我当前的数据
final FirebaseAuth firebaseAuth = FirebaseAuth.instance;
final GoogleSignIn _googleSignIn = new GoogleSignIn();
void initState(){
super.initState();
firebaseAuth.onAuthStateChanged
.firstWhere((user) => user != null)
.then((user) {
String user_Name = user.displayName;
String image_Url = user.photoUrl;
String email_Id = user.email;
String user_Uuid = user.uid; // etc
}
// Give the navigation animations, etc, some time to finish
new Future.delayed(new Duration(seconds: 2))
.then((_) => signInWithGoogle());
}
Future<FirebaseUser> signInWithGoogle() async {
// Attempt to get the currently authenticated user
GoogleSignInAccount currentUser = _googleSignIn.currentUser;
if (currentUser == null) {
// Attempt to sign in without user interaction
currentUser = await _googleSignIn.signInSilently();
}
if (currentUser == null) {
// Force the user to interactively sign in
currentUser = await _googleSignIn.signIn();
}
final GoogleSignInAuthentication googleAuth =
await currentUser.authentication;
// Authenticate with firebase
final FirebaseUser user = await firebaseAuth.signInWithGoogle(
idToken: googleAuth.idToken,
accessToken: googleAuth.accessToken,
);
assert(user != null);
assert(!user.isAnonymous);
return user;
}
我想要这样间隔5分钟记录
sr_no PROJECT_ID PHASE VACUUM HUMIDITY TEMPERATURE CR_DATE
1 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:38:26.477
2 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:39:26.430
3 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:40:26.447
4 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:41:26.437
5 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:42:33.280
6 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:43:33.267
7 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:44:33.157
8 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:45:33.320
9 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:46:33.293
10 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:47:33.290
11 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:48:33.330
12 3QA12352 0 3.0000 45.0000 55.0000 2018-12-18 09:49:33.350
13 3ewd 0 56.0000 6.0000 12.0000 2018-12-18 16:00:17.883
14 3ewd 2 56.0000 6.0000 12.0000 2018-12-18 16:01:17.757
15 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:02:17.760
16 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:03:17.793
17 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:04:18.123
18 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:05:17.843
19 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:06:17.767
20 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:07:17.887
21 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:08:17.820
22 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:09:17.767
23 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:10:17.800
24 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:11:17.800
25 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:12:17.773
26 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:13:17.797
27 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:14:17.757
28 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:15:17.757
29 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:16:17.770
30 3ewd 2 56.0000 60.0000 56.0000 2018-12-18 16:17:17.803
我该怎么做？
答案 0 :(得分：2)
您可以使用递归CTE在每个项目中生成5分钟的日期时间间隔，然后针对这些间隔加入度量，并检索每个组中的最小度量（按CR_DATE）。
在下面的示例中，我假设sr_no是PRIMARY KEY（或UNIQUE），也是INT和IDENTITY或始终是一个数字增量。我也忽略了表中的所有其他列，因为它们对这个特定问题并不重要（您可以在最后的SELECT中选择所需的任何一个）。
数据样本：
IF OBJECT_ID('tempdb..#Measures') IS NOT NULL
DROP TABLE #Measures
CREATE TABLE #Measures (
sr_no INT IDENTITY,
PROJECT_ID VARCHAR(100),
CR_DATE DATETIME)
INSERT INTO #Measures (
PROJECT_ID,
CR_DATE)
VALUES
('A', '2018-01-01 00:02:26.112'),
('A', '2018-01-01 00:03:26.112'),
('A', '2018-01-01 00:07:26.014'),
('A', '2018-01-01 00:12:26.112'),
('A', '2018-01-01 00:23:43.112'),
('A', '2018-01-01 00:26:26.112'),
('B', '2018-11-26 00:01:26.112'),
('B', '2018-11-25 23:59:00.000'),
('B', '2018-11-26 05:02:26.112')
建议的解决方案：
DECLARE @IntervalMinutes INT = 5
;WITH MaxDateMeasuresByProject AS
(
SELECT
PROJECT_ID = M.PROJECT_ID,
MaxCR_DATE = MAX(M.CR_DATE)
FROM
#Measures AS M
GROUP BY
M.PROJECT_ID
),
RecursiveIntervals AS
(
-- Anchor (minimum CR_DATE by PROJECT_ID)
SELECT
PROJECT_ID = M.PROJECT_ID,
IntervalStart = MIN(M.CR_DATE),
IntervalEnd = DATEADD(MINUTE, @IntervalMinutes, MIN(M.CR_DATE)),
RecursiveLevel = 1
FROM
#Measures AS M
GROUP BY
M.PROJECT_ID
UNION ALL
-- Recursion (minutes added to each project interval, until max available measure)
SELECT
PROJECT_ID = R.PROJECT_ID,
IntervalStart = R.IntervalEnd,
IntervalEnd = DATEADD(MINUTE, @IntervalMinutes, R.IntervalEnd),
RecursiveLevel = R.RecursiveLevel + 1
FROM
RecursiveIntervals AS R
INNER JOIN MaxDateMeasuresByProject AS M ON R.PROJECT_ID = M.PROJECT_ID
WHERE
R.IntervalEnd <= M.MaxCR_DATE
),
FirstMeasureByIntervalByProject AS
(
SELECT
PROJECT_ID = M.PROJECT_ID,
RecursiveLevel = R.RecursiveLevel,
FirstMeasureSR_NO = MIN(M.sr_no)
FROM
#Measures AS M
INNER JOIN RecursiveIntervals AS R ON
M.PROJECT_ID = R.PROJECT_ID AND
M.CR_DATE >= R.IntervalStart AND
M.CR_DATE < R.IntervalEnd
GROUP BY
M.PROJECT_ID,
R.RecursiveLevel
)
SELECT
M.*
FROM
FirstMeasureByIntervalByProject AS F
INNER JOIN #Measures AS M ON F.FirstMeasureSR_NO = M.sr_no
ORDER BY
M.PROJECT_ID,
M.CR_DATE
OPTION
(MAXRECURSION 0)
中间步骤RecursiveIntervals的结果如下（每个项目在最小和最大度量之间间隔5分钟）：
PROJECT_ID IntervalStart IntervalEnd RecursiveLevel
A 2018-01-01 00:02:26.113 2018-01-01 00:07:26.113 1
A 2018-01-01 00:07:26.113 2018-01-01 00:12:26.113 2
A 2018-01-01 00:12:26.113 2018-01-01 00:17:26.113 3
A 2018-01-01 00:17:26.113 2018-01-01 00:22:26.113 4
A 2018-01-01 00:22:26.113 2018-01-01 00:27:26.113 5
B 2018-11-25 23:59:00.000 2018-11-26 00:04:00.000 1
B 2018-11-26 00:04:00.000 2018-11-26 00:09:00.000 2
B 2018-11-26 00:09:00.000 2018-11-26 00:14:00.000 3
B 2018-11-26 00:14:00.000 2018-11-26 00:19:00.000 4
B 2018-11-26 00:19:00.000 2018-11-26 00:24:00.000 5
B 2018-11-26 00:24:00.000 2018-11-26 00:29:00.000 6
B 2018-11-26 00:29:00.000 2018-11-26 00:34:00.000 7
B 2018-11-26 00:34:00.000 2018-11-26 00:39:00.000 8
B 2018-11-26 00:39:00.000 2018-11-26 00:44:00.000 9
B 2018-11-26 00:44:00.000 2018-11-26 00:49:00.000 10
B 2018-11-26 00:49:00.000 2018-11-26 00:54:00.000 11
B 2018-11-26 00:54:00.000 2018-11-26 00:59:00.000 12
B 2018-11-26 00:59:00.000 2018-11-26 01:04:00.000 13
B 2018-11-26 01:04:00.000 2018-11-26 01:09:00.000 14
B 2018-11-26 01:09:00.000 2018-11-26 01:14:00.000 15
