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.

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

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.

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

SQL Server 2016 lets you treat JSON objects like rows in a table, allowing you to use data from AJAX queries in joins, updates and any other SQL statement you can think of.

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

SQL and the Web Many popular websites are backed by SQL databases, which they use to pull user-specific data and data responsive to particular user queries as people navigate their sites.