I need solution for converting SQL output
I am writing
SELECT Merchant_Master.Merchant_ID,
COUNT(Coupon_Type_ID) AS "Total Coupons",
Coupon_Type_ID,
CASE WHEN Coupon_Type_ID=1
THEN COUNT(Coupon_Type_ID)
END AS "Secret",
CASE WHEN Coupon_Type_ID=2
THEN count(Coupon_Type_ID)
END AS "Hot"
FROM Coupon_Master
INNER JOIN Merchant_Master
ON Coupon_Master.Merchant_ID=Merchant_Master.Merchant_ID
GROUP BY
Coupon_Master.Coupon_Type_ID,
Merchant_Master.Merchant_ID
and getting output as
Merchant_ID Total Coupons Coupon_Type_ID Secret Hot
----------- ------------- -------------- ----------- -----------
20 6 1 6 NULL
22 4 1 4 NULL
22 2 2 NULL 2
23 1 2 NULL 1
24 2 1 2 NULL
25 3 1 3 NULL
25 2 2 NULL 2
But I want output as
Merchant_ID Secret Hot_Coupons
----------- ------ -------------
20 6 0
22 4 2
23 0 1
24 2 0
25 3 2
Please, help me to solve the issue.
Move the CASE expressions inside the aggregates. I've also switched to using SUM rather than COUNT - there is a COUNT variant but it may display a warning about eliminating NULL values that I'd rather avoid.
SELECT Merchant_Master.Merchant_ID,
SUM(CASE WHEN Coupon_Type_ID=1
THEN 1 ELSE 0 END) AS "Secret",
SUM(CASE WHEN Coupon_Type_ID=2
THEN 1 ELSE 0 END) AS "Hot"
FROM Coupon_Master
INNER JOIN Merchant_Master
ON Coupon_Master.Merchant_ID=Merchant_Master.Merchant_ID
GROUP BY
Merchant_Master.Merchant_ID
Place it in a subquery and add group by Merchant_ID, Total, Coupons, Coupon_Type_ID
Aggregate the Secret and hot as SUM
select
...
SUM(secret) as secret,
SUM(Hot_Coupons) as Hot_Coupons
FROM (your original query) raw
group by Merchant_ID, Total, Coupons, Coupon_Type_ID
Related
I have a table that looks something like this:
id name status
2 a 1
2 a 2
2 a 3
2 a 2
2 a 1
3 b 2
3 b 1
3 b 2
3 b 1
and the resultant i want is:
id name total count count(status3) count(status2) count(status1)
2 a 5 1 2 2
3 b 4 0 2 2
please help me get this result somehow, i can just get id, name or one of them at a time, don't know how to put a clause to get this table at once.
Here's a simple solution using group by and case when.
select id
,count(*) as 'total count'
,count(case status when 3 then 1 end) as 'count(status1)'
,count(case status when 2 then 1 end) as 'count(status3)'
,count(case status when 1 then 1 end) as 'count(status2)'
from t
group by id
id
total count
count(status3)
count(status2)
count(status1)
2
5
1
2
2
3
4
0
2
2
Fiddle
Here's a way to solve it using pivot.
select *
from (select status,id, count(*) over (partition by id) as "total count" from t) tmp
pivot (count(status) for status in ([1],[2],[3])) pvt
d
total count
1
2
3
3
4
2
2
0
2
5
2
2
1
Fiddle
I have an items table
id
name
1
Nganu
2
Kae
3
Lho
Also I have an item_usages table:
id
item_id
user_id
usage_time
1
1
99
2021-10-07 00:00:00
2
2
99
2021-10-07 00:00:00
3
1
99
2021-10-08 00:00:00
4
1
22
2021-10-08 00:00:00
5
3
22
2021-10-08 00:00:00
6
1
99
2021-10-08 00:00:00
I want to find an item's total usage and user usage in a query. an example I would like to find user_id 99 usage, expected result:
id
name
total_usage
user_usage
2
Kae
1
1
1
Nganu
4
3
3
Lho
1
0
I tried:
select
"items".*,
count(total_usage.id) as total_usage,
count(user_usage.id) as user_usage
from
"items"
left join
"item_usages" as "total_usage" on "items"."id" = "total_usage"."item_id"
left join
"item_usages" as "user_usage" on "user_usage"."item_id" = "items"."id"
and "user_usage"."user_id" = 99
group by
"items"."id";
but it returns:
id
name
total_usage
user_usage
2
Kae
1
1
1
Nganu
12
12
3
Lho
1
0
item_usages only have 6 rows, why Nganu have 12 on both usage? How to fix my query?
