how is the best way to merge these sql queries from the db.
I'm using this but wants to add the two others into it if possible
SELECT m.username, sum(d.liter) AS TOT_LITERS, min(krl) AS TOT_KM
FROM members m JOIN
diesel d
ON (d.userid = m.id)
WHERE d.dato >= '$dx'
GROUP BY m.username
ORDER BY 2 DESC;
and the other two
SELECT SUM(liter) AS totalfuel
FROM diesel
WHERE diesel.dato >= '$dx' AND userid = ".$_COOKIE['userid']."
ORDER BY diesel.dato DESC
SELECT MIN(km) AS minikm, MAX(km) AS maxkm
FROM diesel
WHERE diesel.dato >= '$dx' AND userid = ".$_COOKIE['userid']."
ORDER BY diesel.dato DESC
They all three does what I expected them to, but I guess there has to be a better way than having three queries on the same page
Is UNION the way to go here ? I don't see how though cause they need to have the same amount of tables :P ?
EDIT: Well I don't need the user ID and that cookie thing this time. Just forgot to remove it. I'm making a highscore and would like to show the usernames, average gas, km driven, liters filled etc ..
Here's an example of a sub-query:
SELECT m.username,
(
SELECT SUM(liter) AS SumOfLiters
FROM diesel
WHERE diesel.dato >= '$dx'
AND diesel.IDField = d.IDField
) AS TotalFuel
FROM members m
JOIN diesel d ON d.userid = m.id
WHERE d.dato >= '$dx'
The sub-query (in brackets) returns a value that you can assign to a field (TotalFuel in this case).
rather than restricting everything in the where clause then trying to marry it all back you could use your top query with a few sum case whens e.g.
sum(case when userid = '.$_COOKIE['userid'].' then liter else 0 end)
Related
I am looking for a solution to the problem from Beginning Microsoft SQL Server® 2008 Programming book.(AdventureWorks database used)
Ques> Show the most recent five orders that were purchased from account numbers that have spent more than $70,000 with AdventureWorks.
I found a solution to this on See query but this is not working. What's the error in this query?
SELECT ss.AccountNumbeR, OrderDate
FROM Sales.SalesOrderHeader ss
WHERE ss.TotalDue > 70000
AND ss.AccountNumber NOT IN (SELECT TOP 5 ss.AccountNumber
FROM Sales.SalesOrderDetail so
JOIN Sales.SalesOrderHeader ss
ON SO.SalesOrderID = ss.SalesOrderID
HAVING SUM(so.LineTotal > 70000))
GROUP BY ss.TotalDue, ss.AccountNumber, OrderDate
ORDER BY OrderDate DESC
I'm not entirely sure why you though this query would work:
It's querying for orders where the account number is not in the top 5 which is the opposite of what we want, moreover TOP 5 here has no ordering so it's entirely random. And this is entirely in the wrong place, the question wants the top 5 orders, not the top 5 accounts.
It's also filtering for orders where each of the orders individually has a value greater than 70000. And HAVING SUM(so.LineTotal > 70000) is a syntax error.
I would advise you instead to use window functions here
SELECT s.AccountNumber, s.OrderDate
FROM (
SELECT so.*,
TotalPerAccount = SUM(ss.LineTotal) OVER (PARTITION BY so.AccountNumber),
rn = ROW_NUMBER() OVER (PARTITION BY so.AccountNumber ORDER BY so.OrderDate DESC)
FROM Sales.SalesOrderHeader so
JOIN Sales.SalesOrderDetail ss ON so.SalesOrderID = ss.SalesOrderID
) s
WHERE s.TotalPerAccount > 70000
AND s.rn <= 5;
db<>fiddle
I have came up with solution to count total of fields based on specific group, but it looks quite lengthy to get to the result i expect.
I have some basic knowledge when it comes to sql.
Is there obvious improvements to be made and why?
Why i would like to shorten this: Easier to implement in ORM type systems.
Changing scheme is not an option.
Schema and sample data: http://sqlfiddle.com/#!9/62df6
Query i'm using:
SELECT s.release_id,
(s.shipments_total - IFNULL(sh.shipment_entries, 0)) AS shipments_left
FROM
( SELECT release_id,
SUM(shipments) AS shipments_total
FROM subscriptions
WHERE is_paid = 1
AND shipments > 1
GROUP BY release_id ) AS s
LEFT JOIN
( SELECT release_id,
COUNT(*) AS shipment_entries
FROM shipments
GROUP BY release_id ) AS sh ON s.release_id = sh.release_id
Expected result on sample data is in sqlfiddle.
