Use a nested block to catch exceptions from singleton SELECT. : Handle Exception « PL SQL Programming « Oracle PL/SQL Tutorial






SQL> CREATE TABLE good_for (
  2     product_id NUMBER,
  3     good_for INTERVAL YEAR(2) TO MONTH NOT NULL
  4  );

Table created.

SQL>
SQL> CREATE OR REPLACE FUNCTION get_expiration (p_product_id NUMBER)
  2     RETURN DATE
  3  AS
  4     v_good_for good_for.good_for%type;
  5     expiration_date DATE;
  6     found_flag BOOLEAN;
  7  BEGIN
  8    BEGIN
  9      SELECT gf.good_for INTO v_good_for
 10      FROM good_for gf
 11      WHERE gf.product_id = p_product_id;
 12      found_flag := TRUE;
 13    EXCEPTION
 14       WHEN OTHERS THEN
 15         found_flag := FALSE;
 16    END;
 17    IF found_flag THEN
 18      expiration_date := TRUNC(SYSDATE) + v_good_for;
 19    ELSE
 20      expiration_date := null;
 21    END IF;
 22
 23    RETURN expiration_date;
 24  END;
 25  /

Function created.

SQL>
SQL> INSERT INTO good_for (product_id, good_for)
  2     VALUES (1, INTERVAL '1-4' YEAR TO MONTH);

1 row created.

SQL>
SQL> SELECT get_expiration(1) FROM DUAL;

GET_EXPIR
---------
24-NOV-09

SQL>
SQL>
SQL> drop table good_for;

Table dropped.

SQL>
SQL>








24.15.Handle Exception
24.15.1.Code with No Exception Handler
24.15.2.Code with Conditional Control to Avoid an Exception
24.15.3.Code with Explicit Handler for Predefined Exception
24.15.4.Handling an Unnamed Exception
24.15.5.Handling a custom exception
24.15.6.An example showing continuing program execution after handling exception
24.15.7.The OTHERS Exception Handler
24.15.8.Assigning a Name to Predefined Exception Code
24.15.9.Using SQLCODE for error code and SQLERRM for error message
24.15.10.Catch custom exception
24.15.11.Handling exceptions without halting the program
24.15.12.Select into statement with exception catch statement
24.15.13.Check OTHERS exception
24.15.14.Error message code and text
24.15.15.Using PRAGMA EXCEPTION_INIT
24.15.16.NO data found
24.15.17.TOO_MANY_ROWS Exception
24.15.18.Use a nested block to catch exceptions from singleton SELECT.