Tools to log into the Oracle database

The two most widely used tools to log into the database are SQL *Plus and SQL Developer.

Please Note that the tool iSQL *Plus which was introduced with Oracle 9i is dropped with the release of Oracle 11g.

SQL *Plus:

It’s a client server tool for connecting to the database server and running ad hoc SQL queries or PL/SQL. This tool is available with all the various databases for different platforms, and can communicate with the database server through the Oracle Net protocol, independent of the platform (O/S) on which the client(SQL *Plus) or the server (Oracle) is installed.

In Linux installation this can be found typically in a location like /u01/app/oracle/product/db_1/bin/sqlplus

And three environment variables must be set  

ORACLE_HOME : Where the oracle software is installed.

PATH : The path to the bin directory in the Oracle home.

LD_LIBRARY_PATH : The lib directory of the Oracle home.

In windows installation there used to be 2 versions the CUI (sqlplus.exe) and GUI (sqlplusw.exe). Now the GUI version is no longer available.

In typical windows 7 installation the .exe is to be found at location

C:\app\<USERNAME>\product\11.2.0\dbhome_1\BIN\sqlplus.exe

Shortcut for which is

START >> Programs >> ORACLE HOME >> Application Development >> SQL Plus

The SQL Developer

It’s a GUI java tool (requires JRE for running), to connect to the Oracle or some non-oracle databases. It’s used to fire ad hoc SQL queries or to manage the PL/SQL Objects. Multiple connections can be open simultaneously.