我有一个包含设备gps坐标的sql表，每隔 n 分钟更新一次（设备安装在车辆中）。鉴于GPS的性质，许多条目非常相似，但就服务器而言则完全不同。我可以使用CAST(lat as decimal(7,4))
我希望能够获取结果集并压缩大致重复的条目，但仍然保持基于时间的顺序。这是一个例子：
Row Lat Lng vel Hdg Time
01 31.12345 -88.12345 00 00 12-4-21 01:45:00
02 31.12346 -88.12345 00 00 12-4-21 01:46:00
03 31.12455 -88.12410 10 01 12-4-21 01:47:00
04 31.12495 -88.12480 17 01 12-4-21 01:48:00
05 31.12532 -88.12560 22 01 12-4-21 01:49:00
06 31.12567 -88.12608 25 02 12-4-21 01:50:00
07 31.12638 -88.12672 24 02 12-4-21 01:51:00
08 31.12689 -88.12722 19 02 12-4-21 01:52:00
09 31.12345 -88.12345 00 00 12-4-21 01:53:00
10 31.12346 -88.12346 00 00 12-4-21 01:54:00
11 31.12347 -88.12345 00 00 12-4-21 01:55:00
12 31.12346 -88.12346 00 00 12-4-21 01:56:00
13 31.12689 -88.12788 10 40 12-4-21 01:57:00
14 31.12604 -88.12691 13 39 12-4-21 01:58:00
15 31.12572 -88.12603 15 39 12-4-21 01:59:00
我想要的最终结果是将第1行和第2行压缩为单行，第9行到第12行压缩为一行，包含AVG(Lat)，AVG(Lng)和{{1 }}
鉴于上述数据，这是我想收到的结果集：
MIN(Time)分组之间的界限将是运动。速度> 0或gps坐标变化超过 x 数量。在这种情况下， x 是.0001。如下所述，问题是将给定坐标处的多个停靠点（AT不同时间点）集中到一个停靠点中。如果我今天下午4点，明天早上8点，然后又是下午6点访问坐标x ，我看到的唯一一个是明天@ 6 pm（在{{1}的情况下） }）或今天@ 4 pm（在Row Lat Lng vel Hdg Time
01 31.123455 -88.12345 00 00 12-4-21 01:45:00
02 31.12455 -88.12410 10 01 12-4-21 01:47:00
03 31.12495 -88.12480 17 01 12-4-21 01:48:00
04 31.12532 -88.12560 22 01 12-4-21 01:49:00
05 31.12567 -88.12608 25 02 12-4-21 01:50:00
06 31.12638 -88.12672 24 02 12-4-21 01:51:00
07 31.12689 -88.12722 19 02 12-4-21 01:52:00
08 31.12346 -88.123455 00 00 12-4-21 01:53:00
09 31.12689 -88.12788 10 40 12-4-21 01:57:00
10 31.12604 -88.12691 13 39 12-4-21 01:58:00
11 31.12572 -88.12603 15 39 12-4-21 01:59:00
的情况下）。
如果速度为0，则航向也为0.但是，如果行1和2以及9到12的坐标相似且足够相同（即四舍五入到小数点后4位。）
我有一个查询就是这样：
MAX(Time)换句话说，如果我从A点旅行到B点，请停留30分钟（30分钟，每分钟1次），然后前往C点，停留20分钟，然后返回B点并停留在前往D点前20分钟，我希望能够在B点看到两个单独的站点。
这是我的数据库中的一些实际数据，为保护无辜者而进行了消毒，或者在阿拉巴马州东北部责怪某人。
MIN(Time)你会注意到第4行和最后一行分别有527和168个条目，它们跨越2天。这些条目仅来自1个设备，并且是设备在多个场合多次在同一地点停止的地方。
以下是一些压缩的csv数据：sample
对Aaron Bertrand提供的查询进行了一些小修改，如下所示：
SELECT Geography::Point(AVG(dbo.GPSEntries.Latitude),
AVG(dbo.GPSEntries.Longitude),
4326 ) as Location,
dbo.GPSEntries.Velocity,
dbo.GPSEntries.Heading,
MAX(dbo.GPSEntries.Time) as maxTime,
MIN(dbo.GPSEntries.Time) as minTime,
AVG(dbo.RFDatas.RSSI) as avgRSSI,
COUNT(1) as samples
FROM dbo.GPSEntries
INNER JOIN
dbo.Reports ON
dbo.GPSEntries.Report_Id = dbo.Reports.Id
INNER JOIN
dbo.RFDatas ON
dbo.GPSEntries.Report_Id = dbo.RFDatas.Report_Id
GROUP BY CAST(Latitude as Decimal(7,4)),
CAST(Longitude as Decimal(7,4)),
Velocity,
Heading
ORDER BY MAX(Time)
答案 0 :(得分：1)
以下是tempdb中的一些示例数据：
USE tempdb;
GO
CREATE TABLE dbo.GPSEntries
(
Latitude DECIMAL(8,5),
Longitude DECIMAL(8,5),
Velocity TINYINT,
Heading TINYINT,
[Time] SMALLDATETIME
);
