Keywords and user-defined identifiers that are used in an SPL program are case insensitive. For example, the statement DBMS_OUTPUT.PUT_LINE('Hello World'); is interpreted to mean the same thing as dbms_output.put_line('Hello World');, Dbms_Output.Put_Line('HelloWorld');, or DBMS_output.Put_line('HelloWorld');.

However, character and string constants, data retrieved from the PolarDB-O, or data obtained from other external sources are case sensitive. The following output is generated by the DBMS_OUTPUT.PUT_LINE('Hello World!') ; statement:

Hello World!

However, the following output is generated by the DBMS_OUTPUT.PUT_LINE('HELLO WORLD!') ; statement:

HELLO WORLD!