Setting Connection Parameters for a Client Connection

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Setting Connection Parameters for a Client Connection

The following example shows one way to set default connection parameters. Assume that the system-default connection parameters are as follows.

System-Default Parameter	Parameter Value
Default database server	joe (INFORMIXSERVER environment variable is set to joe.)
Default user	tester
Default user password	No password
Callbacks enabled?	Yes (system default)
Pointers checked?	Yes (system default)

The following code fragment uses DataBlade API functions to change the following default system values.

DataBlade API Function	Default Parameter	Default Value
mi_set_default_connection_info( )	Database server name	beth
mi_set_default_connection_info( )	Server port = 0	None
mi_set_default_database_info( )	Database name	template1
	User-account name	miadmin
	User-account password	No password

extern void MI_PROC_CALLBACK all_callback( );
MI_CONNECTION                     *conn;
MI_CONNECTION_INFO                     conn_info;
MI_DATABASE_INFO                     db_info;

/* Initialize DataBlade API */
mi_register_callback(conn, MI_Exception, all_callback,
   NULL, NULL);

/* Assign default connection parameter in the 
 * connection-information descriptor
 */
conn_info.server_name = "beth";
conn_info.server_port = 0;

/* Set default connection parameters for the application */
if ( mi_set_default_connection_info(&conn_info) == MI_ERROR )
      printf("FAILED: mi_set_default_connection_info( )\n");

/* Assign default database parameters in the 
 * database-information descriptor
 */
db_info.user_name = "miadmin";
db_info.database_name = "template1";
db_info.password = NULL;

/* Set default database parameters for the application */
if ( mi_set_default_database_info(&db_info) == MI_ERROR )
      printf("FAILED: mi_set_default_database_info( )\n");

/* Get default connection and database parameters for
 * application
 */
mi_get_default_connection_info(&conn_info);
mi_get_default_database_info(&db_info);

/* Make sure the right database server is set as the default */
if ( strcmp("beth", conn_info.server_name) != 0 )
   printf("FAILED: got server_name %s, should be beth\n",
      conn_info.server_name);

/* Connect to database server 'beth' */
conn = mi_server_connect(&conn_info);
if ( conn == NULL )
   printf("FAILED: CONNECT to beth\n");
else
   {
   printf("OK: connected to %s\n", conn_info.server_name);
}

After these new defaults are established, the application calls mi_server_connect( ) to request a connection to the beth database server. If this request is successful, the application opens the template1\. For more information on mi_server_connect( ), see Connections with mi_server_connect( ).