In MySQL, you can specify a column as auto_increment, the value will increment 1 at each insert. SQL Server also provide similar thing. Oracle using SEQUENCE and NEXTVAL to do the job.
Create a SEQUENCE:
Oracle provide PL/SQL packages let you extend the database functionality . You can write you own package or utilize the packages shipped with Oracle release.Oracle supplies all kinds of packages, familiar with these packages is a must-have skill of DBA.
Packages is a collection of different program objects include procedures, functions, variables, constants, cursors, exceptions etc.
Oracle released its 11g Database, it introduced a number of new features and improvement for PL/SQL.
A new built-in function REGEXP_COUNT available in PLSQL of Oracle11g. It match a regular expression pattern and return the number of matches. Here is an example: