Function to get business days

Question

hi
version oracle 10g
Function should accept start date and business_days_to_add and it should return date.
to a given date i want to add business_days(business days are all days except SAT SUN)
lets say i want to add 4 business days to sysdate then function should return date as 09/16/2010thanks

Answer 1

One way of doing it:
CREATE OR REPLACE FUNCTION add_business_days(p_date IN DATE, p_bus_days IN NUMBER) RETURN DATE DETERMINISTIC IS
  v_return DATE;
BEGIN
  WITH t AS
   (SELECT rownum rn, trunc(p_date) + decode(sign(p_bus_days), 1, LEVEL - 1, -1, (LEVEL * -1) + 1, 0) theday
      FROM dual
     WHERE to_char(p_date + decode(sign(p_bus_days), 1, LEVEL - 1
                                                   ,-1, (LEVEL * -1) + 1
                                                   , 0), 'DY', 'NLS_DATE_LANGUAGE=ENGLISH') NOT IN ('SAT', 'SUN')
           OR ROWNUM = 1
    CONNECT BY rownum <= abs(p_bus_days) + 1)
  SELECT theday
    INTO v_return
    FROM t
   WHERE rn = abs(p_bus_days) + 1;
  RETURN v_return;
END;Sample execution:
SQL> CREATE OR REPLACE FUNCTION add_business_days(p_date IN DATE, p_bus_days IN NUMBER) RETURN DATE DETERMINISTIC IS
  2    v_return DATE;
  3  BEGIN
  4    WITH t AS
  5     (SELECT rownum rn, trunc(p_date) + decode(sign(p_bus_days), 1, LEVEL - 1, -1, (LEVEL * -1) + 1, 0) theday
  6        FROM dual
  7       WHERE to_char(p_date + decode(sign(p_bus_days), 1, LEVEL - 1
  8                                                     ,-1, (LEVEL * -1) + 1
  9                                                     , 0), 'DY', 'NLS_DATE_LANGUAGE=ENGLISH') NOT IN ('SAT', 'SUN')
10             OR ROWNUM = 1
11      CONNECT BY rownum <= abs(p_bus_days) + 1)
12    SELECT theday
13      INTO v_return
14      FROM t
15     WHERE rn = abs(p_bus_days) + 1;
16    RETURN v_return;
17  END;
18  /
Function created
SQL> select add_business_days(sysdate, 5) from dual;
ADD_BUSINESS_DAYS(SYSDATE,5)
17/9/2010
SQL> select add_business_days(sysdate, -55) from dual;
ADD_BUSINESS_DAYS(SYSDATE,-55)
25/6/2010
SQL> select add_business_days(sysdate+1, 1) from dual;
ADD_BUSINESS_DAYS(SYSDATE+1,1)
13/9/2010
SQL> select add_business_days(sysdate+1, -1) from dual;
ADD_BUSINESS_DAYS(SYSDATE+1,-1
10/9/2010
SQL> Edited by: fsitja on Sep 10, 2010 12:49 PM Fixed to take into account negative numbers.