregation in the HAVING clause to set the conditions:
SELECT p.id, p.name
FROM Participants p INNER JOIN Registrars r
ON p.id = r.person_id
WHERE r.event_id IN (1, 2)
GROUP BY p.id, p.name
HAVING MAX(r.event_id = 1) = 1
AND MAX(r.event_id = 2) = 0
You can extend the code by adding more conditions in a similar way.
SELECT name
FROM Participants as p
INNER JOIN Registrars as reg
ON P.id=Reg.person_id
WHERE
reg.event_id = 1
and not exists (select 1 from Registrars as strr where strr.event_id=2 and p.id=strr.person_id )

MySQL Summing & Counting Child Values in Another Table

BOOKINGS TABLE
id | price | anotherVal
-----------------------------
1 | 10000 | *
2 | 20000 | *
3 | 1000 | *
4 | 8000 | *
BOOKING PAYMENTS TABLE
id | bookingId | amount | currencyId | mxnAmount
--------------------------------------------------
1 | 1 | 100.00 | 1 | 100.00
2 | 1 | 300.00 | 3 | 6400.00
3 | 2 | 500.21 | 1 | 500.21
4 | 4 | 123.95 | 6 |
4 | 4 | 800.00 | 1 | 800.00
I need to get all BOOKINGS_TABLE columns and then for each booking add up the mxnAmount column, but also the result should tell if all rows in BOOKING_PAYMENTS_TABLE had an mxnAmount so i can know if the mxnAmount is final or there's some rows left to be updated, i have a query that works for the first part:
SELECT b.*, SUM(p.mxnAmount) FROM bookings b LEFT JOIN bookingPayments p ON b.id = p.bookingId GROUP BY b.id
I figured i could make us of COUNT() to count all rows in BOOKING_PAYMENTS_TABLE but then how can i get the number for the rows that have an mxnAMOUNT?
SELECT b.*, SUM(p.mxnAmount), COUNT(p.id) FROM bookings b LEFT JOIN bookingPayments p ON b.id = p.bookingId GROUP BY b.id
I tried this:
SELECT b.*, SUM(p.mxnAmount), COUNT(p.id), COUNT(pp.id) FROM bookings b LEFT JOIN bookingPayments p ON b.id = p.bookingId LEFT JOIN bookingPayments pp ON b.id = pp.bookingId WHERE pp.mxnAmount IS NOT NULL GROUP BY b.id
But then the query returns only bookings that have all their payments rows with an mxnAmount, any leads?
I figured i could make us of COUNT() to count all rows in BOOKING_PAYMENTS_TABLE but then how can i get the number for the rows that have an mxnAMOUNT?
Just COUNT() that particular column: this gives you the number of non-null values in the column for each group:
SELECT b.*, SUM(p.mxnAmount), COUNT(p.id), COUNT(p.mxnAmount)
FROM bookings b
LEFT JOIN bookingPayments p ON b.id = p.bookingId
GROUP BY b.id
If you want to know if any mxmamount in the group is missing, you can do:
MAX(p.id IS NOT NULL AND p.mxnAmount IS NULL) has_missing_mxnAmount

IF using inner join MySql?

How do I build a joint to select either table
Table jobs
Id | name | salary | company | type
1 | php | 17.850 | 5 | 1
2 | mysql | 4.500 | 89 | 2
2 | nodejs | 7.500 | 89 | 1
Table Company
Id | name | Area | status
1 | Facebook| Developer| 1
2 | Google | Manager | 1
Table Candidate
Id | name | City | phone
1 | Alan Kout | Nevada | 1 555 6666
2 | Wagner Mom | L.A. | 1 444 8965
My query mysql, inner join candidate or company
If type == 1 in table jobs INNER JOIN ON table company
If type == 2 in table jobs INNER JOIN ON table candidate
Example
SELECT * FROM table_jobs
IF(table_jobs.type == 1, INNER JOIN table_company, INNER JOIN table_candidate)
This is possible?
You can achieve this using a LEFT JOIN instead of an INNER JOIN:
SELECT *
FROM table_jobs tj
LEFT JOIN table_company tco ON tj.type = 1 AND tco.id = tj.id
LEFT JOIN table_candidate tca ON tj.type = 2 AND tca.id = tj.id
This will join to table_company where the type is 1, and table_candidate where the type is 2.
You can then SELECT whichever columns are needed from each table as appropriate.
Use left join and coalesce():
SELECT tj.*,
coalesce(co.name, ca.name) as name,
. . .
FROM table_jobs tj LEFT JOIN
table_company co
ON co.id = tj.id and tj.type = 1 LEFT JOIN
table_candidate ca
ON ca.id = tj.id and tj.type = 2;
If you want both joins in one result you can use the UNION operator
SELECT *
FROM table_jobs INNER JOIN table_company
WHERE table_jobs.type=1
UNION
SELECT *
FROM table_jobs INNER JOIN table_candidate
WHERE table_jobs.type=2

Mysql select rows with same id's (3 tables)

I have the following tables:
'blog_content'
'blog_media'
'blog_media_content'
| blog_id | media_id |
========================
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 3 | 4 |
I want to select all blog_media.uri's where blog_media.media_id equals blog_media_content.blog_id.
Please help me to achieve my aim.
An inner join between blog_media and blog_media_content tables would suffice.
SELECT
bm.uri
FROM blog_media bm
INNER JOIN blog_media_content bmc ON bm.media_id = bmc.media_id
WHERE bmc.blog_id =3;
Note:
If you need any additional information from blog table then you need an additional inner join like below:
...INNER JOIN blog_table b ON bmc.blog_id = b.blog_id...
EDIT:
In order to get records for all blog_ids :
SELECT
bm.uri
FROM blog_media bm
INNER JOIN blog_media_content bmc ON bm.media_id = bmc.media_id
ORDER BY bmc.blog_id;