RE: A sequence, by any other name
- Posted by matthewwalkerlewis at YAHOO.COM Feb 28, 2001
- 393 views
> -----Original Message----- > From: Jonas Temple [mailto:jktemple at yhti.net] > - Include the data type as part of the TABLEDEF information, as you > stated you are considering. I'll probably add a second field to TABLEDEF: DATATYPES or some such. I'm also automating the table/field creation process somewhat, so the user should never have to touch TABLEDEF directly. Once indices come along, there will be another system table: INDEXDEF, to keep track of indexed fields. This should speed up queries over large databases MUCH faster. > - Since ODBC doesn't handle sequences how about the EUSQL/EDS ODBC > driver expand the record down to the lowest sequence? Heck, you could > even write the ODBC driver for EDS and not have to continue to support > EUSQL. Well, the only problem with that is that ODBC drivers give you access to the DBMS. Unfortunately, there isn't really anything comparable to a DBMS for EDS (EuSQL notwithstanding :). I'll still need to have the code for EuSQL to do the manipulations. > For example, take the following sequence: >TABLEDEF: >{{{"First Name"},{"Last Name"}},{{"123"},{"456"},{"7890"}}} > Full Name Phone numner >a select * would return: >{"First Name", "Last Name", "123", "456", "7890"} I thought about doing this, but opted for the simplicity of returning "*", since there could be many nested sequences. I'd need to flatten out the record, which might be a good idea. > Anyway, to sum up what my previous post said, my thoughts are: > - When returning the field defenitions return the "lowest" field > definition. In other words, don't return the name of a sequence that > contains other sequences. > - When returning the data elements return the "lowest" field value. Yep, that's basically what I'm thinking. > Oh by the way, I looked at the documentation on MSDN and ran > screaming > when I saw the specifics about writing an ODBC driver. I > think it would > be great to have and EDS ODBC driver but the sequence thing will be a > hurdle. Like I rambled in my other post, you could stop supporting > EUSQL and go to strictly ODBC. However, some non-Windows folks might > still want EUSQL. Since the code would all be in Eu, it should be portable to linux as an .so, at least. I also just fixed a bug regarding the handling of conditions. It wasn't looking at the correct fields if all fields in a table weren't consecutive in the SQL statement (ie, if there was a field from another table mixed in the order). Matt Lewis