Add days Oracle SQL

Question

SELECT ORDER_NUM, CUSTOMER_NUM, CUSTOMER_NAME, ADD_DAYS (ORDER_DATE, 20)
FROM CUSTOMER, ORDERS; 

Oracle Express says ADD_DAYS invalid? Any ideas wh

Answer 1

Some disadvantage of "INTERVAL '1' DAY" is that bind variables cannot be used for the number of days added. Instead, numtodsinterval can be used, like in this small example:

select trunc(sysdate) + numtodsinterval(:x, 'day') tag
from dual

See also: NUMTODSINTERVAL in Oracle Database Online Documentation