I tried on PostgreSQL 12.8 and 13.4, I also tested on SQLFiddle(PostgreSQL 9.6), Here is the link:
http://sqlfiddle.com/#!17/f1aac/5
I got the query that returned the correct result:
select
"items".*,
min(total_usage.total_count) as total_usage,
count(user_usage.id) as user_usage
from "items"
left join
(select item_id,count(item_id) as total_count from item_usages group by item_id) as total_usage
on "items"."id" = "total_usage"."item_id"
left join "item_usages" as "user_usage"
on "user_usage"."item_id" = "items"."id" and "user_usage"."user_id" = 99
group by "items"."id";
But I don't know about the performance, so I still find faster query if possible and still wondering:
Why does my first query give wrong result?
The reason your query returns high numbers is that you join 2 times.
(From the side of Nganu) The first join will result in 4 rows, the second will map those 4 rows with 3 rows of the same table, resulting in 12 rows.
You can solve this problem with only 1 join:
select "items".id,
count(total_usage.id) as total_usage,
sum(case when total_usage.user_id = 99 then 1 else 0 end) as user_usage
from "items"
left join "item_usages" as "total_usage" on "items"."id" = "total_usage"."item_id"
group by "items".id
And it should work faster (though, on a small dataset is not visible)
I am using SQL developer and have a table called table1 which looks like this (but with loads more data):
item_id seller_id warranty postage_class
------- --------- -------- -------------
14 2 1 2
17 6 1 1
14 2 1 1
14 2 1 2
14 2 1 1
14 2 1 2
I want to identify the percentage of items sent by first class.
If anyone could help me out that would be amazing!
You can use conditional aggregation. The simplest method is probably:
select avg(case when postage_class = 1 then 1.0 else 0 end)
from t;
Note this calculates a ratio between 0 and 1. If you want a "percentage" between 0 and 100, then use 100.0 instead of 1.0.
Some databases make it possible to shorten this even further. For instance, in Postgres, you can do:
select avg( (postage_class = 1)::int )
from t;
I have a table with data as shown below (the table is built every day with current date, but I left off that field for ease of reading).
This table keeps track of people and the doors they enter on a daily basis.
Table entrance_t:
id entrance entered
------------------------
1 a 0
1 b 0
1 c 0
1 d 0
2 a 1
2 b 0
2 c 0
2 d 0
3 a 0
3 b 1
3 c 1
3 d 1
My goal is to report on people and count entrances not used(grouping on people), but ONLY if they entered(entered=1).
So using the above table, I would like the results of query to be...
id count
----------
2 3
3 1
(id=2 did not use 3 of the entrances and id=3 did not use 1)
I tried queries(some with inner joins on two instances of same table) and I can get the entrances not used, but it's always for everybody. Like this...
id count
----------
1 4
2 3
3 1
How do I not display results id=1 since they did not enter at all?
Thank you,
You could use conditional aggregation:
SELECT id, count(CASE WHEN entered = 0 THEN 1 END) AS cnt
FROM entrance_t
GROUP BY id
HAVING count(CASE WHEN entered = 1 THEN 1 END) > 0;
DBFiddle Demo
Have the following table tblTrans where
Trans_ID Trans Sequence Trans_PointsEarned Trans_PointsApplied
4452 1 1 1
4452 2 1 1
4452 3 0 1
4462 1 1 1
4462 2 1 1
4462 3 1 1
4462 4 1 1
4462 5 1 1
9101 1 0 1
9101 2 0 1
9101 3 0 1
9101 4 0 1
(useless table doesnt work)
I need to set the following on another field per every customer ID.
So Customer_OverallPoints
4452 = 2 (doesn't count 0's)
4462 = 4 (I want to cap the points to 4 based on the sequence and transID and customerID)
9101 = 0 (dont count 0's).
This needs to be applied to thousands of records based on customerID and TransID where Trans_Sequence is within the same Trans_ID and it only counts the first 4 rows that have the Trans_pointsEarned = 1.
I tried putting a psuedocode together but it just looked ridicilous and I can't even come up with the logic for this.
Thanks
Assuming that TransId is really the customer id, I think the basic logic is just an aggregation:
select t.TransId,
(case when sum(t.Trans_PointsEarned) > 4 then 4
else sum(t.Trans_PointsEarned)
end) as Customer_OverallPoints
from tblTrans t
group by t.TransId;
You can put this into an update statement as:
update customers c
set Customer_OverallPoints = (select (case when sum(t.Trans_PointsEarned) > 4 then 4
else sum(t.Trans_PointsEarned)
end)
from tblTrans t
where t.TransId = c.CustomerId
);