ASA SQL Reference
  SQL Language Elements

Comments

Comments are used to attach explanatory text to SQL statements or statement blocks. The database server does not execute comments.

Several comment indicators are available in Adaptive Server Anywhere.

• -- (Double hyphen)    The database server ignores any remaining characters on the line. This is the SQL/92 comment indicator.

• // (Double slash)    The double slash has the same meaning as the double hyphen.

• /* ... */ (Slash-asterisk)    Any characters between the two comment markers are ignored. The two comment markers may be on the same or different lines. Comments indicated in this style can be nested. This style of commenting is also called C-style comments.

• % (Percent sign)    The percent sign has the same meaning as the double hyphen, if the PERCENT_AS_COMMENT option is set to ON. It is recommended that % not be used as a comment indicator.

Standards and compatibility 

• The double-hyphen and the slash-asterisk comment styles are compatible with Adaptive Server Enterprise.

Examples 

• The following example illustrates the use of double-dash comments:

  CREATE FUNCTION fullname (firstname CHAR(30),
           lastname CHAR(30))
  RETURNS CHAR(61)
  -- fullname concatenates the firstname and lastname
  -- arguments with a single space between.
  BEGIN
     DECLARE name CHAR(61);
     SET name = firstname || ' ' || lastname;
     RETURN ( name );
  END

• The following example illustrates the use of C-style comments:

  /*
     Lists the names and employee IDs of employees
     who work in the sales department.
  */
  CREATE VIEW SalesEmployee AS
  SELECT emp_id, emp_lname, emp_fname
  FROM "DBA".employee
  WHERE dept_id = 200