INSERT dbo.GPSEntries VALUES
(31.12345,-88.12345,00,00,'2012-04-21 01:45:00'),
(31.12346,-88.12345,00,00,'2012-04-21 01:46:00'),
(31.12455,-88.12410,10,01,'2012-04-21 01:47:00'),
(31.12495,-88.12480,17,01,'2012-04-21 01:48:00'),
(31.12532,-88.12560,22,01,'2012-04-21 01:49:00'),
(31.12567,-88.12608,25,02,'2012-04-21 01:50:00'),
(31.12638,-88.12672,24,02,'2012-04-21 01:51:00'),
(31.12689,-88.12722,19,02,'2012-04-21 01:52:00'),
(31.12345,-88.12345,00,00,'2012-04-21 01:53:00'),
(31.12346,-88.12346,00,00,'2012-04-21 01:54:00'),
(31.12347,-88.12345,00,00,'2012-04-21 01:55:00'),
(31.12346,-88.12346,00,00,'2012-04-21 01:56:00'),
(31.12689,-88.12788,10,40,'2012-04-21 01:57:00'),
(31.12604,-88.12691,13,39,'2012-04-21 01:58:00'),
(31.12572,-88.12603,15,39,'2012-04-21 01:59:00');
我尝试满足查询：
;WITH d AS
(
SELECT Time, Latitude, Longitude, Velocity, Heading,
NormLat = CONVERT(DECIMAL(7,4), Latitude),
NormLong = CONVERT(DECIMAL(7,4), Longitude),
TimeRN = ROW_NUMBER() OVER (ORDER BY [Time])
FROM dbo.GPSEntries
-- /* you probably want filters:
-- WHERE DeviceID = @SomeDeviceID
-- AND [Time] >= @SomeStartDate
-- AND [Time] < DATEADD(DAY, 1, @SomeEndDate)
-- /* also your sample CSV file had lots of duplicates, so:
GROUP BY Time, Latitude, Longitude, Velocity, Heading
),
y AS (
SELECT MinTime = MIN(Time), MaxTime = MAX(Time), Latitude = AVG(Latitude),
Longitude = AVG(Longitude), [RowCount] = COUNT(*) FROM
(
SELECT Time, Latitude, Longitude, GroupNumber =
(
SELECT MIN(d2.TimeRN)
FROM d AS d2 WHERE d2.TimeRN >= d.TimeRN
AND NOT EXISTS
(
SELECT 1 FROM d AS d3
WHERE d2.NormLat = d.NormLat
AND d2.NormLong = d.NormLong
)
)
FROM d
) AS x GROUP BY GroupNumber
)
SELECT [Row] = ROW_NUMBER() OVER (ORDER BY y.MinTime),
y.Latitude, y.Longitude, d.Velocity, d.Heading,
y.MinTime, y.MaxTime, y.[RowCount]
FROM y INNER JOIN d ON y.MinTime = d.[Time]
ORDER BY y.MinTime;
结果：
Row Latitude Longitude Velocity Heading MinTime MaxTime RowCount
---|---------|----------|--------|-------|----------------|----------------|--------
1 31.123455 -88.123450 0 0 2012-04-21 01:45 2012-04-21 01:46 2
2 31.124550 -88.124100 10 1 2012-04-21 01:47 2012-04-21 01:47 1
3 31.124950 -88.124800 17 1 2012-04-21 01:48 2012-04-21 01:48 1
4 31.125320 -88.125600 22 1 2012-04-21 01:49 2012-04-21 01:49 1
5 31.125670 -88.126080 25 2 2012-04-21 01:50 2012-04-21 01:50 1
6 31.126380 -88.126720 24 2 2012-04-21 01:51 2012-04-21 01:51 1
7 31.126890 -88.127220 19 2 2012-04-21 01:52 2012-04-21 01:52 1
8 31.123460 -88.123455 0 0 2012-04-21 01:53 2012-04-21 01:56 4
9 31.126890 -88.127880 10 40 2012-04-21 01:57 2012-04-21 01:57 1
10 31.126040 -88.126910 13 39 2012-04-21 01:58 2012-04-21 01:58 1
11 31.125720 -88.126030 15 39 2012-04-21 01:59 2012-04-21 01:59 1