Connecting to a database requires that you know its name and use the name to obtain a handle from the QDB client library that your application links with.
The name is used in the device path provided to the connection function:
qdb_hdl_t *dbhandle; // The QDB database handle dbhandle = qdb_connect("/dev/qdb/customerdb", 0); if (dbhandle == NULL) { fprintf(stderr, "Connect failed: %s\n", strerror(errno)); }