Which two statements are true regarding the USING clause in table joins? (Choose two .)
A.
It can be used to join a maximum of three tables.
B.
It can be used to restrict the number of columns used in a NATURAL join.
C.
It can be used to access data from tables through equijoins as well as nonequijoins.
D.
It can be used to join tables that have columns with the same name and compatible data types.
option D is wrong:
correct statement is :
It can be used to join tables that have columns with the same name and “INcompatible” data types.
Option d is wrong
I think option C and D are correct. USING cannot be used with NATURAL JOIN. So, B is wrong. A is definitely wrong.
In my opinion A and B are wrong
I can’t understand B sentence.
Really Probably C and D correct
The correct answer it´s D, you can´t use a using clause in a NATURAL JOIN
http://docs.oracle.com/javadb/10.8.3.0/ref/rrefsqljnaturaljoin.html
C is also incorrect. An equijoin is a join with a join condition containing an equality operator (=).