Step 7: The Query Document

The query builder makes it fast and easy to create some Web applications. To take advantage of the complete set of features available in Tango, you can edit the query document directly. Tango query documents contain instructions telling the Tango Application Server how to query a database and how to format the results. Query documents are made up of a series of one or more "actions", each of which performs a specific function and can have results in the form of HTML associated with it. When a query document is called, the actions within it are executed by the Tango Application Server sequentially. When the end of the query document is reached, the results are returned to the user.

There are several different kinds of actions. In addition to ones for searching, inserting, updating and deleting records, there are actions for calling external applications through DLLs or UNIX executables, executing custom SQL statements, and controlling the flow of execution within a document.