SQL comments

Static SQL statements can include host language or SQL comments. Dynamic SQL statements can include SQL comments.

There are two types of SQL comments:

simple comments: Simple comments are introduced by two consecutive hyphens (--) and end with the end of line.
bracketed comments: Bracketed comments are introduced by /* and end with */.

The following rules apply to the use of simple comments:

The two hyphens must be on the same line and must not be separated by a space.
Simple comments can be started wherever a space is valid (except within a delimiter token or between 'EXEC' and 'SQL').
Simple comments cannot be continued to the next line.
In COBOL, the hyphens must be preceded by a space.

The following rules apply to the use of bracketed comments:

The /* must be on the same line and must not be separated by a space.
The */ must be on the same line and must not be separated by a space.
Bracketed comments can be started wherever a space is valid (except within a delimiter token or between 'EXEC' and 'SQL').
Bracketed comments can be continued to subsequent lines.

Examples

Example 1: This example shows how to include simple comments in a statement:

   CREATE VIEW PRJ_MAXPER       -- PROJECTS WITH MOST SUPPORT PERSONNEL
     AS SELECT PROJNO, PROJNAME -- NUMBER AND NAME OF PROJECT
       FROM PROJECT
       WHERE DEPTNO = 'E21'     -- SYSTEMS SUPPORT DEPT CODE
       AND PRSTAFF > 1

Example 2: This example shows how to include bracketed comments in a statement:

   CREATE VIEW PRJ_MAXPER       /* PROJECTS WITH MOST SUPPORT
                                     PERSONNEL                 */
     AS SELECT PROJNO, PROJNAME /* NUMBER AND NAME OF PROJECT  */
       FROM PROJECT
       WHERE DEPTNO = 'E21'     /* SYSTEMS SUPPORT DEPT CODE   */
       AND PRSTAFF > 1