Cross database query engine with Oracle

[majorwoody]

And for your last question, think of it this way. The users of this application will log in using TNS aliases. And each alias has different privileges. These privileges will prohibit some users from accessing some tables. That's why I was asked not to use database links.

I don't understand the problem with database links. You have two schemes and different users. You can make a database link and give synonyms for tables in the linked database. And finally you can grant or revoke access to tables in the database and the linked database for every user.

But in order to make cross database queries, i have to do it manually each time, which is a very hectic task. so I want to develop an common interface (possibly an API) and call some methods to make these queries

You have to create your own QAbstractTableModel like QCrossSqlQueryModel, which gets two queries on two connections.

[kasper360]

I don't understand the problem with database links. You have two schemes and different users. You can make a database link and give synonyms for tables in the linked database. And finally you can grant or revoke access to tables in the database and the linked database for every user.

Thanx for this info. I'm not much familiar with database links because this is the 1st time I've even considered to use them in an application. I'll discuss this with my employer and see if there are any other causes why he wants me not to use it.