Qualified Join Clause
Group/Order Expression Clause
Joined Table Expression Clause
( joined table expression )
A joined table expression can optionally be enclosed by parentheses. The use of parentheses does not affect the order of processing in this case, since only the AND operator can be used to combine join predicates.
The join condition consists of two value expressions being compared. Either value expression can range from a simple column name to a complex, nested expression involving arithmetic combinations of columns, functions, and constants. Both of the value expressions being compared must reference at least one column from one or the other table being joined.
Multiple join predicates can be combined using the AND Boolean operator only. That is, OR conditions are not permitted in the joined table expression clause.