Which three statements are true about the PESCRIBE command?
A.It can be used from SQL Developer. B.It displays all constraints that are defined for each column C.It can be used only from SQL*Plus D.It displays the PRIMARY KEY constraint for any column or columns that have that constraint. E.It displays the NOT NULL constraint for any columns that have that constraint. F.It can be used to display the structure of an existing view正确答案AEF
