select salary from employees order by salary desc
MINUS
select salary from employees where rownum<10 order by salary desc;
I am unable to use order by with MINUS ,it says sql command not properly ended.
Please suggest!
Given what the business question seems to be (show the salaries of employees where the salary is not in the top ten of salaries) I would think analytics would be a choice worth considering:
select salary
from (select salary,
rank() over (order by salary) as salary_rank
from employees
)
where salary_rank > 10
order by salary;
Using analytics would also only scan EMPLOYEES once, whereas the original query would scan it twice.
Related
I'm in a bit of a bind - I want to make a stored procedure that displays the number of each item sold and orders them from most to least. The relevant data comes from two different tables:
ITEMS | itemid | itemname
SALES | itemdid
I can display the itemid and count of each item sold with this query:
SELECT * FROM (
SELECT ITEMID,
COUNT (ITEMID) AS COUNTOF
FROM SALES GROUP BY ITEMID
ORDER BY COUNTOF DESC);
I can display the itemname of each item sold with this one:
SELECT ITEMS.ITEMNAME
FROM ITEMS
JOIN SALES
ON SALES.ITEMID = ITEMS.ITEMID;
However, I can not seem to get the itemname to display next to the count of the item sold. I'm really struggling with this. Thanks
What you are looking for is a JOIN or INNER JOIN.
SELECT s.ITEMID,i.ITEMNAME, COUNT (s.ITEMID) AS COUNTOF FROM SALES AS s
INNER JOIN ITEMS AS i ON i.itemid=s.itemid
GROUP BY s.ITEMID,i.ITEMNAME
ORDER BY COUNTOF DESC
I'm trying to join two databases on the ID. The first database on price quotes does not have the data on websites, so I want to join it in from the logs database. However, in the logs database the ID is not unique, but the first chronological appearance of the ID - this is the right website.
When I run the query below, I get:
Resources exceeded during query execution.
Hence I don't know whether the problem is the code or something else.
Thanks
SELECT ID, user,busWeek, count(*) as num FROM [datastore.quotes]
Join (
select objectID, first(website) from (
select objectID, website, date from [datastore.allLogs]
order by date) group by objectID)
as Logs
on ID = objectID
group by ID,user,busWeek
Can you try:
SELECT ID, user,busWeek, count(*) as num FROM [datastore.quotes]
Join EACH (
select objectID, first(website) from (
select objectID, website, date from [datastore.allLogs]
order by date) group EACH by objectID)
as Logs
on ID = objectID
group by ID,user,busWeek
Note the 'EACH' - that keyword won't be needed in the future, but it's still useful today.
I think the issue is in ORDER BY. This brings all calculation to one node which causes "Resources Exceeded" message. I understand you need it to bring first (by date) website for each object.
Try to rewrite this select (inside join) to be partitioned.
For example using window functions with OVER(PARTITION BY ... ORDER BY)
In this case, I think, you have chance to make this in parallel
See below for reference
Window Functions
I have two tables in hive:
Table1: uid,txid,amt,vendor Table2: uid,txid
Now I need to join the tables on txid which basically confirms a transaction is finally recorded. There will be some transactions which will be present only in Table1 and not in Table2.
I need to find out number of avg of transaction matches found per user(uid) per vendor. Then I need to find the avg of these averages by adding all the averages and divide them by the number of unique users per vendor.
Let's say I have the data:
Table1:
u1,120,44,vend1
u1,199,33,vend1
u1,100,23,vend1
u1,101,24,vend1
u2,200,34,vend1
u2,202,32,vend2
Table2:
u1,100
u1,101
u2,200
u2,202
Example For vendor vend1:
u1-> Avg transaction find rate = 2(matches found in both Tables,Table1 and Table2)/4(total occurrence in Table1) =0.5
u2 -> Avg transaction find rate = 1/1 = 1
Avg of avgs = 0.5+1(sum of avgs)/2(total unique users) = 0.75
Required output:
vend1,0.75
vend2,1
I can't seem to find count of both matches and occurrence in just Table1 in one hive query per user per vendor. I have reached to this query and can't find how to change it further.
SELECT A.vendor,A.uid,count(*) as totalmatchesperuser FROM Table1 A JOIN Table2 B ON A.uid = B.uid AND B.txid =A.txid group by vendor,A.uid
Any help would be great.
