Info on non-embedded SQL from C

I have a C program that generates standard SQL (**) at run time based on user input and executes against a preexisting database. It is currently implemented to use Sybase, although I designed it (hopefully) to allow other SQL engines to be used easily. All I need from the RDBMS is the ability to execute a single SQL SELECT statement and read the resuling rows back. In Sybase, I can do this by building a null-terminated C string with the SQL statement, calling dbcmd(), dbexec(), and dbresults(). I cannot use an embedded SQL system because I do not know the SQL statements to be used at compile time. My question is: What commercial database systems provide this functionality on Unix platforms? I initially assumed that they all would, since it appears to be such a simple and common approach; however, I was stunned when an Informix rep told me that what I wanted to do was impossible with their system. However, I also got the impression that the Informix rep was an idiot, so I don't want to take that as the last word. Any information will be appreciated. Thanks. Barry Jaspan, bjaspan@aktis.com Geer Zolot Associates / Aktis, Inc. ** I do not claim to be an SQL guru. My working definition for "standard SQL" is that it allows the following statement syntax: INSERT INTO table_name VALUES (expr_list) SELECT column_list FROM table_list WHERE condition_list GROUP BY column_list HAVING condition_list(plus aggrs) ORDER BY column_list I also assumed that all commercial RDBMs would support standard SQL, perhaps this is also incorrect.