>I learned programming with SQL server from vfp help. i didn't see a information like it another language's help.

I worked with an Oracle Rdb database (not "regular" Oracle) for a while a few years back when I knew less SQL than I do now. There was no documentation available but it accepted ANSI standard SQL so I got "Joe Celko's SQL For Smarties" (second edition) and used it for reference. It helped me understand much more about the SQL language.