EXISTS in filter returning too many values - tsql

I need to write a query that uses EXISTS, rather than IN, so that it will run fast. The filter is being fed so many parameter values that EXISTS seems like the only option. The difference is between a 20+ minute query and a 5 second query.
This is the query I have:
SELECT DISTINCT d.GROUP_NAME
FROM [EMPLOYEE] e JOIN [DATA_FACT] d ON (e.KEY = d.KEY)
WHERE d.DATE BETWEEN #Start and #End
AND EXISTS
(
select '1234567' -- #ID
)
AND e.Location IN (#Location)
ORDER BY d.GROUP_NAME ASC
The problem is that it is returning too many records. Based on the values I'm passing to filter on, I should get 1 row back but instead I am getting 28.
If I remove the EXISTS and add the following then I get the 1 record I need:
AND e.ID IN ('1234567')
Is there a way to fix the query to work with EXISTS so that I get the correct results?

This is essentially what you want if you are going to try to use exists to filter your data_fact table by parameters in your employee table. Not sure how much it's going to improve your performance though when you throw a massive number of employee IDs at it.
SELECT
d.GROUP_NAME
FROM [DATA_FACT] AS d
WHERE d.DATE BETWEEN #Start and #End
AND EXISTS
(
select 1
from EMPLOYEE AS e
WHERE d.[KEY] = e.[KEY]
AND e.[Location] IN (#Location)
AND e.ID IN ('1234567')
)
ORDER BY d.GROUP_NAME ASC

Related

Use postgresql query results to form another query

I am trying to select from one table using the select result from another table. I can run this in two queries but would like to optimize it into just one.
First query.. Select ids where matching other id
select id from lookuptable where paid = '547'
This results in something like this
6316352
6316353
6318409
6318410
6320468
6320469
6320470
6322526
6322527
6324586
6324587
6326648
I would like to then use this result to make another selection. I can do it manually like below. Note, there could be many rows with these values so I've been using a IN statement
select * from "othertable" where id in (6316352,6316353,6318409,6318410,6320468,6320469,6320470,6322526,6322527,6324586,6324587,6326648);
select
ot.*
from
"othertable" as ot
join
lookuptable as lt
on
ot.id = lt.id
where
lt.paid = '547'
The IN operator supports not just value lists but also subqueries, so you can literally write
select * from "othertable" where id in (select id from lookuptable where paid = '547');

Update a column with row_number with duplicate records without PK

I have a table with duplicate records but without primary key. Data looks like this:
I want to update one empty column with one of column concatenate with row_number. After update, I want to achieve this:
Since the table does not have a unique column, which means I would join back to a CTE or subquery. I know in sql server, it can be done like this:
UPDATE X
SET X.NEW_KEY = X.PERSONNUMBER + '-' + X.NEW_CODE_DEST
FROM (
SELECT ROW_NUMBER() OVER (PARTITION BY PERSONNUMBER) AS NEW_CODE_DEST,PERSONNUMBER,NEW_KEY
FROM EMPLOYEE
) as X;
I tried same logic in postgresql but it didn't work. It threw an error:
SQL Error [42P01]: ERROR: relation "x" does not exist
I also tried this in
UPDATE EMPLOYEE
SET NEW_KEY = X.PERSONNUMBER || '-' || X.NEW_CODE_DEST
FROM (
SELECT ROW_NUMBER() OVER (PARTITION BY PERSONNUMBER) AS NEW_CODE_DEST,PERSONNUMBER
FROM EMPLOYEE
) as X;
The NEW_KEY is updated with duplicate value, not surprise there.
So is there a equivalent method in to achieve the same update result? Or I have my query wrong?
Really appreciate the help!

