conditional aggregation on two different groups in SQL - sql

Here is my data
COUNTYID POLLUTANT TYPE EMISSION
1 A 1
1 A 2
1 B 1
1 B 2
2 A 1
2 A 2
2 B 1
2 B 2
3 A 1
3 A 2
3 B 1
3 B 2
if I do
SELECT sum(EMISSION) from table where POLLUTANT = 'A' group by COUNTYID;
I would get pollution from Polutant 'A'. how can I write a query to get following data:
column 1 with sum of A, column 2 with sum of B, column 3 with sum of A and B?
Thank you

You can use case for filter the value you need
select COUNTYID, sum(case when POLLUTANT='A'then EMISSION else 0 END) tot_a
, sum(case when POLLUTANT='B'then EMISSION else 0 END) tot_b
, sum(EMISSION) tot_a_b
from my_table
group by COUNTYID

You can use conditional aggregation. This moves the filtering conditions from the where clause to the sum()s:
select countyid,
sum(case when emission = 'A' then emission else 0 end) as A,
sum(case when emission = 'B' then emission else 0 end) as B,
sum(emission) as total
from t
group by countyid;

I would like to give some idea. We can use pivot table for answer your question
SELECT * from dbo.[Table_1]
PIVOT
(Sum([type_emmssion]) for [polutant] in ([A], [B]) ) as PivotTable
group by [CountryId] ;

you have to use case statemet:
SELECT
SUM( CASE WHEN POLLUTANT = 'A' THEN EMISSION ELSE 0 END) AS A_EMISSION
SUM( CASE WHEN POLLUTANT = 'B' THEN EMISSION ELSE 0 END) AS B_EMISSION
SUM(EMISSION) AS total_emission
FROM table
GROUP BY COUNTYID;

