Earlier versions of Informix Dynamic Server (IDS) had restriction with C-style comment indicators ( /* ... */ ) in SQL statements, within the DB–Access operations.



Without the C-style comment indicator it was not compliance with SQL-99 standard and caused problems while migrate from other databases server.



Starting with IDS Version 11.10, restrictions with C-style comment are no longer in effect. Any of the following styles SQL comment indicators can be use in all DB–Access statements.

• Double hyphen ( -- ) complies with the ANSI/ISO standard for SQL
• Braces ( { } ) are an Informix extension to the ANSI/ISO standard
• C-style slash-and-asterisk ( /* . . . */ ) comply with the SQL-99 standard

The comment symbol indicator can be choosing depends on ANSI/ISO compliance requirements.



Comment symbol indicator can be use on the same line with the SQL statement. It can spans across single-line or multiple-line, but cannot be nested.



DB-Access will filter any comments before sending SQL statement to the database server.

Examples:  -- Double hyphen comment  SELECT * FROM orders;     -- Selects all columns and rows                            -- from the orders table

  { Comment using braces }  SELECT * FROM orders;     {  Selects all columns and rows                               from the orders table  }

  /* C-style comment */  SELECT * FROM orders;     /* Selects all columns and rows                               from the orders table */

Sanjit Chakraborty