Grouping records with time

[son.of.the.morning]

Anyone have any idear how i would group records by time. For example if the timestamp of the record is in less 30mins affter the pervious record then group it with that record and so on and so forth. Facebook use somthing similar....

 

"John likes HotBabes, SexyBitches and four other pages"

[Barand]

SELECT FLOOR(UNIX_TIMESAMP(timestamp) / 1800) as timegroup, ....

[son.of.the.morning]

Tryied to do a lil google search on it and couldnt find much.

 

 

						SELECT * FROM results, actions, commitment_users AS commitment_member, commitment_users AS commitment_admin, users AS admin,users AS member, commitments
						WHERE commitment_admin.user_id = admin.id
							AND
						admin.id = 1
							AND
						commitment_admin.commitment_user_type_id IN(2,3)
							AND		
                            commitment_admin.commitment_id = commitment_member.commitment_id
					        AND
						commitment_member.commitment_id = commitments.id
							AND
						commitment_member.commitment_user_type_id IN (1,2) 
							AND
						actions.commitment_id = commitments.id
							AND
						results.action_id = actions.id
							AND
						results.user_id = member.id

						GROUP BY results.id
						ORDER BY results.date_created, results.time

 

Here is my query at current