Related

Adding a dummy identifier to data that varies by position and value

I am working on a project in SQL Server with diagnosis codes and a patient can have up to 4 codes but not necessarily more than 1 and a patient cannot repeat a code more than once. However, codes can occur in any order. My goal is to be able to count how many times a Diagnosis code appears in total, as well as how often it appears in a set position.
My data currently resembles the following:
PtKey
Order #
Order Date
Diagnosis1
Diagnosis2
Diagnosis3
Diagnosis 4
345
1527
7/12/20
J44.9
R26.2
NULL
NULL
367
1679
7/12/20
R26.2
H27.2
G47.34
NULL
325
1700
7/12/20
G47.34
NULL
NULL
NULL
327
1710
7/12/20
I26.2
J44.9
G47.34
NULL
I would think the best approach would be to create a dummy column here that would match up the diagnosis by position. For example, Diagnosis 1 with A, and Diagnosis 2 with B, etc.
My current plan is to rollup the diagnosis using an unpivot:
UNPIVOT ( Diag for ColumnALL IN (Diagnosis1, Diagnosis2, Diagnosis3, Diagnosis4)) as unpvt
However, this still doesn’t provide a way to count the diagnoses by position on a sales order.
I want it to look like this:
Diagnosis
Total Count
Diag1 Count
Diag2 Count
Diag3 Count
Diag4 Count
J44.9
2
1
1
0
0
R26.2
1
1
0
0
0
H27.2
1
0
1
0
0
I26.2
1
1
0
0
0
G47.34
3
1
0
2
0
You can unpivot using apply and aggregate:
select v.diagnosis, count(*) as cnt,
sum(case when pos = 1 then 1 else 0 end) as pos_1,
sum(case when pos = 2 then 1 else 0 end) as pos_2,
sum(case when pos = 3 then 1 else 0 end) as pos_3,
sum(case when pos = 4 then 1 else 0 end) as pos_4
from data d cross apply
(values (diagnosis1, 1),
(diagnosis2, 2),
(diagnosis3, 3),
(diagnosis4, 4)
) v(diagnosis, pos)
where diagnosis is not null;
Another way is to use UNPIVOT to transform the columns into groupable entities:
SELECT Diagnosis, [Total Count] = COUNT(*),
[Diag1 Count] = SUM(CASE WHEN DiagGroup = N'Diagnosis1' THEN 1 ELSE 0 END),
[Diag2 Count] = SUM(CASE WHEN DiagGroup = N'Diagnosis2' THEN 1 ELSE 0 END),
[Diag3 Count] = SUM(CASE WHEN DiagGroup = N'Diagnosis3' THEN 1 ELSE 0 END),
[Diag4 Count] = SUM(CASE WHEN DiagGroup = N'Diagnosis4' THEN 1 ELSE 0 END)
FROM
(
SELECT * FROM #x UNPIVOT (Diagnosis FOR DiagGroup IN
([Diagnosis1],[Diagnosis2],[Diagnosis3],[Diagnosis4])) up
) AS x GROUP BY Diagnosis;
Example db<>fiddle
You can also manually unpivot via UNION before doing the conditional aggregation:
SELECT Diagnosis, COUNT(*) As Total Count
, SUM(CASE WHEN Position = 1 THEN 1 ELSE 0 END) As [Diag1 Count]
, SUM(CASE WHEN Position = 2 THEN 1 ELSE 0 END) As [Diag2 Count]
, SUM(CASE WHEN Position = 3 THEN 1 ELSE 0 END) As [Diag3 Count]
, SUM(CASE WHEN Position = 4 THEN 1 ELSE 0 END) As [Diag4 Count]
FROM
(
SELECT PtKey, Diagnosis1 As Diagnosis, 1 As Position
FROM [MyTable]
UNION ALL
SELECT PtKey, Diagnosis2 As Diagnosis, 2 As Position
FROM [MyTable]
WHERE Diagnosis2 IS NOT NULL
UNION ALL
SELECT PtKey, Diagnosis3 As Diagnosis, 3 As Position
FROM [MyTable]
WHERE Diagnosis3 IS NOT NULL
UNION ALL
SELECT PtKey, Diagnosis4 As Diagnosis, 4 As Position
FROM [MyTable]
WHERE Diagnosis4 IS NOT NULL
) d
GROUP BY Diagnosis
Borrowing Aaron's fiddle, to avoid needing to rebuild the schema from scratch, and we get this:
https://dbfiddle.uk/?rdbms=sqlserver_2019&fiddle=d1f7f525e175f0f066dd1749c49cc46d

Creating a view from two tables, with case and sum on one table

I'm having some troubles trying to create a view from two tables, which includes a sum + case for the first table. I've tried multiple different joins/unions, and I can get just the XTS table to come over, or just the case count scenarios to work, but I cannot get both.
here are the tables. For Table 1, UWI is non-unique. For Table 2, UWI is Unique. new_view is what I'm hoping to achieve for my view.
TABLE 1
UWI ET
1 A
1 B
1 B
2 B
2 C
2 C
TABLE 2
UWI XTS
1 10
2 20
3 10
4 30
new_view
UWI XTS B_COUNT C_COUNT
1 10 4 3
2 20 3 4
3 10 4 5
4 30 3 2
Here's what I'm currently working with.
CREATE VIEW new_view AS
SELECT t1.UWI,
sum(case when t1.ET='B' then 1 else 0 end) as B_COUNT,
sum(case when t1.ET='C' then 1 else 0 end) as C_COUNT,
sum(case when t1.ET='D' then 1 else 0 end) as D_COUNT,
sum(case when t1.ET='E' then 1 else 0 end) as E_COUNT,
sum(case when t1.ET='F' then 1 else 0 end) as F_COUNT
FROM TABLE_1 t1
INNER JOIN (SELECT t2.UWI, t2.XTS AS TSC
from TABLE_2 t2)
on t1.UWI = t2.UWI
group by t1.UWI;
Your sample select does not match your sample data, so this is a guess but I think you just need to move the aggregation into an apply()
select t2.UWI, t2.XTS, s.*
from Table_2 t2
outer apply (
select
sum(case when t1.ET='B' then 1 else 0 end) as B_COUNT,
sum(case when t1.ET='C' then 1 else 0 end) as C_COUNT,
sum(case when t1.ET='D' then 1 else 0 end) as D_COUNT,
sum(case when t1.ET='E' then 1 else 0 end) as E_COUNT,
sum(case when t1.ET='F' then 1 else 0 end) as F_COUNT
from table_1 t1
where t1.UWI = t2.UWI
group by t1.UWI
)s

