Given a simple case like this:
Gender DeptID
--------------
M 1
F 1
M 2
F 2
F 2
What SQL statement I need to write If I want to generate the following result using SQL without using advanced CUBE, Rollup, etc., just using plain SQL-92:
GenderSum Dept1Sum Dept2Sum
----------------------------
M 1 1
F 1 2
I was wondering how such information would be generated by ETL in the past using SQL?
Remark: It is possible to use Group by on gender and union that with a group by on DetptId to get a vertical result set but this is clearly not what I want.
You can try the following pivot query:
SELECT Gender AS GenderSum,
SUM(CASE WHEN DeptID = 1 THEN 1 ELSE 0 END) AS Dept1Sum,
SUM(CASE WHEN DeptID = 2 THEN 1 ELSE 0 END) AS Dept2Sum
FROM yourTable
GROUP BY Gender
Related
I am a newbie studying MSSQL and Database.
I am trying to write a SQL query to count values in the column.
Following table is original one.
name value
----------
A 1
A 1
A 2
B 1
B 2
I want to get a table like this.
name one two
--------------
A 2 1
B 1 1
A has two 1 and one 2 and B has one 1 and 2. It seems I can accomplish it using COUNT built-in function. I tried but failed. Is there any idea to do it?
use conditional aggregation
select name, sum(case when value=1 then 1 else 0 end) as one,
sum(case when value=2 then 1 else 0 end) as two
from table_name group by name
enter image description hereI am trying to write an SQL query to get below output.
table has below data:
ID GENDER
10 M
10 F
10 F
20 F
20 M
Output:
ID Male Female
10 1 2
20 1 1
do i need to use case with group by. Can someone help here.
use simple group
select id,sum(case when GENDER = 'M' then 1 else 0 end) as Male,
sum(case when GENDER = 'F' then 1 else 0 end) as FeMale
from tablename
group by id
I am using the Adventureworks sample database (HumanResources.Employee table is the database).
For simplicity I will take a sample of the table:
HireDate Gender SalariedFlag
-----------------------------------------
2014-01-01 M 1
2015-01-30 F 1
2014-01-30 M 1
2014-02-12 F 0
2014-03-11 F 1 and so on
Code:
SELECT
YEAR(hiredate), F, M
FROM
HumanResources.employee
PIVOT
(sum(SalariedFlag)
FOR gender IN ([F], [M])
) AS gg
-- Unable to use sum though since its bit field
Expected output:
Year F M
-------------------
2014 1 2 # count(SalariedFlag)
2015 1 0 # count(SalariedFlag)
But I really get:
No name F M
-------------------------------
2014 0 1
2015 1 0
2014 0 1
2014 1 0
2014 1 0
and so on.
So basically in output its not considering the salariedflag column at all, it is simply returning 1 in F if the person was female and 1 in M if person was male.
What am I doing wrong?
Firstly, counting the value of SalariedFlag isn't going to achieve anything. COUNT counts the number of rows with a non-NULL value, and all your rows have a non-NULL value. Instead you want to COUNT the number of rows where the value of SalariedFlag is 1.
You might, therefore, be able to SUM the column, however, as it's a "flag" it's more likely to be a bit and you can't SUM a bit. Therefore using COUNT and checking the value is 1 with a CASE would likely be better.
Personally, rather than using the restrictive PIVOT operator, I would suggest you use conditional aggregation. This gives you the following:
SELECT YEAR(HireDate) AS HireYear,
COUNT(CASE WHEN Gender = 'M' AND SalariedFlag = 1 THEN 1 END) AS M,
COUNT(CASE WHEN Gender = 'F' AND SalariedFlag = 1 THEN 1 END) AS F
FROM #YourTable
GROUP BY YEAR(HireDate);
db<>fiddle
I am working with some course data in a Presto database. The data in the table looks like:
student_id period score completed
1 2016_Q1 3 Y
1 2016_Q3 4 Y
3 2017_Q1 4 Y
4 2018_Q1 2 N
I would like to format the data so that it looks like:
student_id 2018_Q1_score 2018_Q1_completed 2017_Q3_score
1 0 N 5
3 4 Y 4
4 2 N 2
I know that I could do this by joining to the table for each time period, but I wanted to ask here to see if any gurus had a recommendation for a more scalable solution (e.g. perhaps not having to manually create a new join for each period). Any suggestions?
You can just use conditional aggregation:
select student_id,
max(case when period = '2018_Q1' then score else 0 end) as score_2018q1,
max(case when period = '2018_Q1' then completed then 'N' end) as completed_2018q1,
max(case when period = '2017_Q3' then score else 0 end) as score_2017q3
from t
group by student_id
I have two tables
nameTB contains:
id | name | gender | nationalityid
nationalityTB contains:
nationalityid | nationalityname
I want create sql query to return the result:
nationalityname female male total
UK 10 5 15
USA 11 7 18
You should be able to easily get the result by joining the tables and using an aggregate function with conditional logic (like a CASE expression):
select nt.nationalityname,
sum(case when nm.gender = 'Female' then 1 else 0 end) Female,
sum(case when nm.gender = 'Male' then 1 else 0 end) Male,
count(*) Total
from nationalityTB nt
left join nameTB nm
on nt.nationalityid = nm.nationalityid
group by nt.nationalityname;
See SQL Fiddle with Demo