ADD MONTHS in DB2

In IBM DB2, you can use the MONTHS_BETWEEN() function to calculate the difference in months between two dates and then add or subtract the desired number of months accordingly. Here's how you can achieve this:

Suppose you have a table named orders with a column order_date of type DATE. To add or subtract months from the order_date, you can use the following approach:

SELECT

    ORDER_DATE,

    ORDER_DATE + (NUMBER_OF_MONTHS || ' MONTHS') AS NEW_ORDER_DATE

FROM

    ORDERS;

In this query:

- We use the + operator to add the calculated number of months to the ORDER_DATE.

- The NUMBER_OF_MONTHS || ' MONTHS' concatenates the number of months with the string ' MONTHS'. This forms the interval expression required by DB2 to add or subtract months.

- Replace NUMBER_OF_MONTHS with the actual number of months you want to add or subtract. If you want to subtract months, you can use a negative value.

For example, to add 3 months to the ORDER_DATE, the query would be:

SELECT

    ORDER_DATE,

    ORDER_DATE + (3 || ' MONTHS') AS NEW_ORDER_DATE

FROM

    ORDERS;

And to subtract 6 months from the ORDER_DATE, the query would be:

SELECT

    ORDER_DATE,

    ORDER_DATE + (-6 || ' MONTHS') AS NEW_ORDER_DATE

FROM

    ORDERS;

This will give you the ORDER_DATE with the specified number of months added or subtracted in the NEW_ORDER_DATE column.