SQL query for getting data for last 3 months

How can you get today's date and convert it to 01/mm /yyyy format and get data from the table with delivery month 3 months ago? Table already contains delivery month as 01/mm/yyyy.

SELECT * 
FROM TABLE_NAME
WHERE Date_Column >= DATEADD(MONTH, -3, GETDATE()) 

Mureinik's suggested method will return the same results, but doing it this way your query can benefit from any indexes on Date_Column.

or you can check against last 90 days.

SELECT * 
FROM TABLE_NAME
WHERE Date_Column >= DATEADD(DAY, -90, GETDATE()) 

Latest Versions of mysql don't support DATEADD instead use the syntax

DATE_ADD(date,INTERVAL expr type)

To get the last 3 months data use,

DATE_ADD(NOW(),INTERVAL -90 DAY) 
DATE_ADD(NOW(), INTERVAL -3 MONTH)