Comments

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

The following comment indicators are supported in SQL Anywhere:

-- (Double hyphen) The database server ignores any remaining characters on the line. This is the SQL/2008 comment indicator. You can add and remove this comment indicator by pressing Ctrl+minus sign in Interactive SQL and in the Stored Procedure window of Sybase Central. See Interactive SQL keyboard shortcuts.
// (Double slash) The double slash has the same meaning as the double hyphen. You can add and remove this comment indicator by pressing Ctrl+forward slash in Interactive SQL and in the Stored Procedure window of Sybase Central. See Interactive SQL keyboard shortcuts.
/* ... */ (Slash-asterisk) Any characters between the two comment markers are ignored. The two comment markers can 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.

Examples

The following example illustrates the use of double-hyphen 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 SalesEmployees AS
   SELECT EmployeeID, Surname, GivenName
   FROM Employees
   WHERE DepartmentID = 200;

Standards and compatibility

SQL/2008 The use of double-minus signs for a comment is a core feature of the ANSI SQL/2008 standard. The use of C-style, bracketed comments (/* ... */) is SQL language feature T351 of the SQL/2008 standard. Double-slash comments (//) are supported as a vendor extension.

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