Nested Blocks in PL/SQL in Oracle

A block may also contain nested sub−blocks of code. The following example shows a procedure with an anonymous, nested block defined within it:

PROCEDURE calc_totals IS
year_total NUMBER;
BEGIN
year_total := 0;
/* Nested anonymous block */
DECLARE
month_total NUMBER;
BEGIN
month_total := year_total / 12;
END;
END;


Notice that I can reference the year_total variable inside the nested block. Any element declared in an outer
block is global to all blocks nested within it. Any element declared within an inner block cannot, however, be
referenced in an outer block.