Returns FALSE on error, and an array upon success.
This function will return the list of avaible DNS (after calling it several times). The connection_id is required to be a valid ODBC connection. The fetch_type can be one of two constant types: SQL_FETCH_FIRST, SQL_FETCH_NEXT. Use SQL_FETCH_FIRST the first time this function is called, thereafter use the SQL_FETCH_NEXT.