Strict variable identification in SQL statements

Program variable identification in static SQL statements is more strict in version 2.20 than older versions.

If you define a variable with the same name as an SQL object (i.e. table name, table alias), the fglcomp compiler will raise an error because it will consider the program variable first. For example, if the variable name matches the table or alias identifier, using table.column in the SQL statement will be resolved as variable.member, which does not exist.

The next code example will not compile because the program defines a variable using the same name as the table alias c:

MAIN
   DEFINE c INTEGER
   DATABASE stores 
   SELECT COUNT(*) INTO c
      FROM customer c 
         WHERE c.fname IS NULL
END MAIN

The code also fails to compile with IBM® Informix® 4GL 7.32, but it did compile with version of Genero Business Development Language.

To work around this, you must either rename the program variable, or explicitly identify SQL objects with the @ prefix in the SQL statement:

MAIN
   DEFINE c INTEGER
   DATABASE stores 
   SELECT COUNT(*) INTO c
      FROM customer c 
         WHERE @c.fname IS NULL
END MAIN

Recompile all your programs to find the conflicts.