BDE Overview

The Borland Database Engine (BDE) is a data-access mechanism that can be shared by several applications. The BDE defines a powerful library of API calls that can create, restructure, fetch data from, update, and otherwise manipulate local and remote database servers. The BDE provides a uniform interface to access a wide variety of database servers, using drivers to connect to different databases. The components on the BDE category of the Tool Palette enable you to connect to database information using the BDE.

When deploying BDE-based applications, you must include the BDE with your application. While this increases the size of the application and the complexity of deployment, the BDE can be shared with other BDE-based applications and provides a broader range of support for database manipulation. Although you can use the API of the BDE directly in your application, the components on the BDE category of the Tool Palette wrap most of this functionality for you.

The main BDE components are:

Components	Function
TTable	Retrieves data from a physical database table via the BDE and supplies it to one or more data-aware components through a DataSource component. Conversely, it also sends data received from a component to a physical database via the BDE.
TQuery	Uses SQL statements to retrieve data from a physical database table via the BDE and supplies it to one or more data-aware components through a TDataSource component. Conversely, it uses SQL statements to send data from a component to a physical database via the BDE.
TStoredProc	Enables an application to access server stored procedures. It sends data received from a component to a physical database via the BDE.
TDatabase	Sets up a persistent connection to a database, especially a remote database requiring a user login and password.
TSession	Provides global control over a group of database components. A default TSession component is automatically created for each database application. You must use the TSession component only if you are creating a multithreaded database application. Each database thread requires its own session component.
TBatchMove	Copies a table structure or its data. It can be used to move entire tables from one database format to another.
TUpdateSQL	Lets you use cached updates support with read-only datasets.
TNestedTable	Retrieves the data in a nested dataset field and supplies it to data-aware controls through a datasource component.