Question

之前可能已经回答过这个问题，但我甚至不确定如何搜索它，所以如果它重复，我会道歉。

我有一张电话。列包括呼叫开始的时间，呼叫的长度（以秒为单位）以及＆＃34;频道＆＃34;电话进来（1-4的整数）。我想知道所有4个频道被占用的频率。我该如何查询？

例如，考虑样本数据：

CallTime   Length   Channel
12:00      22       1
12:05      15       2
12:10      20       3
12:15      10       4

在这种情况下，所有4个频道都被占用了7分钟（直到第一个呼叫结束）。有没有办法查询这个？

谢谢，

-Scott

Answer 1

DECLARE @MyTable TABLE
(
    CallTime DATETIME,
    CallLength INT,
    Channel INT
)

INSERT INTO @MyTable
( CallTime, CallLength, Channel )
VALUES
( '06-26-2014 12:00:00', 22, 1 ),
( '06-26-2014 12:00:05', 15, 2 ),
( '06-26-2014 12:00:10', 20, 3 ),
( '06-26-2014 12:00:15', 10, 4 );

DECLARE @number_of_numbers INT = 100000;

;WITH
a AS (SELECT 1 AS i UNION ALL SELECT 1),
b AS (SELECT 1 AS i FROM a AS x, a AS y),
c AS (SELECT 1 AS i FROM b AS x, b AS y),
d AS (SELECT 1 AS i FROM c AS x, c AS y),
e AS (SELECT 1 AS i FROM d AS x, d AS y),
f AS (SELECT 1 AS i FROM e AS x, e AS y),
numbers AS 
(
    SELECT TOP(@number_of_numbers)
    ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS number
    FROM f
)


SELECT 
    d.CheckTime,
    MAX(CASE WHEN m.Channel = 1 THEN 1 ELSE 0 END) Channel1,
    MAX(CASE WHEN m.Channel = 2 THEN 2 ELSE 0 END) Channel2,
    MAX(CASE WHEN m.Channel = 3 THEN 3 ELSE 0 END) Channel3,
    MAX(CASE WHEN m.Channel = 4 THEN 4 ELSE 0 END) Channel4
FROM
(
    SELECT DATEADD(SECOND, n.number, '06/26/2014') CheckTime
    FROM numbers n
) AS d
INNER JOIN @MyTable m
    ON d.CheckTime >= m.CallTime AND d.CheckTime <= DATEADD(SECOND, m.CallLength, m.CallTime)
GROUP BY d.CheckTime

下面是一个示例，您可以在其中创建一个数字表，然后使用它创建一天中每一秒的时间段，然后您可以加入您的表并使用group by您可以找到所有的通道活性

SQL查询一段时间

1 个答案: