18.1.1 Flow of application program processing

The following figure shows the flow of application program processing for manipulating a database.

Figure 18‒1: Flow of application program processing for manipulating a database

Connecting to the HADB server

To manipulate a database from an application program, you must connect the application program to the HADB server. You do this by first allocating a connection handle for uniquely identifying the connection to the application program. Next, you use this connection handle to establish the connection. The application program is then connected to the HADB server.

You can also establish multiple connections from the same application program. The maximum number of connections that can be established concurrently is fixed.

Note that you must start an HADB server before you connect an application program to it.

Once an application program is connected to the HADB server, it can use SQL statements to manipulate the database.

Disconnecting from the HADB server

Before you terminate the application program, make sure that you disconnect it from the HADB server. First, close the connection and then release the connection handle. The application program is then disconnected from the HADB server, so that you can terminate the application program.

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