Join ... using keywords should be used to specify how the tables should be linked.
2. join ... using
Step-by-step explanation:
If table is has to be linked it can be connected normally as outer join with same column name.
Purpose of outer join is to fetch the matched records among the table and get the relevant records from table.
People can also use select statement with “IN” sub query, if we use “IN” query execute very slow during the fetching the matched records.
As good practice join using is used in same column name is available across the table.
By using join using in query end user can set some query conditions also.