I am trying to filter my db for parts that have not been updated within the last 30 minutes, but cannot see to get the syntax right, comments?

SELECT *
FROM tbl_material
WHERE date_stamp<= now()-30
AND module_id =1902
AND part = "1142226"
AND factory = "3862"

in what database syntax?

mySQL

I am still working it and this is what I got so far but still no joy

SELECT * FROM tbl_material WHERE
DATEDIFF(date_stamp,now())<1800
module_id='1902' AND
part="1142226" AND
factory="3862"

Just realized that I was missing the AND but still not a happy camper.

How does the datediff handle date? Am I camparing the value correctly?

SELECT *
FROM tbl_material
WHERE DATEDIFF( date_stamp, now( ) ) <30
AND module_id = '1902'
AND part = "1142226"
AND factory = "3862"

DATESUB is the function to use

Thanks for the help Chrishirst.

Here is the final solution

SELECT *
FROM tbl_material
WHERE module_id = '1902'
AND part = "1142226"
AND factory = "3862"
AND date_stamp <= DATE_SUB( now( ) , INTERVAL 30
MINUTE )
LIMIT 0 , 30