Kiran Dalvi05 Nov, 20210 Comments42 Secs ReadORA-12502 TNS-12502 TNS:listener received no CONNECT_DATA from client ORA-12502 TNS-12502 TNS:LISTENER RECEIVED NO CONNECT_DATA FROM CLIENT TNS:listener received no CONNECT_DATA from client Cause:No CONNECT_DATA was passed to the listener. Action: Check that the service name resolved from TNSNAMES.ORA has the CONNECT_DATA component of the connect descriptor. Below is the sample entry of tnsnames.ora:- #When using SERVICE_NAME in CONNECT_DATA component orcl.example.com = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = myserver.example.com)(PORT = 1521)) ) (CONNECT_DATA = (SERVICE_NAME = orcl) ) ) #When using SID in CONNECT_DATA component orcl.example.com = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = myserver.example.com)(PORT = 1521)) ) (CONNECT_DATA = (SID = orcl) ) ) So for the service name please ensure you have the CONNECT_DATA clause in the tnsnames.ora, if you don’t have one please choose a SERVICE_NAME or SID clause. Oracle DBATechnology BlogShare: ORA-00904 ERROR MESSAGE “INVALID IDENTIFIER”ORA-00257: archiver error. Connect internal only, until freed.