Some applications have a single set of data. Others may have multiple data sets. For example, accounting applications often allow users to have different sets of data for different companies. Other common uses of multiple data sets are:

• archived and current data sets

• different data sets by year

• training, testing, and production data sets

By "set of data," we mean multiple instances of the same database structure but with different contents. Stonefield Query refers to a set of data as a "data source."

If you want to allow your users to query on different sets of data, set the Allow Multiple Data Sources setting to True. When this setting is True, the Login dialog displays a drop-down list of data sources defined to Stonefield Query and the File menu has an Open Database function (although it may appear as something other than "Open Database," depending on the value of the Description for Data Sources setting). These allow the user to choose which data source to query on.

How are different data sources defined to Stonefield Query? One of two ways:

• If the application's data is accessed by ODBC and there's a different ODBC data source defined (using the ODBC Data Source Administrator) for each set of data, you can set the User Can Manage Data Sources setting to True. This allows the user to select which of the ODBC data sources defined on their system are available to Stonefield Query.

• You can define a GetDataSources script for each database in the data dictionary that adds DataSource objects to the DataSources collection, specifying things like the data source type, location, name of the database, etc.