I have two tables:
booking - records the order detail
id | booking_amount
-------------------
1 | 150
2 | 500
3 | 400
payment - records the payment for order
id | booking_id | amount
------------------------
1 | 1 | 100
2 | 1 | 50
2 | 2 | 100
I want to find all bookings where the payments are not complete. With the above data, we expect the answer to be 2,3, because the sum of payments for booking_id=1 matches the corresponding booking_amount in the booking_table.
To answer your question, you have 2 things you need to think about :
you want the total amount in your table payment by every booking row
you want to join your booking_amount table with payment.
Part 1 is quite simple:
SELECT sum(amount) as TotalP, booking_id FROM payment GROUP BY booking_id
Just a basic query with a simple aggregate function...
For part 2, we want to join booking_amount and payment; the basic JOIN would be:
SELECT * FROM booking b
LEFT JOIN payment p ON b.id = p.booking_id
We do a LEFT JOIN because we may have some booking who are not in the payment table. For those bookings, you will get NULL value. We will use a COALESCE to replace the NULL values by 0.
The final query is this:
SELECT b.id, COALESCE(TotalP, 0), b.booking_amount
FROM
booking b
LEFT JOIN
(SELECT sum(amount) as TotalP, booking_id FROM payment GROUP BY booking_id) as T
ON b.id = T.booking_id
WHERE COALESCE(TotalP, 0) < b.booking_amount
You need to use a outer join to combine your two tables and look for your conditions. Also, you will need to use SUM(..) function to get the sum of the amount for each id in the payment table.
Please try this:
select b.id from booking b
left outer join -- cant be inner join because we lose id:3 in that case.
(
select booking_id, SUM(amount) as Total
from payment group by booking_id
) p on b.id = p.booking_id
where b.booking_amount > Coalesce(Total,0) --Coalesce is required for such values coming NULL, like id:3, they will be assigned as 0.
Related
I have two tables like this
rooms
id | number
1 | 111
2 | 112
occupied_rooms
id | check_in | check_out | room_id
1 | 2017-10-01 | 2017-10-04 | 1
I want to get all the unoccupied rooms according to date check_in and check_out for this I tried
select r.id
, r.number
from rooms r
left join occupied_rooms o
on r.id = o.room_id
where (o.check_in not between "2017-10-05" and "2017-10-08" )
or (o.check_in >= "2017-10-05" and o.check_out <= "2017-10-08"))
but this query giving me result like this. which is incorrect.
id | number
1 | 111
What is wrong with this query?
Thank you for your any help and suggestions
Just join the two tables on the condition that the id matches and the range of intended stay overlaps with the range in the occupied_rooms table.
SELECT r.*
FROM rooms r
LEFT JOIN occupied_rooms t
ON r.id = t.id AND
('2017-10-02' <= t.check_out AND '2017-10-03' >= t.check_in)
WHERE
t.id IS NULL; -- NULL value indicates the room did not overlap
-- with any existing reservations
You can also check out this great reference question on how to deal with overlapping ranges in SQL queries. It makes the problem you are facing much simpler.
Demo
Your data in table occupied_rooms meets the first condition in "where";
check_in date(2017-10-01) is not between "2017-10-05" and "2017-10-08" and your where is or.
Thus, the result is included this data.
Can you tell us what output you expect?
I am making queries to extract data from database which holds customer order. There's one table which holds customer id's and the customer's name. Another table which has the order id, customer id of who placed the order, a quantity of the item bought, and an item id. The last table holds the item id's and item names. I am trying to sort these to show an individual's most popular purchase, but am having issues properly grouping and ordering to produce the correct result, below is an example of what is intended.
customers
1 | John
---+-----
2 | Jane
orders
1 | 2 | 4 | 1
---+---+---+---
2 | 2 | 5 | 2
---+---+---+---
3 | 2 | 2 | 1
---+---+---+---
4 | 1 | 1 | 2
items
1 | Chair
---+-------
2 | Sofa
After properly sorting and grouping, the output table should like:
John | Sofa
------+------
Jane | Chair
Currently I can connect the item names to the purchaser and return a random item bought, but not the most popular by quantity. I have tried entering multiple fields into group by and managed to properly group the items by name and sort by quantity, but in doing so the customer id's became ungrouped. Been trying to solve this for days so any help would be appreciated. Please note that this is a very simplified version of the actual problem where many more tables are involved, including multiple items table which are being joined together to one.
