Background

The ODBC API matches up on the backend to an ODBC compatible data source. This could be anything from a text file to an Oracle RDBMS.

The backend access come from ODBC drivers, or vendor specifc drivers that allow data access. PostODBC is such a driver, along with others that are available, such as the OpenLink ODBC drivers.

Once you write an ODBC application, you SHOULD be able to connect to ANY back end database, regardless of the vendor, as long as the database schema is the same.

For example. you could have MS SQL Server and PostgreSQL servers which have exactly the same data. Using ODBC, your Windows app would make exactly the same calls and the back end data source would look the same (to the windows app).

In the real world, differences in drivers and the level of ODBC support lessens the potential of ODBC:

If I write an app for PostgreSQL can I write it using ODBC calls to the PostgreSQL server, or is that only when another database program like MS SQL Server or Access needs to access the data?

Again, the ODBC API set is the way to go. You can find out more at Microsoft's web site or in your Visual C++ docs (if that's what you are using.)

Visual Basic and the other RAD tools have Recordset objects that use ODBC directly to access data. Using the data-aware controls, you can quickly link to the ODBC back end database (very quickly).

Playing around with MS Access will help you sort this out. Try using File->Get External Data

TIP: You'll have to set up a DSN first.

TIP: The PostgreSQL datetime type will break MS Access.