Question

What is the Cartesian product? How is it different from join operation?

Answer 1

When you join two or more tables without any condition, it is called Cartesian product or Cross Join. The difference between Cartesian Product and Join is – In Join operation we have to mention the column name from both the tables on which join has to be perform for

eg. Select EmpName,Salary from Employee, SalaryRange where Employee.Salary =SalaryRange.MinSalary. Whereas in Cartesian product we do not mention any condition for

eg. Select a.Id,b.Id from Employee a,Manager b;