The difference between union and group is as follows:
take two tables t1 and t2.in t1 we have columnss like a,b,c,d. and t2 has a,d,e,f.so union means t1 union t2 i.e getting result from both tables i.e a,b,c,d,e.,f
where as group performs on a indiviual column in a particular table.
Union:- is used to combine the data of more than two tables which are having same structure
Group:- is used to combine same type of data of a perticular column of table
Answered By: Chandra Date: 5/6/2008