Question : ISQL, DSQL, SQL ??

What's the difference between ISQL and DSQL and SQL ???

Answer : ISQL, DSQL, SQL ??

SQL is Structured Querying Language.  It is basically a standard framework for retrieving information from databases.  So, theoretically once you know this standard, you can get information from any database.  ISQL is Informix SQL, which uses the standard SQL as its base but there are certain features unique to only Informix databases.  I'm not sure what DSQL is though, but probably its for another database or maybe dynamic Sql ?

HTH