How do I subtract using SQL in MYSQL between two date time values and retrieve the result in minutes or second?

I want to subtract between two date time values using SQL in MySQL such that I get the interval in minutes or seconds. Any ideas? I want to run a SQL query that retrieves uses from a database who have logged in like 10 minutes from the time.

There are functions TIMEDIFF(expr1,expr2), which returns the value of expr1-expr2, and TIME_TO_SEC(expr3), which expresses expr3 in seconds.

Note that expr1 and expr2 are datetime values, and expr3 is a time value only.

Check this link for more info.

TIMESTAMPDIFF is like TIMEDIFF which Matthew states, except it returns the difference of the two datetimes in whatever units you desire (seconds, minutes, hours, etc).

For example,

SELECT TIMESTAMPDIFF(MINUTE,LogOutTime,LogInTime) AS TimeLoggedIn
FROM LogTable

Would return the number of minutes the user was logged in (assuming you stored this kind of thing in a table like that).