Web pages can’t directly access the data stored in a database. Instead, they interact with a recordset. A recordset is a subset of the information (records), extracted from the database using a database query. A query is a search statement designed to find and extract specific information from a database. Dreamweaver uses the Structured Query Language (SQL, pronounced “sequel”) to build queries. Although you don’t need to learn SQL to create simple queries using Dreamweaver, a basic knowledge of this language lets you create more advanced queries, and provides you with greater flexibility in designing dynamic pages.

A SQL query can produce a recordset that includes only certain columns, only certain records, or a combination of both. A recordset can also include all the records and columns of a database table. However, because applications rarely need to use every piece of data in a database, you should strive to make your recordsets as small as possible. Because the web server temporarily holds the recordset in memory, using a smaller recordset uses less memory, and can potentially improve server performance.