When do I need to use a semicolon vs a slash in Oracle SQL?

Question

We have been having some debate this week at my company as to how we should write our SQL scripts.

Background: Our database is Oracle 10g (upgrading to 11 soon).

Answer 1

Almost all Oracle deployments are done through SQL*Plus (that weird little command line tool that your DBA uses). And in SQL*Plus a lone slash basically means "re-execute last SQL or PL/SQL command that I just executed".

See

http://ss64.com/ora/syntax-sqlplus.html

Rule of thumb would be to use slash with things that do BEGIN .. END or where you can use CREATE OR REPLACE.

For inserts that need to be unique use

INSERT INTO my_table ()
SELECT 
FROM dual
WHERE NOT EXISTS (SELECT 
                  FROM my_table
                  WHERE )