drop table if exists t1;
CREATE TABLE t1 (
visitor_id int(10) unsigned DEFAULT '0' NOT NULL,
group_id int(10) unsigned DEFAULT '0' NOT NULL,
hits int(10) unsigned DEFAULT '0' NOT NULL,
sessions int(10) unsigned DEFAULT '0' NOT NULL,
ts timestamp(14),
PRIMARY KEY (visitor_id,group_id)
)/*! engine=MyISAM */;
INSERT INTO t1 VALUES (465931136,7,2,2,20000318160952);
INSERT INTO t1 VALUES (173865424,2,2,2,20000318233615);
INSERT INTO t1 VALUES (173865424,8,2,2,20000318233615);
INSERT INTO t1 VALUES (173865424,39,2,2,20000318233615);
INSERT INTO t1 VALUES (173865424,7,2,2,20000318233615);
INSERT INTO t1 VALUES (173865424,3,2,2,20000318233615);
INSERT INTO t1 VALUES (173865424,6,2,2,20000318233615);
INSERT INTO t1 VALUES (173865424,60,2,2,20000318233615);
INSERT INTO t1 VALUES (173865424,1502,2,2,20000318233615);
INSERT INTO t1 VALUES (48985536,2,2,2,20000319013932);
INSERT INTO t1 VALUES (48985536,8,2,2,20000319013932);
INSERT INTO t1 VALUES (48985536,39,2,2,20000319013932);
INSERT INTO t1 VALUES (48985536,7,2,2,20000319013932);
INSERT INTO t1 VALUES (465931136,3,2,2,20000318160951);
INSERT INTO t1 VALUES (465931136,119,1,1,20000318160953);
INSERT INTO t1 VALUES (465931136,2,1,1,20000318160950);
INSERT INTO t1 VALUES (465931136,8,1,1,20000318160950);
INSERT INTO t1 VALUES (465931136,39,1,1,20000318160950);
INSERT INTO t1 VALUES (1092858576,14,1,1,20000319013445);
INSERT INTO t1 VALUES (357917728,3,2,2,20000319145026);
INSERT INTO t1 VALUES (357917728,7,2,2,20000319145027);
select visitor_id,max(ts) as mts from t1 group by visitor_id
having mts < DATE_SUB(NOW(),INTERVAL 3 MONTH);
visitor_id	mts
48985536	2000-03-19 01:39:32
173865424	2000-03-18 23:36:15
357917728	2000-03-19 14:50:27
465931136	2000-03-18 16:09:53
1092858576	2000-03-19 01:34:45
select visitor_id,max(ts) as mts from t1 group by visitor_id
having DATE_ADD(mts,INTERVAL 3 MONTH) < NOW();
visitor_id	mts
48985536	2000-03-19 01:39:32
173865424	2000-03-18 23:36:15
357917728	2000-03-19 14:50:27
465931136	2000-03-18 16:09:53
1092858576	2000-03-19 01:34:45
drop table t1;