B 2018-11-26 01:14:00.000 2018-11-26 01:19:00.000 16
B 2018-11-26 01:19:00.000 2018-11-26 01:24:00.000 17
B 2018-11-26 01:24:00.000 2018-11-26 01:29:00.000 18
B 2018-11-26 01:29:00.000 2018-11-26 01:34:00.000 19
B 2018-11-26 01:34:00.000 2018-11-26 01:39:00.000 20
B 2018-11-26 01:39:00.000 2018-11-26 01:44:00.000 21
B 2018-11-26 01:44:00.000 2018-11-26 01:49:00.000 22
B 2018-11-26 01:49:00.000 2018-11-26 01:54:00.000 23
B 2018-11-26 01:54:00.000 2018-11-26 01:59:00.000 24
B 2018-11-26 01:59:00.000 2018-11-26 02:04:00.000 25
B 2018-11-26 02:04:00.000 2018-11-26 02:09:00.000 26
B 2018-11-26 02:09:00.000 2018-11-26 02:14:00.000 27
B 2018-11-26 02:14:00.000 2018-11-26 02:19:00.000 28
B 2018-11-26 02:19:00.000 2018-11-26 02:24:00.000 29
B 2018-11-26 02:24:00.000 2018-11-26 02:29:00.000 30
B 2018-11-26 02:29:00.000 2018-11-26 02:34:00.000 31
B 2018-11-26 02:34:00.000 2018-11-26 02:39:00.000 32
B 2018-11-26 02:39:00.000 2018-11-26 02:44:00.000 33
B 2018-11-26 02:44:00.000 2018-11-26 02:49:00.000 34
B 2018-11-26 02:49:00.000 2018-11-26 02:54:00.000 35
B 2018-11-26 02:54:00.000 2018-11-26 02:59:00.000 36
B 2018-11-26 02:59:00.000 2018-11-26 03:04:00.000 37
B 2018-11-26 03:04:00.000 2018-11-26 03:09:00.000 38
B 2018-11-26 03:09:00.000 2018-11-26 03:14:00.000 39
B 2018-11-26 03:14:00.000 2018-11-26 03:19:00.000 40
B 2018-11-26 03:19:00.000 2018-11-26 03:24:00.000 41
B 2018-11-26 03:24:00.000 2018-11-26 03:29:00.000 42
B 2018-11-26 03:29:00.000 2018-11-26 03:34:00.000 43
B 2018-11-26 03:34:00.000 2018-11-26 03:39:00.000 44
B 2018-11-26 03:39:00.000 2018-11-26 03:44:00.000 45
B 2018-11-26 03:44:00.000 2018-11-26 03:49:00.000 46
B 2018-11-26 03:49:00.000 2018-11-26 03:54:00.000 47
B 2018-11-26 03:54:00.000 2018-11-26 03:59:00.000 48
B 2018-11-26 03:59:00.000 2018-11-26 04:04:00.000 49
B 2018-11-26 04:04:00.000 2018-11-26 04:09:00.000 50
B 2018-11-26 04:09:00.000 2018-11-26 04:14:00.000 51
B 2018-11-26 04:14:00.000 2018-11-26 04:19:00.000 52
B 2018-11-26 04:19:00.000 2018-11-26 04:24:00.000 53
B 2018-11-26 04:24:00.000 2018-11-26 04:29:00.000 54
B 2018-11-26 04:29:00.000 2018-11-26 04:34:00.000 55
B 2018-11-26 04:34:00.000 2018-11-26 04:39:00.000 56
B 2018-11-26 04:39:00.000 2018-11-26 04:44:00.000 57
B 2018-11-26 04:44:00.000 2018-11-26 04:49:00.000 58
B 2018-11-26 04:49:00.000 2018-11-26 04:54:00.000 59
B 2018-11-26 04:54:00.000 2018-11-26 04:59:00.000 60
B 2018-11-26 04:59:00.000 2018-11-26 05:04:00.000 61
最终结果：
sr_no PROJECT_ID CR_DATE
1 A 2018-01-01 00:02:26.113
4 A 2018-01-01 00:12:26.113
5 A 2018-01-01 00:23:43.113
7 B 2018-11-26 00:01:26.113
9 B 2018-11-26 05:02:26.113
如果每个项目的记录很多且时间很长，则此查询很可能会花费很长时间。在这种情况下，将递归CTE的数据转储到临时表中将加快处理速度。
您还可以更改@IntervalMinutes的值以查看其他间隔的结果。
答案 1 :(得分：1)
我认为这需要递归，因为 5分钟边界是根据前一个边界而不是第一个边界定义的：
WITH rcte AS (
SELECT curr.*
FROM @t AS curr
WHERE NOT EXISTS (
SELECT 1
FROM @t
WHERE PROJECT_ID = curr.PROJECT_ID AND CR_DATE < curr.CR_DATE
)
UNION ALL
SELECT curr.*
FROM rcte AS prev
JOIN @t AS curr ON prev.PROJECT_ID = curr.PROJECT_ID AND curr.CR_DATE >= DATEADD(MINUTE, 5, prev.CR_DATE)
WHERE NOT EXISTS (
SELECT 1
FROM @t
WHERE PROJECT_ID = curr.PROJECT_ID AND CR_DATE < curr.CR_DATE AND CR_DATE >= DATEADD(MINUTE, 5, prev.CR_DATE)
)
)
SELECT *
FROM rcte
rCTE非常简单：