Sorry if this is a stupid question, but why does sql show Total trips in the table below? I tried it with other data set (london_bicycles) and it didn't have this issue.
Here is the code:
SELECT
end_station_name
,Count (*) as trips
FROM `bigquery-public-data.new_york_citibike.citibike_trips`
GROUP BY(end_station_name)
ORDER BY trips DESC
LIMIT 10
Result of the query
Related
I have a huge amount stock data. We are tracking every day stock level amount. My purpose is to get query which take records only when the amount is change:
Sample:
Desired result:
Try this query with subquery:
Select date_id, product,warehouse,amount
From
(
Select
date_id, product, warehouse, amount,
lag(amount) over (partition by product, warehouse order by date_id) amount_prev
From TABLENAME
) x
Where amount <> amount_prev
It's an exercise that is not solved in the book in which I am studying.
The goal is to find the seller who has had the highest number of sales per month,
during all the months for which there is registered information. The problem is that I do not know how to divide tuples into periods of one month.
First table is:
Table Sellers
Id_seller
Name_Product
And the other one is:
Table Product
Name_Product
View_datetime
Budget
What did i do?
I made this query:
SELECT id_seller FROM(SELECT id_seller, COUNT(id_seller)
FROM SELLERS INNER JOIN PRODUCT
ON SELLERS.name_product = PRODUCT.name_product
GROUP BY id_seller HAVING COUNT(id_seller)>= 1
ORDER BY 2 DESC)
WHERE ROWNUM = 1;
The query returns me the seller that most sales has done, but not "per month since there are records" as the statement asks. Any ideas? I'm so lost...
The idea is to compare the total sales of each salesman in this month (sysdate), with those of a month ago, two months ago ... so long as there are older records. And get the maximum from each seller. And then you print the seller with more sales from the previous list. If a seller sells 400 products this month(April, the sysdate), but another seller sold in October last year 500, the result would be the second seller . That's what I do not know how to do.
Thanks ^^
You could try this query
select MonthName, id_seller, max(TotalSales) from (
select to_char(sysdate, 'Month') MonthName, sellers.id_seller, count(sellers.id_seller) TotalSales
from sellers inner join product
on sellers.name_product = product.name_product
group by to_char(view_datetime, 'Month'), sellers.id_seller
) tab
group by MonthName, id_seller
There are a few points to make...
The tables are weird. I assume your table sellers would better be called sales, right?
In this example, having count... >= 1 is a no-op. Count could only be 0 if there were no rows at all, in which case there would be no row in the group- by output. You can just leave this count away, here.
To get the sales per month, just add the month to the group by. I.e. group by id_seller, To_date(view_datetime,'YYYYMM').
I Have a query to get bill data, grouped by the calendar year and the week of the year. I want to have the evolution of bills in total. So not only the number of bills of 1 week but from the beginning until the week. I have following query
SELECT DD.CAL_YEAR, DD.WEEK_OF_YEAR AS "Date by week", SUM(DISTINCT FAB.ID) OVER ( ORDER BY DD.CAL_YEAR, DD.WEEK_OF_YEAR ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW ) AS "Number of bills"
FROM BILLS_TABLE FAB
JOIN DIM_DATE DD ON FAB.BALANCE_DATE_ID = DD.ID
GROUP BY DD.CAL_YEAR,DD.WEEK_OF_YEAR;
But when I execute this query I get following exception:
Error: ORA-30487: ORDER BY not allowed here
SQLState: 99999 ErrorCode: 30487
The order by clause is needed for the OVER function, so what is wrong?
The problem is really the use of distinct inside sum.
Because you have the order by clause, that means you are doing a cumulative sum. Performing a distinct in that case doesn't really make any sense. That's what the error is actually trying to tell you.
The documentation for the SUM analytic function mentions this:
If you specify DISTINCT, then you can specify only the query_partition_clause of the analytic_clause. The order_by_clause and windowing_clause are not allowed.
My Query is
SELECT unnest(array [repgroupname,repgroupname||'-'
||masteritemname,repgroupname||'-' ||masteritemname||'-'||itemname]) AS grp
,unnest(array [repgroupname,masteritemname,itemname]) AS disp
,groupname1
,groupname2
,groupname3
,sum(qty) AS qty
,sum(freeqty) AS freeqty
,sum(altqty) AS altqty
,sum(discount) AS discount
,sum(amount) AS amount
,sum(stockvalue) AS stockvalue
,sum(itemprofit) AS itemprofit
FROM (
SELECT repgroupname
,masteritemname
,itemname
,groupname1
,groupname2
,groupname3
,units
,unit1
,unit2
,altunits
,altunit1
,altunit2
,sum(s2.totalqty) AS qty
,sum(s2.totalfreeqty) AS freeqty
,sum(s2.totalaltqty) AS altqty
,sum(s2.totaltradis + s2.totaladnldis) AS discount
,sum(amount) AS amount
,sum(itemstockvalue) AS stockvalue
,sum(itemprofit1) AS itemprofit
FROM sales1 s1
INNER JOIN sales2 s2 ON s1.txno = s2.txno
INNER JOIN items i ON i.itemno = s2.itemno
GROUP BY repgroupname
,masteritemname
,itemname
,groupname1
,groupname2
,groupname3
,units
,unit1
,unit2
,altunits
,altunit1
,altunit2
ORDER BY itemname
) AS tt
GROUP BY grp
,disp
,groupname1
,groupname2
,groupname3
Here
Sales1 table have 144513 Records
Sales2 Table have 438915 Records
items Table have 78512 Records
This Query take 6 seconds to produce result.
How to Optimize this query?
am using postgresql 9.3
That is a truly horrible query.
You should start by losing the ORDER BY in the sub-select - the ordering is discarded by the outer query.
Beyond that, ask yourself why you need to look to see a summary of every songle row in th DBMS - does this serve any useful purpose (if the query is returning more than 20 rows, then the answer is no).
You might be able to make it go faster by ensuring that the foreign keys in the tables are indexed (indexes are THE most important bit of information to look at whenever you're talking about performance and you've told us nothing about them).
Maintaining the query as a regular snapshot will mitigate the performance impact.
I use SET ROWCOUNT 27900 And then select two columns:
Select
emp.employeeid,
empd.employeedetailid
From
employee emp (NOLOCK)
join
employeedetail empd (NOLOCK) on emp.employeeid = empd.employeeid
This query executes in 3 sec
If I use SET ROWCOUNT 27950 then the same query takes 20 sec to execute.
I am not a sql DBA, why there is a difference of 17 sec for just 50 rows. Is this anything related to page size or index?
Can anyone help me to fine tune the query?
Have you tried doing this using TOP instead of SET ROWCOUNT, and adding an ORDER BY?
SELECT TOP 27900 emp.employeeid, ...
ORDER BY ...;
This will give the optimizer a much better chance at optimizing. In simplest terms, SET ROWCOUNT is applied after the entire query has been processed, and only affects the rows that are sent back to the caller...