gaps-and-islands

I've got an events table that is generated by user activity on a site: timestamp | name 7:00 AM | ... 7:01 AM | ... 7:02 AM | ... 7:30 AM | ... 7:31 AM | ... 7:32 AM | ... 8:01 AM | ... 8:03 AM | ... 8:05 AM | ... 8:08 AM | ... 8:09 AM | ... I'd like to aggregate over the events to provide a view of when a user is active. I'm defining active to mean the period in which an event is within +/- 2 minutes. For the above that'd mean: from | till 7:00 AM | 7:02 AM 7:30 AM | 7:32 AM 8:01 AM | 8:05 AM 8:08 AM | 8:09 AM What's the best way to write a query that'll aggregate in that method? Is it

I want to set the doprocess flag to 0 if the below data is empty between any of the targets mentioned Example: create table TestSAMP ( id int identity(1,1), modelid navrchar(max), target1 nvarchar(max), target2 nvarchar(max), target3 nvarchar(max), target4 nvarchar(max), doprcoess int default(1) ) --VALID SET DOPROCESS FLAG TO 1 INSERT INTO TestSAMP(modelid,target1,target2,target3,target4) VALUES('1','T1','T2','T3','T4') --NOTVALID SET DOPROCESS FLAG TO 0 DUE TO THE DATA IS MISSING IN SEQUENCE INSERT INTO TestSAMP(modelid,target1,target2,target3,target4) VALUES('2','TR','','T3','T4') --VALID

Hello I'm using this sql query to get the last 12 month records based on month for chart representation: SELECT DATE_FORMAT(drives.timestamp, "%b") AS Month, DATE_FORMAT(drives.timestamp, "%d-%m-%Y %H:%i:%s") AS Exact_date, drives.departure, drives.destination, drives.route, CONCAT(drivers.name, " ", drivers.surname) as driver, drivers.id as driver_id FROM drives, drivers WHERE drives.driver = drivers.id AND drives.timestamp > DATE_SUB(now(), INTERVAL 12 MONTH) ORDER BY drives.timestamp Asc however if there are no records for a month it is not included in the result set as expected, and I'm

Finding the start and end time for adjacent records that have the same value? I have a table that contains heart rate readings (in beats per minute) and datetime field. (Actually the fields are heartrate_id , heartrate , and datetime .) The data are generated by a device that records the heart rate and time every 6 seconds. Sometimes the heart rate monitor will give false readings and the recorded beats per minute will "stick" for an period of time. By sticks, I mean the beats per minute value will be identical in adjacent times. Basically I need to find all the records where the heart rate is

How can I check if a range is completely covered by a set of ranges. In the following example: WITH ranges(id, a, b) AS ( SELECT 1, 0, 40 UNION SELECT 2, 40, 60 UNION SELECT 3, 80, 100 UNION SELECT 4, 10, 30 ), tests(id, a, b) AS ( SELECT 1, 10, 90 UNION SELECT 2, 10, 60 ) SELECT * FROM tests WHERE -- ? I want to select 10, 60 because all of it is covered by 0, 40 and 40, 60 (and 10, 30 ) I want to exclude 10, 90 because it is exposed between 60, 80 Assume that a is inclusive and b is exclusive i.e. the value 40 belongs to [40, 60) and not [0, 40) . The ranges can contain gaps and all kind of

I'm trying to figure out a way of identifying a "run" of results (successive rows, in order) that meet some condition. Currently, I'm ordering a result set, and scanning by eye for particular patterns. Here's an example: SELECT the_date, name FROM orders WHERE the_date BETWEEN to_date('2013-09-18',..) AND to_date('2013-09-22', ..) ORDER BY the_date -------------------------------------- the_date | name -------------------------------------- 2013-09-18 00:00:01 | John -------------------------------------- 2013-09-19 00:00:01 | James -------------------------------------- 2013-09-20 00:00:01 |

Possible Duplicate: MySQL how to fill missing dates in range? I'm trying to make a graph from mysqldata, Postid | date | text 1 | 2012-01-01 | bla 2 | 2012-01-01 | bla 3 | 2012-01-02 | bla 4 | 2012-01-02 | bla 5 | 2012-01-04 | bla 6 | 2012-01-04 | bla 7 | 2012-01-05 | bla Now, I'd like to get the number of posts on every day, INCLUDING dates with zero. For example, i'd like to be able to get the first week like this: date | count(Postid) 2012-01-01 | 2 2012-01-02 | 2 2012-01-03 | 0 2012-01-04 | 2 2012-01-05 | 1 2012-01-06 | 0 2012-01-07 | 0 I'm looking for a generic solution, where i don't