Comments about SQL scripts in Oracle DB (REM ,--,/**/)

SQL Script annotation syntax in Oracle DB

1. REM Single line comment
3. -- Single line comment
5. /* Single line comment */
7. /*
8. Multi Line
9. Comment
10. */

Supplement: REM is short for REMARK.

So what is the difference between REM and?

-- Or/**/can be used for PL/SQL, but REM [ark] cannot.

The following section can be executed successfully in SQL * PLUS.

1. REM comment
2. -- Comment
3. /* Comment */
4. Begin
5. DBMS_OUTPUT.PUT_LINE ('Test');-- Comment
6. DBMS_OUTPUT.PUT_LINE ('Test');/* Comment */
7. End;
8. /

But the following section won't work.

1. Begin
2. DBMS_OUTPUT.PUT_LINE ('Test'); REM comment
3. End;
4. /
6. Begin
7. REM comment
8. DBMS_OUTPUT.PUT_LINE ('Test');
9. End;
10. /

11.2 documentation on all comment types has a clear description of the annotations.

You can enter comments in a script in three ways:

• Using the SQL * Plus REMARK command for single line comments.

• Using the SQL comment delimiters/*... */for single or multi-line comments.

• Using ANSI/ISO (American National Standards Institute/International Standards Organization) comments--for single line comments.