Show two different sum columns based on another column.
For this table:
ID Item Quantity Location
1 1 10 A
2 1 10 B
3 1 10 A
4 2 10 A
5 2 10 A
6 2 10 B
7 3 10 A
8 3 20 A
I need to see the total quantities for both location A and location B (to compare which is higher), but only for items that have a location B:
Expected result:
Item Quantity A Quantity B
1 20 10
2 20 10
I've been trying this but getting errors:
SELECT st.item, st.qty ALIAS(stqty),
(SELECT SUM(dc.qty)
FROM table dc
WHERE st.item = dc.item) ALIAS(dcqty))
FROM table st
WHERE location ='b'
I can do this easily with two queries obviously, but I was hoping for a way to do it in one.
you can use a sum with case statement to do your pivot then a having to exclude rows with no total for b
here is the fiddle
https://www.db-fiddle.com/f/rS8fgvWoFxn879Utc2CKbu/0
select Item,
sum(case when Location = 'A' then Quantity else 0 end),
sum(case when Location = 'B' then Quantity else 0 end)
from myTable
group by Item
having sum(case when Location = 'B' then Quantity else 0 end) > 0
Related
I have a table which has the following columns:
user_id - includes duplicates
product_id - includes duplicates
purchases - number of purchases of given product_id
My table looks somewhat like this:
user_id date product_id purchases
0 1 1 1 4
1 1 2 1 0
2 1 3 2 0
3 1 4 2 0
4 2 1 1 1
5 2 2 1 0
6 2 3 1 1
7 3 1 2 0
8 3 2 3 0
9 4 1 5 1
My goal is to calculate the following metric:
% of products that were purchased at least once, grouped by user
For example: user 1 had 2 products, one of them got purchased at least once, the other one did not get purchased at all. So the metric would be the number of products that got purchased at least once / number of all products per user: 1/2 * 100 = 50%
I have little SQL experience so I do not have any legitimate code that could be corrected.
My desired output would be like this:
user_id total_products products_with_purchases metric
0 1 2 1 50%
1 2 1 1 100%
2 3 2 0 0%
3 4 1 1 100%
I would appreciate seeing a good practice solution to this problem. Many thanks!
select
user_id,
count(distinct product_id) as total_products,
count(distinct case when purchases > 0 then product_id end) as products_with_purchases,
100.00 * count(distinct case when purchases > 0 then product_id end)
/ count(distinct product_id) as metric
from T as t
group by user_id
https://rextester.com/EDSY39439
You can do this all in one query but this is the type of situation where it is easier to understand with sub-queries -- sql optimizer should make it fast.
select
user_id,
total_products,
products_with_purchase,
(products_with_purchase / total_products) * 100 as metric
from (
select -- group by user to get totals
user_id,
count(product_id) as total_products,
sum(case when purchases > 0 then 1 else 0 end) as products_with_purchase
from ( -- group by user and product and get purchase items
SELECT user_id, product_id, sum(purchases) as purchases
FROM table
GROUP BY user_id, product_id
) X
group by user_id
) X2
I Am Mohit Sahni
you can solve the above problem with the below SQL Code:
select
user_id,
count(distinct product_id) as total_products,
sum(case when purchases = 0 then 0 else 1 end) as products_with_purchases,
((sum(case when purchases = 0 then 0 else 1 end))/count(distinct product_id))*100 as metric
from
table
group by
user_id
I am confused about this both from front end point of view as well as querying the data from SQLite Database. If you have any idea how to solve either of these please do answer.
SQLite Database
I have a table likes this:
transactionId | productId | quantity
1 2 1
2 4 0
3 1 null
4 3 1
5 9 1
6 6 0
7 1 1
8 7 1
9 8 1
10 2 1
11 0 null
12 3 1
13 5 1
14 7 1
15 1 0
16 2 1
17 9 1
18 0 null
19 2 1
Now I want to display this data in groups of 5 units(i.e. groups till 5 units are completed) in list in my flutter app.
So 1st group will have 8 items,
2nd will have 6 items,
and 3rd group will have 5 items
(and is still incomplete since more items can be added till quantity for that group becomes 5)
Something like this:
Now my App can have multiple groups like this. Also, I don't think Grid view builder can work here since for each group I'll have to display some data for the group as well as accumulated data (which isn't shown in the picture)
Questions:
1) How to query data from SQFLite database?
2) How to display the queried data in my Flutter App front end?
Unfortunately, this type of problem requires a recursive CTE (or other iterative processing).
Assuming that transactionId is consecutive with no gaps:
with recursive cte as (
select transactionId, productId,
coalesce(quantity, 0) as quantity,
1 as bin
from t
where transactionId = 1
union all
select t.transactionId, t.productId,
(case when cte.quantity > 5
then 0 else cte.quantity
end) + coalesce(t.quantity, 0) as quantity,
(case when cte.quantity > 5 then 1 else 0 end) + cte.bin as bin
from cte join
t
on t.transactionId = cte.transactionId + 1
)
select *
from cte;
If transactionId has gaps or other issues, just use row_number() (in another CTE) to create an appropriate column for the where clauses.
I have the following table :
user category number
1 A 8
1 B 6
2 A 1
2 C 9
3 B 5
I want to "unfold" or "dummify" the category column and fill them with the "number" column to obtain:
user cat_A cat_B cat_C
1 8 6 0
2 1 0 9
3 0 5 0
Is it possible to achieve this in SQL (Impala) ?
I found this question How to create dummy variable columns for thousands of categories in Google BigQuery?
However it seems a little bit complex and I'd rather do it in Pandas.
Is there a simpler solution, knowing that I have 10 categories (A, B, C, D etc)?
You can try to use condition aggregate function.
SELECT user,
SUM(CASE WHEN category = 'A' THEN number ELSE 0 END) cat_A,
SUM(CASE WHEN category = 'B' THEN number ELSE 0 END) cat_B,
SUM(CASE WHEN category = 'C' THEN number ELSE 0 END) cat_C
FROM T
GROUP BY user
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
I currently have a table in SQL that looks like this
PRODUCT_ID_1 PRODUCT_ID_2 SCORE
1 2 10
1 3 100
1 10 3000
2 10 10
3 35 100
3 2 1001
That is, PRODUCT_ID_1,PRODUCT_ID_2 is a primary key for this table.
What I would like to do is use this table to add in a row to tell whether or not the current row is the one that maximizes SCORE for a value of PRODUCT_ID_1.
In other words, what I would like to get is the following table:
PRODUCT_ID_1 PRODUCT_ID_2 SCORE IS_MAX_SCORE_FOR_ID_1
1 2 10 0
1 3 100 0
1 10 3000 1
2 10 10 1
3 35 100 0
3 2 1001 1
I am wondering how I can compute the IS_MAX_SCORE_FOR_ID_1 column and insert it into the table without having to create a new table.
You can try like this...
Select PRODUCT_ID_1, PRODUCT_ID_2 ,SCORE,
(Case when b.Score=
(Select Max(a.Score) from TableName a where a.PRODUCT_ID_1=b. PRODUCT_ID_1)
then 1 else 0 End) as IS_MAX_SCORE_FOR_ID_1
from TableName b
You can use a window function for this:
select product_id_1,
product_id_2,
score,
case
when score = max(score) over (partition by product_id_1) then 1
else 0
end as is_max_score_for_id_1
from the_table
order by product_id_1;
(The above is ANSI SQL and should run on any modern DBMS)