You can query across databases in Oracle and Sql Server, with a little work. I'm not sure about access. <BR>It really would be easier to just link the tables I would think.

Query is a request for data. In this article we are going to explain how to create and modify query in Microsoft Access the easy way.

That means they’re faster than Access queries. Transact-SQL (T-SQL) provides procedural extensions to SQL, allowing you to build more sophisticated queries.

i'd like to make a query in access (and eventually SQL 2k) that will combine a table of activities (each row with a unique activityID and activityName) along with a table of activityToUsers (each ...

Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement.

PostgreSQL foreign data wrappers are a great way to expose APIs to SQL. And SQL is a great way to reason over the data.