SQL statement for average in specific row values group columns - sql

Question

I've my table like the format below, I want to write sql statement for display column average for test1 and test2, column for main and column for position.
I've tried this sql:
select name, average as final,AVG(case when exam in('test1','test2') ) as testa
from table
where exam='main'
order by main final
group by name;
But It Does not working....help please
I want results to appear like this:

Answer 1

You could do something like the following.
Select t1.name, average12, main, rownum from (
select t1.name as name, t1.avg(average) as average12, t2.mainexam as main
from <table> t1 left join <table> t2
on t1.id = t2.id
where t2.exam = 'Main'
group by t1.name, t2.mainexam
) order by main desc;

Answer 2

Try this query for SQL Server:
SELECT
e.name AS 'Student Name'
, CAST( AVG( CASE WHEN e.Exam IN ( 'Test1', 'Test2' ) THEN e.average END ) AS FLOAT ) AS 'Test Average'
, e2.average AS 'Main Exam'
, ROW_NUMBER() OVER ( ORDER BY e2.average DESC ) AS 'Position'
FROM
exams AS e
INNER JOIN exams AS e2
ON e2.name = e.name
AND e2.exam = 'Main'
GROUP BY
e.name
, e2.average
ORDER BY
e2.average DESC
Output is:
+--------------+--------------+-----------+----------+
| Student Name | Test Average | Main Exam | Position |
+--------------+--------------+-----------+----------+
| Name1 | 60.5 | 89 | 1 |
| Name2 | 49.5 | 63 | 2 |
| Name3 | 73 | 38 | 3 |
+--------------+--------------+-----------+----------+

Answer 3

This simple query averages Test1 and Test2. Depending on your dbms, you might have trouble with reserved words like name.
select name, cast(avg(average) as integer)
from test
where exam = 'Test1'
or exam = 'Test2'
group by name;
This simple query gives you the values for "main".
select name, average as main
from test
where exam = 'Main'
Put them together in a common table expression, and join on "name".
with test_avg as (
select name, cast(avg(average) as integer)
from test
where exam = 'Test1'
or exam = 'Test2'
group by name
), main_avg as (
select name, average as main
from test
where exam = 'Main'
)
select t1.name, t1.avg, t2.main
from test_avg t1
inner join main_avg t2
on t1.name = t2.name;
name avg main
--
Name1 61 89
Name2 50 63
Name3 73 38
I don't know what you mean by position. If you're trying to rank the rows from highest average to lowest average, you might do it like this.
with test_avg as (
select name, cast(avg(average) as integer)
from test
where exam = 'Test1'
or exam = 'Test2'
group by name
), main_avg as (
select name, average as main
from test
where exam = 'Main'
)
select t1.name, t1.avg, t2.main, row_number() over (order by avg desc) as position
from test_avg t1
inner join main_avg t2
on t1.name = t2.name
order by position;
name avg main position
--
Name3 73 38 1
Name1 61 89 2
Name2 50 63 3

Answer 4

You can play with the max here.... Its very simple
select a.*,row_number() over (order by main desc) as position from
(
select name,
AVG(case when exam in ('Test1','Test2') then Average else null end ) as testa,
max(case when exam in ('Main') then Average else null end) as main
from abc
group by name
) a
order by name;
Output :
name testa main position1
Name1 60.50 89 1
Name2 49.50 63 2
Name3 73.00 38 3