SQLLite time entry and time exit from eventime

Question

I have two tables, DATA and EVENTS, with the following data:

EVENTS
EventIndex  ObjID   LocID   EventData   EventTime       EventType
8         


        

Answer 1

Something like this could get you started along nicely:

SQL Fiddle: http://www.sqlfiddle.com/#!2/6e6a7/33

SELECT d.TagValue AS Name,
       d2.TagValue AS LOCATION,
       e.eventTime AS Entry,

  ( SELECT eventtime
   FROM EVENTS e2
   WHERE e2.objID = e.objID
     AND e2.eventTime > e.eventTime LIMIT 1) AS ExitTime,
       (e.eventTime -
          ( SELECT eventtime
           FROM EVENTS e2
           WHERE e2.objID = e.objID
             AND e2.eventTime > e.eventTime LIMIT 1)) AS TotalTime
FROM events e,
     DATA d,
          DATA d2
WHERE e.eventIndex = d.eventIndex
  AND e.eventIndex = d2.eventIndex
  AND d.TagName = "ObjName"
  AND d2.TagName = "LocName"
  AND mod(
            ( SELECT count(*)
             FROM EVENTS e2
             WHERE e2.objID = e.objID
               AND e2.eventTime < e.eventTime),2) = 0
ORDER BY EventTime;

Result:

NAME    LOCATION    ENTRY                   EXITTIME                  TOTALTIME
John    H118    May, 19 2013 11:32:11+0000  May, 19 2013 11:35:18+0000  -307
Peter   H118    May, 19 2013 12:24:45+0000  May, 19 2013 12:32:18+0000  -773

I added extra events, to proof against an exit from one event being considered as an entry of another.

The above query can be optimized, if we say that an entry and exit cannot take place on different days e.g. USER enters 11.59PM and leaves 1.00AM...

SELECT d.TagValue AS Name,
       d2.TagValue AS LOCATION,
       e.eventTime AS Entry,

  ( SELECT eventtime
   FROM EVENTS e2
   WHERE e2.objID = e.objID
     AND e2.eventTime > e.eventTime LIMIT 1) AS ExitTime,
       (e.eventTime -
          ( SELECT eventtime
           FROM EVENTS e2
           WHERE e2.objID = e.objID
             AND e2.eventTime > e.eventTime AND
             DATE(e2.eventTime) = DATE(e.eventTime) LIMIT 1)) AS TotalTime
FROM events e,
     DATA d,
          DATA d2
WHERE e.eventIndex = d.eventIndex
  AND e.eventIndex = d2.eventIndex
  AND d.TagName = "ObjName"
  AND d2.TagName = "LocName"
  AND mod(
            ( SELECT count(*)
             FROM EVENTS e2
             WHERE e2.objID = e.objID
               AND e2.eventTime < e.eventTime AND
               DATE(e2.eventTime) = DATE(e.eventTime)),2) = 0
ORDER BY EventTime;

SQL Fiddle: http://www.sqlfiddle.com/#!2/6e6a7/35

This also assumes that each entry must have an exit, which is why I use the modulo operator. All Even events for a Object are an entry, all Odd events are an exit.

For more conditions, obviously the query must be modified.

Update: Using SQL Lite (no mod but %)

SQLFiddle: http://www.sqlfiddle.com/#!7/6e6a7/4

SELECT d.TagValue AS Name,
       d2.TagValue AS LOCATION,
       e.eventTime AS Entry,

  ( SELECT eventtime
   FROM EVENTS e2
   WHERE e2.objID = e.objID
     AND e2.eventTime > e.eventTime LIMIT 1) AS ExitTime,
       (e.eventTime -
          ( SELECT eventtime
           FROM EVENTS e2
           WHERE e2.objID = e.objID
             AND e2.eventTime > e.eventTime LIMIT 1)) AS TotalTime
FROM events e,
     DATA d,
          DATA d2
WHERE e.eventIndex = d.eventIndex
  AND e.eventIndex = d2.eventIndex
  AND d.TagName = "ObjName"
  AND d2.TagName = "LocName"
  AND (
            ( SELECT count(*)
             FROM EVENTS e2
             WHERE e2.objID = e.objID
               AND e2.eventTime < e.eventTime)%2) = 0
ORDER BY EventTime;