If you bring the condition in-line and remove the group by, then you don't need ifnull():
SELECT s.release_id,
(SUM(s.Shipments) -
(SELECT COUNT(*)
FROM shipments sh
WHERE sh.release_id = s.release_id
)
) AS shipments_left
FROM subscriptions s
WHERE is_paid = 1 AND shipments > 1
GROUP BY s.release_id;
The subquery returns 0 if nothing matches, not NULL (with the GROUP BY, it would return NULL). I am not sure if this is easier with your ORM model. Your original version is fine from a SQL point of view.
You can bring the join inline instead:
SELECT s.release_id,
SUM(s.Shipments) - IFNULL(( SELECT COUNT(*) AS shipment_entries
FROM shipments sh
WHERE sh.release_id = s.release_id
GROUP BY sh.release_id ), 0) AS shipments_left
FROM subscriptions s
WHERE is_paid = 1
AND shipments > 1
GROUP BY s.release_id
The execution plan for this is more performant too.
I'm trying to fetch the lowest price per day per hotel, I get multiple results.
I first try to fetch the lowest amount with the MIN() function, then inner join.
When i later try to group by outside the subquery, it just groups by the lowest id.
The SQL itself:
SELECT mt.id, mt.amount, mt.fk_hotel, mt.start_date
FROM price mt
INNER JOIN
(
SELECT price.id, MIN(price.amount) minAmount
FROM price
WHERE 1=1 AND price.start_date >= '2014-10-08' AND price.start_date <= '2014-10-10' AND price.active = 1 AND price.max_people = 2
GROUP BY id
) t
ON mt.id = t.id AND mt.amount = t.minAmount
ORDER BY mt.fk_hotel, mt.amount;
And the results looks like this:
http://jsfiddle.net/63mg3b2j/
I want to group by the start date and fk_hotel so that it groups by the lowest amount value, can anybody help me? Am I being clear?
Edit: I also need a field fk_room from the corresponding row, so i can inner join
Try this:
SELECT MIN(mt.amount) AS min_amount, mt.fk_hotel, mt.start_date
FROM price mt
WHERE
mt.active = 1 AND
mt.max_people = 2 AND
mt.start_date >= '2014-10-08' AND mt.start_date <= '2014-10-10'
GROUP BY mt.fk_hotel, mt.start_date
ORDER BY mt.fk_hotel, min_amount;
Well first of all get a table with minimum value in top row using ORDER BY and then GROUP BY for your required result
SELECT mt.id, mt.amount, mt.fk_hotel, mt.start_date
FROM
(SELECT id, amount, fk_hotel, start_date
FROM price
WHERE start_date >= '2014-10-08' AND start_date <= '2014-10-10'
AND active = 1 AND max_people = 2
ORDER BY amount DESC) AS mt
GROUP BY mt.id
Well I had to still go with a subquery, cause i needed some additional foreign key fields from the corresponding row to inner join some other stuff. It isn't a great solution, cause it fetches too much stuff, the rest is filtered out programmatically.
The most annoying thing here, when I try to use MIN() or MAX() function and get the appropriate fields to that row, it fetches the first results from the DB, which are incorrect and so i have to use a subquery to inner join to get the other fields, I can use grouping, but I had too many fields to group. Maybe I'm missing something. The amount of data doesn't grow in time, so I guess it works for me. So this is the final SQL i came up with, for future reference..
SELECT mt.*, roomtype.name roomname, hotel.name hotelname
FROM booking.price mt
INNER JOIN roomtype ON roomtype.id = mt.fk_roomtype
INNER JOIN hotel ON hotel.id = mt.fk_hotel
INNER JOIN(
SELECT price.id, MIN(price.amount) minAmount
FROM booking.price WHERE 1=1 AND price.start_date >= '2014-10-22' AND price.start_date <= '2014-10-31' AND price.max_people = 2 AND price.active = 1
GROUP BY id
) t
ON mt.id = t.id AND mt.amount = t.minAmount
ORDER BY mt.start_date, mt.amount
I'm not amazing at SQL and can't figure out how to do this. Here are the two queries I have at the moment.
SELECT TicketID_PK, SubProjectID_FK, ProjectID_FK, CustomerID_FK, TicketDate, TicketNumber,
SignOff, WorkOrder, ClientPO, TicketType, Description, Processed
FROM Tickets
INNER JOIN CustomersSubProjects ON Tickets.SubProjectID_FK = CustomersSubProjects.SubProjectID_PK
INNER JOIN CustomersProjects ON CustomersSubProjects.ProjectID_FK = CustomersProjects.ProjectID_PK
WHERE TicketID_PK = 1
SELECT ROUND(WCB+Vacation+Stat+UIC+CPP+Overhead,2) AS Total
FROM EmployeeFormula
WHERE EffectiveDate <= $TicketDate
ORDER BY EffectiveDate DESC LIMIT 1
I'm saving TicketDate as $TicketDate and using it in the second query, but I'm sure there is a way to combine the two queries to avoid this. Any help would be appreciated.
Edit: I need to select the EmployeeFormula Total (as shown in second query) by comparing the TicketDate column (in the Tickets table) to the EffectiveDate column. So the results should look like this:
TicketID_PK SubProjectID_FK ProjectID_FK CustomerID_FK TicketDate TicketNumber Total
1 1 1 1 2014-01-05 1-0501-00 30.78
Use like a subquery.
SELECT TicketID_PK, SubProjectID_FK, ProjectID_FK, CustomerID_FK, TicketDate, TicketNumber,
SignOff, WorkOrder, ClientPO, TicketType, Description, Processed, (SELECT ROUND(WCB+Vacation+Stat+UIC+CPP+Overhead,2) FROM EmployeeFormula WHERE EffectiveDate <= TicketDate ORDER BY EffectiveDate DESC LIMIT 1) AS Total
FROM Tickets
INNER JOIN CustomersSubProjects ON Tickets.SubProjectID_FK = CustomersSubProjects.SubProjectID_PK
INNER JOIN CustomersProjects ON CustomersSubProjects.ProjectID_FK = CustomersProjects.ProjectID_PK
WHERE TicketID_PK = 1
In the following query, I show the latest status of the sale (by stage, in this case the number 3). The query is based on a subquery in the status history of the sale:
SELECT v.id_sale,
IFNULL((
SELECT (CASE WHEN IFNULL( vec.description, '' ) = ''
THEN ve.name
ELSE vec.description
END)
FROM t_record veh
INNER JOIN t_state_campaign vec ON vec.id_state_campaign = veh.id_state_campaign
INNER JOIN t_state ve ON ve.id_state = vec.id_state
WHERE veh.id_sale = v.id_sale
AND vec.id_stage = 3
ORDER BY veh.id_record DESC
LIMIT 1
), 'x') sale_state_3
FROM t_sale v
INNER JOIN t_quarters sd ON v.id_quarters = sd.id_quarters
WHERE 1 =1
AND v.flag =1
AND v.id_quarters =4
AND EXISTS (
SELECT '1'
FROM t_record
WHERE id_sale = v.id_sale
LIMIT 1
)
the query delay 0.0057seg and show 1011 records.
Because I have to filter the sales by the name of the state as it would have to repeat the subquery in a where clause, I have decided to change the same query using joins. In this case, I'm using the MAX function to obtain the latest status:
SELECT
v.id_sale,
IFNULL(veh3.State3,'x') AS sale_state_3
FROM t_sale v
INNER JOIN t_quarters sd ON v.id_quarters = sd.id_quarters
LEFT JOIN (
SELECT veh.id_sale,
(CASE WHEN IFNULL(vec.description,'') = ''
THEN ve.name
ELSE vec.description END) AS State3
FROM t_record veh
INNER JOIN (
SELECT id_sale, MAX(id_record) AS max_rating
FROM(
SELECT veh.id_sale, id_record
FROM t_record veh
INNER JOIN t_state_campaign vec ON vec.id_state_campaign = veh.id_state_campaign AND vec.id_stage = 3
) m
GROUP BY id_sale
) x ON x.max_rating = veh.id_record
INNER JOIN t_state_campaign vec ON vec.id_state_campaign = veh.id_state_campaign
INNER JOIN t_state ve ON ve.id_state = vec.id_state
) veh3 ON veh3.id_sale = v.id_sale
WHERE v.flag = 1
AND v.id_quarters = 4
This query shows the same results (1011). But the problem is it takes 0.0753 sec
Reviewing the possibilities I have found the factor that makes the difference in the speed of the query:
AND EXISTS (
SELECT '1'
FROM t_record
WHERE id_sale = v.id_sale
LIMIT 1
)
If I remove this clause, both queries the same time delay... Why it works better? Is there any way to use this clause in the joins? I hope your help.
EDIT
I will show the results of EXPLAIN for each query respectively:
q1:
q2:
Interesting, so that little statement basically determines if there is a match between t_record.id_sale and t_sale.id_sale.
Why is this making your query run faster? Because Where statements applied prior to subSelects in the select statement, so if there is no record to go with the sale, then it doesn't bother processing the subSelect. Which is netting you some time. So that's why it works better.
Is it going to work in your join syntax? I don't really know without having your tables to test against but you can always just apply it to the end and find out. Add the keyword EXPLAIN to the beginning of your query and you will get a plan of execution which will help you optimize things. Probably the best way to get better results in your join syntax is to add some indexes to your tables.
But I ask you, is this even necessary? You have a query returning in <8 hundredths of a second. Unless this query is getting ran thousands of times an hour, this is not really taxing your DB at all and your time is probably better spent making improvements elsewhere in your application.