MySQL - Postgres: Wrapping multiple rows into one

Question

Here is an example of the current rows as is:

id    sdate    subject    exam1    assgn1    overallmark    result    credits
____________________________________________________________________________
 1    082013   Math      40.0      0.00       33             F         7.50
 2    082013   Math      0.0       25.00      33             F         7.50
 3    082013   Science   80.0      0.00       76             P         7.50

And this is what i want it to be:

id    sdate    subject    exam1    assgn1    overallmark    result    credits
____________________________________________________________________________
 1    082013   Math      40.0      25.00       33             F         7.50

Essentials i want to wrap multiple results of the same subject into one row, what would be the best way to go about this? I've attempted using GROUP_CONCAT but my mysql knowledge isn't exactly up to scratch.

I've been using a simple MySQL query to get this results displayed in my first code block:

SELECT * FROM exam_results WHERE sdate = :sdate AND studno = :studno

Edit*

Thanks to user @echo_Me this solution works:

select id ,sdate,subject,sum(exam1)exam1,sum(assgn1)assgn1,overallmark,result,
credits from exam_results group by studno,subject

However, could the same syntax be used in postgres? How would i change it accordingly to fit in with a postgres installation?

Answer 1

try that:

  select id ,sdate,subject,sum(exam1)exam1,sum(assgn1)assgn1,overallmark,result,
  credits
  from exam_results
  group by studno,subject

Answer 2

I'm not sure what you're trying achieve but you can take a look at this post about group concat: CONCAT with GROUP_CONCAT in mysql

From your expected result I don't really see a group_concat need. If you want to get the min value of exam1 just Group By credits or sDate and select MIN(exam1). The group concatenation is used when you want to have values from different rows returned in one. E.g: have overall mark = 33,33,76