Re: OpenIngres API

Steven Belbin (steven.belbin@consyst-sql.com) wrote: : GODS <gods@sky.net> wrote in article <34A20002.50F0@sky.net>... : > Has anyone done any Visual C++ / OpenIngres API examples besides what : > comes with the demo cd? : > : Yes (by the way some of their examples do not even compile correctly !!!). : The OpenIngres API is handful (as most database API tend to be), there are : some benefits versus ODBC and EMBEDDED SQL. Also like APIs it is designed : for C development therefore if you want nice object-oriented code, you have : to do it yourself. : Personally, I have seen and used better APIs, one thing that annoys my : about OpenIngres API is that the first SQL statement generates the : transaction ID, therefore you need to be carefull about comparing against : NULL, since a NULL transaction ID is acceptable in certain contexts. Also : the you have to juggle with the use of VARIABLE length data (Ingres : reserves the first two bytes for the length of the data), therefore you : cannot simply pass the address of where you want the data to reside, you : have to allocate a temporary variable, and copy n bytes (using the size : value inside the first two bytes) from the temporary variable with an : offset of two bytes into your destination address. : With LONG datatypes this becomes even more complex by retrieve the data : until everything has been read (however to be fair to OI API, so does ODBC : and most other APIs handles LONG datatypes in complex manners). : In conclusion, use API if you really need to mostly for performance gains, : and multi-platform environments, less dependency on ODBC vendors, and : sometimes there are some API operations that are almost impossible with : E/SQL and ODBC, such as backup & restoring a database, two-phase commits, : restarting a transaction, etc...