Jumlahkan durasi waktu berdasarkan perubahan lokasi

Berikut ini tampaknya berhasil:

SET @locationID=0,@ts=NULL,@changed=0;

SELECT
  MIN(assetID) AS id
  , MIN(locationID) AS location
  , SUM(secDiff) AS duration
FROM
  (SELECT
    assetID
    , locationID
    , @changed := IF(locationID <> previousLocationID, @changed + 1, @changed) AS changed
    , IFNULL(TIMESTAMPDIFF(SECOND,
                           previousTs,
                           ts
                           ),
             0
      ) AS secDiff
  FROM
    (SELECT
      assetID
      , locationID
      , @locationID AS previousLocationID
      , @locationID := locationID AS currentLocationID
      , ts
      , @ts AS previousTs
      , @ts := ts AS currentTs
    FROM Logs L1
    WHERE assetid = 1157    
    ORDER BY ts
    ) L2
  ORDER BY ts
  ) L3
GROUP BY changed
ORDER BY changed DESC
;

Lihat aksinya:SQL Fiddle .

Pembaruan:

Jika Anda perlu bergabung dengan tabel tambahan, Anda harus benar-benar JOIN dan bukan sub-pilih. Karena ada GROUP BY pada level terluar saat ini, pernyataan yang ada perlu dibungkus dengan tanda kurung lain - untuk mencegah pengelompokan tabel fakta. Dengan beberapa penyesuaian lain untuk tujuan itu:

SET @locationID=0,@ts=NULL,@changed=0;

SELECT
  A.name
  , L4.assetID
  , L.name
  , L4.locationID
  , duration
FROM
  (SELECT
    MIN(assetID) AS assetID
    , MIN(locationID) AS locationID
    , SUM(secDiff) AS duration
    , changed
  FROM
    (
-- no change in here
    ) L3
  GROUP BY changed
  ) L4
JOIN Asset A
  ON L4.assetID = A.id
JOIN Location L
  ON L4.locationID = L.id
ORDER BY changed DESC
;

Memperluas SQL Fiddle .

Pembaruan 2:

Cara paling mudah untuk mengatasi cantuman duplikat adalah dengan DISTINCT mereka pergi sebagai langkah pertama:

-- no change here
  (SELECT
    assetID
    , locationID
    , @locationID AS previousLocationID
    , @locationID := locationID AS currentLocationID
    , ts
    , @ts AS previousTs
    , @ts := ts AS currentTs
  FROM
    (SELECT DISTINCT
      assetID
      , locationID
      , ts
    FROM Logs
    WHERE assetid = 1157
    ) L1
  ORDER BY ts
  ) L2
-- no change here either

SQL Fiddle ini pengembalian untuk Log . yang digandakan data hasil yang sama ditetapkan sebagai SQL Fiddle , di mana kueri sebelumnya dijalankan terhadap data tanpa duplikat.

Silakan berkomentar, jika dan karena ini memerlukan penyesuaian / detail lebih lanjut.