In --> Group By with Multiple columns...> how it will responds

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In --> Group By with Multiple columns...> how it will responds

r.dilliprasad

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Points: 51
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February 22, 2013 at 12:11 pm

#394245

can any please help me...!
Thanks & Regards
Prasad Reddy

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Lowell SSC Guru Points: 323504 More actions · Answer 1

the title of your post "In --> Group By with Multiple columns...> how it will responds " is not enough for us to go by;

can you explain your question better? do you have a coded example that's not working as expected?

Lowell

--help us help you! If you post a question, make sure you include a CREATE TABLE... statement and INSERT INTO... statement into that table to give the volunteers here representative data. with your description of the problem, we can provide a tested, verifiable solution to your question! asking the question the right way gets you a tested answer the fastest way possible!

r.dilliprasad Valued Member Points: 51 More actions · Answer 2

query is

select col1, col2, col3.... from table

Group BY Colm, Coln

Here my question is :: while we take 2 or more colmuns in Group By..

Actually how it works

dgowrij SSC Veteran Points: 234 More actions · Answer 3

Below is a basic example for Group By

CREATE TABLE #Studentcourseschedule(

Department int,

Courseid int,

studentid int)

go

insert into #Studentcourseschedule(Department, Courseid,studentid)

values(1,1,1)

,(1,2,1)

,(1,3,1)

,(1,1,5)

,(1,3,6)

,(1,1,7)

,(2,2,1)

,(2,1,2)

,(2,3,2)

go

select department, COUNT(studentid) Studentcount

from #Studentcourseschedule

group by department

order by Department

go

select department, courseid, COUNT(studentid) Studentcount

from #Studentcourseschedule

group by department,courseid

order by Department, Courseid

1st Query Result:

department Studentcount

1 6

2 3

2nd Query Result

departmentcourseidStudentcount

1 1 3

1 2 1

1 3 2

2 1 1

2 2 1

2 3 1

In the first query the grouping is done only on Department, so it checks the no of students in each of the Department available in the table which is 1 and 2 in example

When we add another group by column on courseid, now it looks for the each course available under each department and displays count of the student in that department and course.