database connection from dll

[susuke]

Hi!

I want ot create functions in a dll (in bcb5), to use datas from a database with ODBC connection.

How can i do this?

I try to create a data module inside a dll, and create a TDatabase object, and the dll was compiled succesful, but when i tried to call the dll function (it creates and closes an ODBC connection only) from a program was created with c++ builder 5, an error message appeared:

"Acces violation on ...."

Please help me to solve this problem.

Thanx

 

[2ffat]

Instead of using a data module have you:
1) tried dropping the db component right on the dll form, or
2) tried creating a virutal connection via new, delete?

I'm not that familar with DLL's. Sorry.

James P. Cottingham
-----------------------------------------
[sup]To determine how long it will take to write and debug a program, take your best estimate, multiply that by two, add one, and convert to the next higher units.[/sup]

 

[butthead]

if you are not familiar with creating dll go through the
online help in builder and do the dll create example. then go to google and do a search for creating dll.

you have to pass the data from the dll to your app.
I dont know if you can pass handles and such. I would use the dll to handle the opening and closing of the database and all data retrieval. then I would use wrapper functions
to transmit the individual records to the app.

this could be cumbersome if you are trying to populate a
stringgrid, but if you only need one record at a time the
individual records could be parsed and delivered as character arrays.



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