Counting values within the same row in SQL Server

My SQL Server problem is as follows: let's say we have clients and we wish to rate them based on 4 categories (Score_1...Score_4) on a scale of 0 to 2. I have a table presented below:
What I want my code to do is count the number of 0, 1, and 2 values each of my clients recieved. The result table I would like to get would like this:
So client_1 got two 0 scores, one 1 score and one 2 score, client_2 got one 0 score, one 1 score and two 2 scores. Any suggestions? Thanks in advance!
You can unpivot, then do conditional aggregation:
select t.id,
sum(case when x.score = 0 then 1 else 0 end) cnt_0,
sum(case when x.score = 1 then 1 else 0 end) cnt_1,
sum(case when x.score = 2 then 1 else 0 end) cnt_2
from mytable t
cross apply (values (score_1), (score_2), (score_3), (score_4)) x(score)
group by t.id

Best way to do a Count in TSQL

I am not so good in TSQL and i want to write a report in this manner:
input: Table A
ID Company Product Flag
1 A Car Y
2 A Van N
3 B Van Y
4 A Part N
Output
Company Y N
A 1 2
B 1 0
if one can assist in TSQL...
You could use conditional aggregation:
SELECT Company
,SUM(CASE WHEN Flag = 'Y' THEN 1 ELSE 0 END) AS Y
,SUM(CASE WHEN Flag = 'N' THEN 1 ELSE 0 END) AS N
FROM tab
GROUP BY Company
You are looking for conditional aggregation:
select company,
sum(case when flag = 'Y' then 1 else 0 end) as num_y,
sum(case when flag = 'N' then 1 else 0 end) as num_n
from t
group by company;
You can use CASE expressions (the people call it "conditional aggregation") to count the flagged products per customer like this (which will ignore a record when the Product column is empty):
SELECT Company
, COUNT(CASE Flag WHEN 'Y' THEN Product END) AS Y
, COUNT(CASE Flag WHEN 'N' THEN Product END) AS N
FROM YourTable
GROUP BY Company;
Or you can use this PIVOT query, which is a short form of writing the above:
SELECT Company, Y, N
FROM (SELECT Company, Product, Flag FROM YourTable) AS src
PIVOT (COUNT(Product) FOR Flag IN (Y, N)) AS pvt;
use case when
select company,
sum(case when flag='Y' then 1 else 0 end) as Y,
sum(case when flag='N' then 1 else 0 end) as N from tabe_data
group by company

Query to find the intersection of three different classes

Trying to get the count of distinct people in the intersection of top two circles. (In the figure I am trying to get the count for the region labeled as d). Keys 1,2 and 3 belong to first circle and 4,5,6 belong to second circle and 7,8,9,10 belong to third circle.
Table structure is as follows:
customer key
A234 1
A345 4
A12 5
A989 6
This is the query I have tried:
select count(distinct(c.key))
from (select c.key
from tab1 c
group by c.key
having sum(case when key1 in (1,2,3) then 1 else 0 end) > 0 and
sum(case when key1 in (4,5,6,7,8) then 1 else 0 end) = 0
) c
I think you simply got your HAVING clause mixed up.
select count(*)
from
(
select key
from tab1
group by key
having sum(case when key1 in (1,2,3) then 1 else 0 end) > 0 -- in circle A
and sum(case when key1 in (4,5,6) then 1 else 0 end) > 0 -- in circle B
and sum(case when key1 in (7,8,9,10) then 1 else 0 end) = 0 -- not in circle C
) region_d;