Data Provider

[Martin Wulfe]

As part of my job I use a proprietary data system using a software
package named CSPro. It maintains a hierarchical data file with a
separate data dictionary file.

I recently wrote a VB6 activex DLL to access these data files. The DLL
loads the dictionary, and based on the information from the dictionary,
it then loads the data into a "case" class. A case includes a
collection of objects called "variables", also based on a class.

My real objective is to provide the programmer with a data source
against which SQL can be applied, so the CSPro data can be accessed
directly from other applications. I can easily convert the "case" into
an ADO recordset, but I don't think that will help.

Can anyone suggest an approach to this?

Thanks in advance,

Martin

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[TC]

To provide SQL access to an arbitrary data store, you will presumeably have
to:
- parse the SQL;
- determine an optimized query plan;
- access the data store, using that plan, then
- form a result set to return to the caller.

So you will need:
- an SQL parser;
- a "query optimizer", and
- a query plan interpreter.

I'm sure that you could find an SQL parser somewhere. The difficulty would
be, all the rest of it. So I think the issue is, can you get a "black box"
product for some or all of the tasks above? The ideal would be, a product
which accepts a definition of your data store, plus an arbitrary SQL
statement, and returns a well-defined list of instructions for how to get
the right data, out of the store.

Unless I'm missing somehing obvious!

HTH,
TC
"Martin Wulfe" <mw****@yahoo.com> wrote in message
news:3f*********************@news.frii.net...

As part of my job I use a proprietary data system using a software
package named CSPro. It maintains a hierarchical data file with a
separate data dictionary file.

I recently wrote a VB6 activex DLL to access these data files. The DLL
loads the dictionary, and based on the information from the dictionary,
it then loads the data into a "case" class. A case includes a
collection of objects called "variables", also based on a class.

My real objective is to provide the programmer with a data source
against which SQL can be applied, so the CSPro data can be accessed
directly from other applications. I can easily convert the "case" into
an ADO recordset, but I don't think that will help.

Can anyone suggest an approach to this?

Thanks in advance,

Martin

*** Sent via Developersdex http://www.developersdex.com ***
Don't just participate in USENET...get rewarded for it!