常用的有三种方法：
方法一：v$version
SQL> select * from v$version;
BANNER
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Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
PL/SQL Release 11.2.0.1.0 - Production
CORE 11.2.0.1.0 Production
TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
方法二：product_component_version
select * from product_component_version;
VERSION
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STATUS
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NLSRTL
11.2.0.1.0
Production
Oracle Database 11g Enterprise Edition
11.2.0.1.0
Production
方法三：dbms_output.put_line( dbms_db_version.version )
SQL> SET SERVEROUTPUT ON
SQL> EXEC dbms_output.put_line( dbms_db_version.version );
11
PL/SQL procedure successfully completed.