The following is an example of a minimal PL/SQL block. It does nothing, but is syntactically correct. It starts with the BEGIN key word and ends with the END keyword.
Note that PL/SQL keywords are not case sensitive. The END and all executable statements must be followed by a semicolon.
At least one executable statement is required, either a PL/SQL statement or a SQL DML statement. In this case, NULL is the statement. The NULL statement simply passes control to the next statement. Since it takes no other action, it is useful for creating placeholders and stub subprograms.