; WITH valid_positions AS (
SELECT MMSI
, Message_ID
, "Time"
, Latitude
, Longitude
FROM dbo.DecodedCSVMessages_Staging
WHERE Latitude > 55
AND Latitude < 85
AND Longitude > 50
AND Longitude < 141
)
, positions AS (
SELECT MMSI
, Message_ID
, "Time"
, Latitude
, Longitude
FROM dbo.DecodedCSVMessages_Staging
WHERE Message_ID IN (1, 3)
AND EXISTS (
SELECT *
FROM valid_positions
WHERE valid_positions.MMSI = DecodedCSVMessages_Staging.MMSI
)
)
, details AS (
SELECT MMSI
, Ship_Type
, Vessel_Name
, Row_Number() OVER (PARTITION BY MMSI ORDER BY "Time" DESC) As row_num
FROM dbo.DecodedCSVMessages_Staging
WHERE Message_ID = 5
)
SELECT positions.MMSI
, positions.Message_ID
, positions."Time"
, details.Ship_Type
, details.Vessel_Name
, positions.Latitude
, positions.Longitude
FROM positions
INNER
JOIN details
ON details.MMSI = positions.MMSI
AND details.row_num = 1 -- Limit to "latest" ship details per MMSI
Ora è in uso un 3° CTE.
valid_positions
:qualsiasi record in cui le coordinate corrispondono ai tuoi criteri, per qualsiasiMessage_ID
2)positions
:tutti i record in cuiMessage_ID
è uguale a 1 o 3 e c'è un record nel corrispondenteMMSI
invalid_positions
details
:invariato rispetto a prima. Mostra i dettagli "più recenti" della nave/nave (Message_ID
=5)