Oracle PL/SQL Tutorial/SQL PLUS Session Environment/SQL PLUS Editor

To run statements in Oracle from the command line, a semicolon must be added.

From the editor, a slash (/) is added to execute the statement and no semicolon is used.

SQL> SELECT SUBSTR("My address is 123 Fourth St.",1,12)FROM dual
  2  /
SUBSTR("MYAD
------------
My address i
SQL>