You should use group by on joined tables
select
b.name
, c.name
, sum(quantity) as tot
from orders as a
inner join Customers as b on a.customer_id = b.id
inner join Items as c on a.item_id = c.id
group by b.name, c.name
order by tot
Selecting the sum of the quantities per customer-item group is easy, but selecting the top seller is a bit harder.
The first step is the query to get all the groups with the sums of the quantities for each customer-item:
SELECT
customer_name,item_name,SUM(quantity)
FROM
orders o
JOIN customers c ON o.customer_id=c.id
JOIN items i ON o.item_id=i.id
GROUP BY customer_name,item_name;
Then to only select the groups with the maximum quantity sums we use some trickery:
SELECT
customer_name,item_name,SUM(quantity),
(SELECT SUM(quantity) AS qmax
FROM
orders o2
JOIN customers c2 ON o2.customer_id=c2.id
JOIN items i2 ON o2.item_id=i2.id
WHERE c2.id=c.id
GROUP BY c2.customer_name,i2.item_name
ORDER BY qmax DESC LIMIT 1) AS qmax
FROM
orders o
JOIN customers c ON o.customer_id=c.id
JOIN items i ON o.item_id=i.id
GROUP BY customer_name,item_name
HAVING SUM(quantity)=qmax;
Edit:
Here's a link to a fiddle: SQLFiddle
Suppose I have these two tables:
|Customers | |Purchases |
---------------- -----------------
|CusID |----- |PurchaseID |
|CusName | |---<|CusID |
|CusAge | |ItemName |
|CusDateAdded | |DatePurchased |
I am needing to filter my result set by multiple ItemNames. Say I want to return all Customers who are between the ages of 18 and 24 who purchased a 'camera' AND a 'phone'. I can run the following query to obtain all records for customers between the age range:
SELECT CusID
FROM Customers AS C
JOIN Purchases AS P
ON C.CusID = P.CusID
WHERE C.CusAge BETWEEN 18 AND 24
However when it comes time to filter on the ItemName column in Purchases table how does one filter on multiple rows? Supposing it is possible without multiple queries?
SELECT C.CusID
FROM Customers AS C
JOIN Purchases AS P ON C.CusID = P.CusID
WHERE C.CusAge BETWEEN 18 AND 24
AND ItemName IN ('camera','phone')
GROUP BY C.CusID
HAVING count(distinct ItemName) = 2
Group by the customer and return only those having both items.
I believe this will answer your question: SQL FIDDLE
SELECT C.CustID,C.CustName,P.ItemName
FROM Customers AS C
JOIN Purchases AS P ON C.CustID = P.CustID
GROUP BY C.CustID,C.CustName,P.ItemName
HAVING P.ItemName IN ('camera','phone')
I have the following tables in a succession of 1-to-many relationships:
company_company, company_portfolio, building_site and statistics_meter. The area of difficulty I am having is the final table, statistics_meter.
For the benefit of this exercise, it's structure is as follows:
Records are related within the same table, with some being parent meters, and some being child meters. Where a record is a child, it will have parent_meter_id set, and building_id, which crucially, is how the table is LEFT JOIN'ed set to NULL.
id | parent_meter_id | site_ref | building_id
1 | NULL | some building | 45
2 | NULL | some other building | 45
3 | 1 | and another | NULL
4 | 1 | one another one | NULL
5 | 2 | final one | NULL
I have two requirements:
1 - count the number of parent meters where the building_id is set (which I am doing successfully)
2 - count the number of meters where the parent_meter_id matches the meter_id of those counted in (1)
Thus I would expect a result whereby (1) = 2 and (2) = 3.
Here is the SQL I've got so far...I tried fiddling around with a SUM case when but I think it's totally wrong. Is this even possible within one query?
Thanks for the help.
