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GNOME Data Access 3.0 manual | ![]() |
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libgda allows data sources (DSN) to be defined and refered to by a unique name which contains all the required information to actually open a connection (except the name and password if they are required). Of course it's still possible to open a connection without having defined a DSN, in which case a connection string is used to specify all the parameters resuired to open a connection. For more information about connection strings, see the gda_client_open_connection_from_string ()'s documentation.
Connections are created by a GdaClient object which can also manage connection pools. So the first step is to create a GdaClient object using gda_client_new (), and then use gda_client_open_connection () (or gda_client_open_connection_from_string () for connections not defined as DSN) to create connection objects (GdaConnection objects). Each connection object can then be used to actually execute queries, for example:
void do_stuff () { GdaClient *client; GdaConnection *connection; /* open a connection */ client = gda_client_new (); g_print ("CONNECTING\n"); connection = gda_client_open_connection (client, "calvaris", NULL, NULL, GDA_CONNECTION_OPTIONS_READ_ONLY); g_print ("CONNECTED\n"); /* use the connection */ execute_some_queries (connection); /* close the connection */ g_object_unref (G_OBJECT (connection)); g_object_unref (G_OBJECT (client)); }
Closing the connection can be ordered using gda_connection_close (), or is automatically done when the connection object is destroyed (as is the case in the example abive when g_object_unref() is called with the connection as argument).