How to connect sqlplus without tnsnames.ora

I always prefer to use TNSNAMES.ORA to connect to my database server. It is one of the most convenient way for the database servers who HOST Name or IP is fixed. If TNSNAMES.ORA has following entry

ORCL =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = ngarg.mydomain.co.in)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

TNS looks into "TNSNAMES.ORA" file to find out the meaning of "orcl" and connects Oracle Database Server Machine "ngarg.mydomain.co.in" on port 1521 "orcl" service when we fire following command like

C:\Users\nimish.garg>sqlplus scott/tiger@orcl
SQL*Plus: Release 11.2.0.3.0 Production on Tue Sep 30 14:24:03 2014
Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL>

There are times when we do not want to modify our TNSNAMES.ORA may be because we might want to connect a particular database service only for one time. So what are the other way possible to Connect to Oracle Database without using TNSNAMES.ORA? There are two ways for this:

1) EZCONNECT

EZCONNECT is Oracle's easy connect naming method. EZCONNECT eliminates the need for service name lookups in TNSNAMES.ORA files when connecting to an Oracle database across a TCP/IP network.

Syntax of EZCONNECT:

sqlplus username/password@[//]host[:port][/service_name]

Example:

C:\Users\nimish.garg>sqlplus scott/tiger@ngarg.mydomain.co.in:1521/orcl
SQL*Plus: Release 11.2.0.3.0 Production on Tue Sep 30 14:36:00 2014
Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Release 11.2.0.3.0 - 64bit Production

SQL>

To enable EZCONNECT "sqlnet.ora" should have naming methods "ezconnect" specified in NAMES.DIRECTORY_PATH Parameter. "sqlnet.ora" is located in $ORACLE_HOME/network/admin
Example:

NAMES.DIRECTORY_PATH=(ezconnect, tnsnames)

2) TNS Connect String
The TNS Connect String also known as Connect Descriptor is a type of connect identifier. It defines the parameters that need the Oracle Net Service to connect to a database service

Syntax of TNS Connect String

sqlplus "username/password@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=hostname)(PORT=port))(CONNECT_DATA=(SERVER=dedicated)(SERVICE_NAME=servicename)))"

in above syntax lower case letters must be replaced with the actual values. Please remember there should not be any space in the connect string, also no carriage return and in UNIX put the single quote instead of double quote.

Example

C:\Users\nimish.garg>sqlplus "scott/tiger@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=ngarg.mydomain.co.in)(PORT=1521))(CONNECT_DATA=(SERVER=dedicated)(SERVICE_NAME=orcl)))"

SQL*Plus: Release 11.2.0.3.0 Production on Tue Sep 30 15:05:13 2014
Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Release 11.2.0.3.0 - 64bit Production

SQL>

I hope you all have enjoyed reading this article. Please provide your valuable comments :)



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