SELECT
building_site.id as site_id,
building_site.site_ref as building_name,
COUNT(statistics_meter.id) AS meter_count,
SUM(CASE WHEN statistics_meter.parent_meter_id = [???] THEN 1 ELSE 0 END) AS check_meter_count
FROM company_company
LEFT JOIN company_portfolio ON company_portfolio.company_id=company_company.id
LEFT JOIN building_site ON building_site.portfolio_id=company_portfolio.id
LEFT JOIN statistics_meter ON statistics_meter.building_id=building_site.id
WHERE company_company.id=41
GROUP BY building_site.id
Well if I understand you, you'll need to use a subquery to get the parent meters with a building id, and then join that to your main table.
SQL Fiddle
select
sm.id,
sm.parent_meter_id,
sm2.id as ID2,
sm.site_ref,
sm.building_id
from
statistics_meter sm
inner join (
select
id,
parent_meter_id
from
statistics_meter
where
building_id is not null) sm2
on sm.parent_meter_id = sm2.id
Not sure if this is the most efficient way to do it, but in the end I performed a left join and subquery as below and performed two counts, one COUNT() for total number to answer my requirement (2) and a COUNT(distinct) to answer my requirement (1)
SELECT
count(distinct statistics_meter.id) as meter_count,
count(statistics_meter.id) as check_meter_count
FROM company_company
LEFT JOIN company_portfolio ON company_portfolio.company_id=company_company.id
LEFT JOIN building_site ON building_site.portfolio_id=company_portfolio.id
LEFT JOIN statistics_meter ON statistics_meter.building_id=building_site.id
LEFT JOIN (select * from statistics_meter where parent_meter_id is not NULL) sm2 on sm2.parent_meter_id = statistics_meter.id
I need a Full Outer Join in mysql. I found a solution here: Full Outer Join in MySQL My problem is that t1 and t2 are subqueries themselves. So resulting query looks like a monster.
What to do in this situation? Should I use views instead of subqueries?
Edit:
I'll try to explain a bit more. I have orders and payments. One payment can cower multiple orders, and one order can be cowered by multiple payments. That is why I have tables orders, payments, and paymentitems. Each order has field company (which made this order) and manager (which accepted this order). Now I need to group orders and payments by company and manager and count money. So I want to get something like this:
company1 | managerA | 200 | 200 | 0
company1 | managerB | Null | 100 | 100
company1 | managerC | 300 | Null | -300
company2 | managerA | 150 | Null | -150
company2 | managerB | 100 | 350 | 250
The query, I managed to create:
SELECT coalesce(o.o_company, p.o_company)
, coalesce(o.o_manager, p.o_manager)
, o.orderstotal
, p.paymentstotal
, (coalesce(p.paymentstotal, 0) - coalesce(o.orderstotal, 0)) AS balance
FROM
(((/*Subquery A*/SELECT orders.o_company
, orders.o_manager
, sum(o_money) AS orderstotal
FROM
orders
WHERE
(o_date >= #startdate)
AND (o_date <= #enddate)
GROUP BY
o_company
, o_manager) AS o
LEFT JOIN (/*Subquery B*/SELECT orders.o_company
, orders.o_manager
, sum(paymentitems.p_money) AS paymentstotal
FROM
((payments
INNER JOIN paymentitems
ON payments.p_id = paymentitems.p_id)
INNER JOIN orders
ON paymentitems.p_oid = orders.o_id)
WHERE
(payments.p_date >= #startdate)
AND (payments.p_date <= #enddate)
GROUP BY
orders.o_company
, orders.o_manager) AS p
ON (o.o_company = p.o_company) and (o.o_manager = p.o_manager))
union
(/*Subquery A*/
right join /*Subquery B*/
ON (o.o_company = p.o_company) and (o.o_manager = p.o_manager)))
This is simplified version of my query. Real query is much more complex, that is why I want to keep it as simple as it can be. Maybe even split in to views, or may be there are other options I am not aware of.
I think the clue is in "group orders and payments by company". Break the outer join into a query on orders and another query on payments, then add up the type of money (orders or payments) for each company.
If you are trying to do a full outer join and the relationship is 1-1, then you can accomplish the same thing with a union and aggreagation.
Here is an example, pulling one column from two different tables:
select id, max(col1) as col1, max(col2) as col2
from ((select t1.id, t1.col1, NULL as col2
from t1
) union all
(select t23.id, NULL as col1, t2.col2
from t2
)
) t
group by id