Author: S S B Magesh Puvananthiran
One of the ways to set runtime database parameters to the TSQLConnection component
Since Borland is now giving more importance to dbExpress and trying to get rid of
BDE in future releases, we used dbExpress in that project. I have seen a whole lot
of threads discussing/comparing the features of dbExpress with BDE in our Borland
newsgroups; it's really interesting.
Even though there are a lot of benefits using dbExpress, I liked the following
features of dbExpress:
1. Changing between databases:
If you want your application to point to a new database, then all you need to do is
to change the entries in the dbxconnections.ini file and in the code, you need to
call the LoadParamsFromIniFile method. But you may need to set the following
properties of the TSQLConnection component:
I used a procedure like this:
1 procedure Connect;
2 begin3 SQLConnection1.ConnectionName := 'Oracle';
4 SQLConnection1.DriverName := 'Oracle';
5 SQLConnection1.GetDriverFunc := 'getSQLDriverORACLE';
6 SQLConnection1.VendorLib := 'OCI.DLL';
You can get all those values as parameters to the application. Or the other option
I would see is to add these properties as part of the dbxconnections.ini file and
read it from there. Even though I have not tried this option, I hope this would
Another important thing to note is that if you are setting these properties at
runtime, you need to make sure that the LoadParamsOnConnect property of
TSQLConnection be false.
After setting all those parameters and setting the Connected property to True will
establish a connection to the database. But for some reason, if you provide some
wrong parameters and try to set the Connected property to True at runtime somehow
passes. I heard that this is a bug in dbExpress and been fixed in Delphi 6. But I
doubt it's been fixed in Delphi 6 since I tried with Delphi 6 only. Instead I used
the ConnectionState property of the TSQLConnection component. It seems to work
fine. Let me know if I'm wrong.
2. Easy Deployment - lightweight:
Deploying an dbExpress application requires the relevant database driver files and
the dbxconnections.ini file. But for BDE applications, we need to install the BDE
and create a relevant Aliases for the databases.
3. What I would like to know?
I have used BDE before and there is a session component available that you can attach to the database component but in dbExpress, I dont see such a component. Is there any way we can achieve the same with dbExpress component? Feel free to share your thoughts on this.