How to Group the Results in Sqlplus Oracle

Question

I want to show the BookTitle, Firstname along with a COUNT of Copies. When I run the query, it gives an error saying to group. But when I group it says not a expression to group. Can someone help me?

SELECT bk.BookTitle, au.FirstName, COUNT(bkc.BookCopyID), rb.ReservedDate 
FROM Book bk, Book_Author ba, BookCopy bkc, ReserveBook rb, Author au 
WHERE 
    bkc.BookID = bk.BookID 
    AND ba.BookID = bkc.BookID 
    AND ba.AuthorID = au.AuthorID 
    AND bkc.BookCopyID = rb.BookCopyID 
    AND rb.ReservedDate >= trunc(trunc(sysdate,'MON')-1,'MON') 
    AND rb.ReservedDate < trunc(sysdate,'MON') 
GROUP BY bkc.BookCopyID;

Answer 1

remove your group by statement and add this,

Group by bk.BookTitle,au.FirstName,rb.ReservedDate

Assuming all your where conditions are right and you know what you are doing.