I think you are running into trouble with your JOIN. When you JOIN by txid and uid, you are losing the total number of uid's per group. If I were you I would assign a column of 1's to table2 and name the column something like success or transaction and do a LEFT OUTER JOIN. Then in your new table you will have a column with the number 1 in it if there was a completed transaction and NULL otherwise. You can then do a case statement to convert these NULLs to 0
Query:
select vendor
,(SUM(avg_uid) / COUNT(uid)) as avg_of_avgs
from (
select vendor
,uid
,AVG(complete) as avg_uid
from (
select uid
,txid
,amt
,vendor
,case when success is null then 0
else success
end as complete
from (
select A.*
,B.success
from table1 as A
LEFT OUTER JOIN table2 as B
ON B.txid = A.txid
) x
) y
group by vendor, uid
) z
group by vendor
Output:
vend1 0.75
vend2 1.0
B.success in line 17 is the column of 1's that I put int table2 before the JOIN. If you are curious about case statements in Hive you can find them here
Amazing and precise answer by GoBrewers14!! Thank you so much. I was looking at it from a wrong perspective.
I made little changes in the query to get things finally done.
I didn't need to add a "success" colummn to table2. I checked B.txid in the above query instead of B.success. B.txid will be null in case a match is not found and be some value if a match is found. That checks the success & failure conditions itself without adding a new column. And then I set NULL as 0 and !NULL as 1 in the part above it. Also I changed some variable names as hive was finding it ambiguous.
The final query looks like :
select vendr
,(SUM(avg_uid) / COUNT(usrid)) as avg_of_avgs
from (
select vendr
,usrid
,AVG(complete) as avg_uid
from (
select usrid
,txnid
,amnt
,vendr
,case when success is null then 0
else 1
end as complete
from (
select A.uid as usrid,A.vendor as vendr,A.amt as amnt,A.txid as txnid
,B.txid as success
from Table1 as A
LEFT OUTER JOIN Table2 as B
ON B.txid = A.txid
) x
) y
group by vendr, usrid
) z
group by vendr;
I have the following situation (simplified):
2 BiTemp Tables
basicdata (id, btmp_tsd, name, prename)
extendeddata (id, btmp_tsd, basicid, codename, codevalue)
In extendeddata, there can be multible entries for one basicdata with each a different codename and value.
I have to create an SQL to select all rows which have changed since a specified time. For the basicdata table this is relatively simple:
SELECT ID, BTMP_TSD, NAME, PRENAME
FROM BASICDATA BD
WHERE BTMP_TSD =
(SELECT MAX(BTMP_TSD)
FROM BASICDATA BD2
WHERE BD2.ID = BD.PRTNR_ID
AND BD2.BTMP_TSD > :MINTSD
AND BD2.BTMP_TSD <= :MAXTSD
)
ORDER BY ID
WITH UR
Now I will need to Join on the second table to get the codevalue for the codename 'test'. The problem is, it may not exist, in this case, the row should be collected anyway. But if there is a row but not within the timerange, I should not get a result.
I hope I was able to explain my issue. Joins are one of the things I still don't see trough...
Edit:
Okay here's a sample
basicdata:
id,btmp_tsd,name,prename
1,2013-05-25,test,user
2,2013-06-26,user,two
3,2013-06-26,peter,hans
1,2013-06-20,test,us3r
2,2013-10-30,us3r,two
extendeddata:
id,btmp_tsd,basicid,codename,codevalue
1,2013-05-25,1,superadmin,1
2,2013-06-26,3,admin,1
3,2013-11-25,1,superadmin,0
Okay now having these entries and I want all userid's which have had any changes since 2013-10-01 I should get
User1 (Because the extendeddata superadmin had a change)
User2 (Had a Name change and I want him even tough he has no entry on the extendeddata table)
not User3 (He has an entries on both tables but it's not in the specified range)
The following query should do what you want.
select *
from basicdata b left outer join extendeddata e on b.id=e.basicid
where b.btmp_tsd >= '2013-10-01'
or e.btmp_tsd >= '2013-10-01'
DISCLAIMER: I didn't test the sql. So syntax might not be 100% perfect.
I have 3 table customer (customerid,name), customerbooking(bookingid,customerid), transact(transacted,bookingid,typeoftransaction)
I want to fetch the name of the ‘customer name’ who has the maximum typeoftransact=’current’. Customer table is linked to customerbooking via customerid, and customerbooking is linked to transact via bookingid. Using join I am able to get the individual records, but unable to get the Max value
Please try this to meet your scenerio
SELECT
C.Name
, Count(BookingID)
FROM Customer C
INNER JOIN customerbooking CB ON CB.CustomerID = C.customerId
INNER JOIN transact T ON T.bookingid = CB.BookingId
WHERE T.Typeoftransaction='current'
GROUP BY C.Name
Hope this helps