Re: Q: Portability of ESQL between Informix and Sybase

All, In article <4aqjrn$i3i@cloner2.ix.netcom.com> maxw@ix.netcom.com(Max "Max Welton" writes: > In <4amtc6$n3s@panix.com> edwinb@panix.com (Edwin Babadaglian) writes: > > > >I am developing an app with Informix ESQL/C 7.1 and I would like to > port > >to Sybase. I will primarily make use of insert and update cursors and > avoid > >vendor extensions as much as possible. As I am new to ESQL/C > development > > We are currently using ESQL in Sybase (version 10.0.3). Avoiding vendor > extensions is an excellent idea! The more you use the proprietary > stuff, the RDBMS vendor becomes entrenched in your project. Keep your > options open! > > Most vendors document (or can tell you) which features are > non-standard. Sybase SQL in system-10 (Transact-SQL) is supposed to be > complient with SQL-89, but I think there is a later spec (SQL-92?) that > supports stored-procedures. > There are several things you need to do. 1) Avoid straight forward extensions. 2) Avoid those constructs implemented differently than the description given in the SQL/2 (ISO 9075:1992) standard 3) Only use those constructs that are provided by other vendors and also meet criterion (2) above for those vendors. If you are interested in having a tool help you with this process I will be happy to tell you more about OSPC (Open Systems Portability Checker), which has supported embedded SQL for over a year now. Most vendors handle Entry level SQL/2 (which corersponds to SQL/1) reasonable well. Implementation of Intermediate level SQL/2 seem to vary. Now that NIST have a test suite for Intermediate level perhaps vendors will have some incentive to start following the standard. derek