The following code shows how to use the quoted identifier "MYNAME".
Without its enclosing double quotation marks, it is a valid identifier.
Therefore, the reference Hello is valid.
SQL> SQL> DECLARE-- from w ww .j av a 2 s .c om 2 "MYNAME" varchar2(10) := 'hello'; 3 BEGIN 4 DBMS_Output.Put_Line(Hello); 5 END; 6 / hello PL/SQL procedure successfully completed. SQL>
In the following code, the reference "Hello" is invalid, because the double quotation marks make the identifier case-sensitive.
SQL> SQL> DECLARE-- from w w w.j a va2 s . c o m 2 "MYNAME" varchar2(10) := 'hello'; 3 BEGIN 4 DBMS_Output.Put_Line("Hello"); 5 END; 6 / DBMS_Output.Put_Line("Hello"); * ERROR at line 4: ORA-06550: line 4, column 25: PLS-00201: identifier 'Hello' must be declared ORA-06550: line 4, column 3: PL/SQL: Statement ignored SQL>