query for summing up values present in different columns in sql server 2005

Question

i have columns i.e. theory marks, pratical marks, student's Id ,course Id ,& subject Id i need to add up the vaules present in columns theory marks & practical marks in order to get the aggregate, i dont know how to add the column values though. I am using sql server 2005

please help

Answer 1

assuming theory marks and practical marks are numerical data types

SELECT
    student_id,
    course_id,
    subject_id,    
    SUM(theory_marks + practical_marks) AS overall_mark
FROM
    table
GROUP BY
    student_id, course_id, subject_id