A join query without the join condition produces a cartesian product.

You can specify any type of condition, using any comparison operator in an equi-join.

Assertion. SQL SELECT's GROUP BY clause is used to divide the result in groups.

Reason. The GROUP BY clause combines all those records that have identical values in a particular field or in group by fields.

Assertion. A GROUP BY query can also include functions.

Reason. ALL SQL functions can be used in a GROUP BY query.