PIVOT data in mysql - mysql

Question

RCDID, EmployeeID, LogDate, LogTime, TerminalID, InOut, read
3079184, 'A00075', '2009/10/28', '07:17:10 ', 'VC01 ', 'IN ', '1'
3079185, 'A00075', '2009/10/28', '17:28:51 ', 'VC01 ', 'OUT ', '1'
3079186, 'A00038', '2009/10/28', '07:29:17 ', 'VC01 ', 'IN ', '1'
3079187, 'A00038', '2009/10/28', '17:30:05 ', 'VC01 ', 'OUT ', '1'
3079188, 'A00085', '2009/10/28', '07:37:34 ', 'VC01 ', 'IN ', '1'
3079189, 'A00085', '2009/10/28', '17:43:14 ', 'VC01 ', 'IN ', '1'
Hi, above is my source table (mysql) i want to cross tab the data as follows.
EmployeeID, LogDate, In_location, in_time, Out_location, Out_time
'A00001', '2009/10/28', 'VC01', '08:37:55 ', '', '',
'A00001', '2009/10/29', 'VC01', '08:09:57 ', 'VC01 ', '17:09:32 '
'A00001', '2009/10/30', 'VC01 ', '09:48:41 ', 'VC01 ', '20:40:37 '
'A00001', '2009/11/03', 'VC01', '08:20:34 ', 'VC01 ', '18:03:34 '
'A00001', '2009/11/04', 'VC01 ', '08:26:49 ', 'VC01 ', '19:21:46 '
'A00001', '2009/11/05', 'VC01', '08:16:00 ', 'VC01 ', '19:26:01 '
can somebody help me please. i am really appreciate your help

Answer 1

Essentially, one needs to perform a self-join to pair up movements IN with the following OUT by the same employee on the same date:
SELECT a.EmployeeID, a.LogDate,
a.LogTime AS In_time,
MIN(b.LogTime) AS Out_time
FROM my_table a LEFT JOIN my_table b ON
a.EmployeeID = b.EmployeeID
AND a.LogDate = b.LogDate
AND a.LogTime < b.LogTime
AND b.InOut = 'OUT'
WHERE a.InOut = 'IN'
GROUP BY EmployeeID, LogDate, In_time
However, this excludes situations where there is an IN record with no corresponding OUT record. Since MySQL has no native support for FULL OUTER JOIN, one must instead use UNION to combine the above with a similar query that pairs movements OUT with the preceding IN by the same employee on the same date:
SELECT a.EmployeeID, a.LogDate,
a.LogTime AS In_time,
MIN(b.LogTime) AS Out_time
FROM my_table a LEFT JOIN my_table b ON
a.EmployeeID = b.EmployeeID
AND a.LogDate = b.LogDate
AND a.LogTime < b.LogTime
AND b.InOut = 'OUT'
WHERE a.InOut = 'IN'
GROUP BY EmployeeID, LogDate, In_time
UNION
SELECT a.EmployeeID, a.LogDate,
MAX(a.LogTime) AS In_time,
b.LogTime AS Out_time
FROM my_table a RIGHT JOIN my_table b ON
a.EmployeeID = b.EmployeeID
AND a.LogDate = b.LogDate
AND a.LogTime < b.LogTime
AND a.InOut = 'IN'
WHERE b.InOut = 'OUT'
GROUP BY EmployeeID, LogDate, Out_time
Having obtained this detail, one then needs to join the result with the table again in order to extract the terminals on which the movements were logged:
SELECT t.EmployeeID,
t.LogDate,
a.TerminalID AS In_location,
t.In_time,
b.TerminalID AS Out_location,
t.Out_time
FROM (
SELECT a.EmployeeID, a.LogDate,
a.LogTime AS In_time,
MIN(b.LogTime) AS Out_time
FROM my_table a LEFT JOIN my_table b ON
a.EmployeeID = b.EmployeeID
AND a.LogDate = b.LogDate
AND a.LogTime < b.LogTime
AND b.InOut = 'OUT'
WHERE a.InOut = 'IN'
GROUP BY EmployeeID, LogDate, In_time
UNION
SELECT a.EmployeeID, a.LogDate,
MAX(a.LogTime) AS In_time,
b.LogTime AS Out_time
FROM my_table a RIGHT JOIN my_table b ON
a.EmployeeID = b.EmployeeID
AND a.LogDate = b.LogDate
AND a.LogTime < b.LogTime
AND a.InOut = 'IN'
WHERE b.InOut = 'OUT'
GROUP BY EmployeeID, LogDate, Out_time
) t
LEFT JOIN my_table a ON
a.EmployeeID = t.EmployeeID
AND a.LogDate = t.LogDate
AND a.LogTime = t.In_time
AND a.InOut = 'IN'
LEFT JOIN my_table b ON
b.EmployeeID = t.EmployeeID
AND b.LogDate = t.LogDate
AND b.LogTime = t.Out_time
AND b.InOut = 'OUT'
See it on sqlfiddle.