oracle: grouping on merged columns

I have a 2 tables FIRST
id,rl_no,adm_date,fees
1,123456,14-11-10,100
2,987654,10-11-12,30
3,4343,14-11-17,20
and SECOND
id,rollno,fare,type
1,123456,20,bs
5,634452,1000,bs
3,123456,900,bs
4,123456,700,bs
My requirement is twofold,
1, i first need to get all columns from both tables with common rl_no. So i used:
SELECT a.ID,a.rl_no,a.adm_date,a.fees,b.rollno,b.fare,b.type FROM FIRST a
INNER JOIN
SECOND b ON a.rl_no = b.rollno
The output is like this:
id,rl_no,adm_date,fees,rollno,fare,type
1,123456,14-11-10,100,123456,20,bs
1,123456,10-11-12,100,123456,900,bs
1,123456,14-11-17,100,123456,700,bs
2,Next i wanted to get the sum(fare) of those rollno that were common between the 2 tables and also whose fare >= fees from FIRST table group by rollno and id.
My query is:
SELECT x.ID,x.rl_no,,x.adm_date,x.fees,x.rollno,x.type,sum(x.fare) as "fare" from (SELECT a.ID,a.rl_no,a.adm_date,a.fees,b.rollno,b.fare,b.type FROM FIRST a
INNER JOIN
SECOND b ON a.rl_no = b.rollno) x, FIRST y
WHERE x.rollno = y.rl_no AND x.fare >= y.fees AND x.type IS NOT NULL GROUP BY x.rollno,x.ID ;
But this is throwing in exceptions.
ORA-00979: not a GROUP BY expression
00979. 00000 - "not a GROUP BY expression"
The expected output will be like this:
id,rollno,adm_date,fare,type
1,123456,14-11-10,1620,bs
So could someone care to show an oracle newbie what i'm doing wrong here?
It looks like there's a couple different problems here;
Firstly, you're trying to group by an x.ID column which doesn't exist; it looks like you'll want to add ID to the selected columns in your sub-query.
Secondly, when aggregating with GROUP BY, all selected columns need to be either listed in the GROUP BY statement or aggregated. If you're grouping by rollno and ID, what do you want to have happen to all the extra values for adm_date, fees, and type? Are those always going to be the same for each distinct rollno and ID pair?
If so, simply add them to the GROUP BY statement, ie,
GROUP BY adm_date, fees, type, rollno, ID
If not, you'll need to work out exactly how you want to select which one to be output; If you've got output like your example (adding in an ID column here)
ID,adm_date,fees,rollno,fare,type
1,14-11-10,100,123456,20,bs
1,10-11-12,100,123456,900,bs
1,14-11-17,100,123456,700,bs
Call that result set 'a'. If I run;
SELECT a.ID, a.rollno, SUM(a.fare) as total_fare
FROM a
GROUP BY a.ID, a.rollno
Then the result will be a single row;
ID,rollno,total_fare
1,123456,1620
So, if you also select the adm_date, fees, and type columns, oracle has no idea what you mean to do with them. You're not using them for grouping, and you're not telling oracle how you want to pick which one to use.
You could do something like
SELECT a.ID,
FIRST(a.adm_date) as first_adm_date,
FIRST(a.fees) as first_fees,
a.rollno,
SUM(a.fare) as total_fare,
FIRST(a.type) as first_type
FROM a
GROUP BY a.ID, a.rollno
Which would give the result;
ID,first_adm_date,first_fees,rollno,total_fare,first_type
1,14-11-10,100,123456,1620,bs
I'm not sure if that's what you mean to do though.

Specifice order to tables in postgres

I just created a temporary table as:
create temporary table userAndProductSales as
select p.p_name, u.u_name, u.s_price, u.quantity
from product p
join userAndStates u
on p.s_id = u.s_id
Now I want to select some columns with a particular order. For example, I want the select to give me an output of:
u_name1 p_name1
u_name1 p_name2
u_name1 p_name3
u_name1 p_name4
...
u_name2 p_name1
u_name2 p_name2
u_name2 p_name3
....
and so on and so forth. How do I get this ouput? I've tried something on the lines of:
select (select u_name from userandproductsales order by u_name), p_name from userandproductsales
but I'm getting an error
UPDATE: Figured out that the table I'm joining isn't giving me the correct data I want. Thanks for the help though.
Here is how to use ORDER BY :
SELECT * from userandstatesales
order by u_name , p_name
Unless there is a reason for creating a temporary table (like needing to access it later in the same session), you should avoid the expense and simply do a order by from your select. For example:
select p.p_name, u.u_name, u.s_price, u.quantity
from product p
join userAndStates u
on p.s_id = u.s_id
order by u.u_name, p.p_name;

PostgreSQL - select the results of two subqueries

I have 2 complex queries that are both subqueries in postgres, the results of which are:
q1_results = id , delta , metric_1
q2_results = id , delta , metric_2
i'd like to combine the results of the queries, so the outer query can access either:
results_a = id , delta , metric_1 , metric_2
results_b = id , delta , combined_metric
i can't figure out how to do this. online searches keep leading me to UNION , but that keeps the metrics in the same column. i need to keep them split.
It's not entirely clear what you're asking in the question and the comments, but it sounds like you might be looking for a full join with a bunch of coalesce statements, e.g.:
-- create view at your option, e.g.:
-- create view combined_query as
select coalesce(a.id, b.id) as id,
coalesce(a.delta, b.delta) as delta,
a.metric1 as metric1,
b.metric2 as metric2,
coalesce(a.metric1,0) + coalesce(b.metric2,0) as combined
from (...) as results_a a
full join (...) as results_b b on a.id = b.id -- and a.delta = b.delta maybe?