Question

我正在尝试处理我的数据库中的以下数据，以返回给定时间戳的给定车辆（在本例中为“Car 1”）的唯一驱动程序。这是一个组成的例子，但应该足够了。

我的代码到目前为止 - 哪个不太符合我的要求：

USE 
    VehicleUse
SELECT
    DISTINCT((CONVERT(VARCHAR, m.CurrentDateTime,20) + ' ' + v.VehicleName + ' ' + m.Driver)) AS [Unique Combo]
    , count(m.CurrentDateTime)
FROM
    Vehicles AS v INNER JOIN
    MainData AS m
    ON l.VehicleID = m.VehicleID
WHERE
    v.VehicleName = 'Car 1' 
GROUP BY
    m.CurrentDateTime 
    , v.VehicleName
    , m.Driver  
ORDER BY 
    [Unique Combo]

示例：预处理

+---------------------+---------+--------+
|      Date Time      | Vehicle | Driver |
+---------------------+---------+--------+
| 2014-01-01 10:01:00 | Car 1   | A      |
| 2014-01-01 10:01:00 | Car 1   | B      |
| 2014-01-01 10:01:00 | Car 1   | B      |
| 2014-01-01 10:03:00 | Car 1   | C      |
| 2014-01-01 10:03:00 | Car 1   | C      |
| 2014-01-01 10:03:00 | Car 1   | D      |
| 2014-01-01 10:03:00 | Car 1   | E      |
| 2014-01-01 10:03:00 | Car 1   | F      |
| 2014-01-01 10:05:00 | Car 1   | A      |
| 2014-01-01 10:05:00 | Car 1   | B      |
| 2014-01-01 10:05:00 | Car 1   | C      |
| 2014-01-01 10:05:00 | Car 1   | D      |
| 2014-01-01 10:05:00 | Car 1   | E      |
+---------------------+---------+--------+

当前结果：

+-----------------------------+-------+
|        Unique Combo         | Count |
+-----------------------------+-------+
| 2014-01-01 10:01:00 Car 1 A |     1 |
| 2014-01-01 10:01:00 Car 1 B |     2 |
| 2014-01-01 10:03:00 Car 1 C |     2 |
| 2014-01-01 10:03:00 Car 1 D |     1 |
| 2014-01-01 10:03:00 Car 1 E |     1 |
| 2014-01-01 10:03:00 Car 1 F |     1 |
| 2014-01-01 10:05:00 Car 1 A |     1 |
| 2014-01-01 10:05:00 Car 1 B |     1 |
| 2014-01-01 10:05:00 Car 1 C |     1 |
| 2014-01-01 10:05:00 Car 1 D |     1 |
| 2014-01-01 10:05:00 Car 1 E |     1 |
+-----------------------------+-------+

期望的结果：

+---------------------+---------+--------------------------------------------+
|      Date Time      | Vehicle | Unique Driver Count For Vehicle @ DateTime |
+---------------------+---------+--------------------------------------------+
| 2014-01-01 10:01:00 | Car 1   |                                          2 |
| 2014-01-01 10:03:00 | Car 1   |                                          4 |
| 2014-01-01 10:05:00 | Car 1   |                                          5 |
+---------------------+---------+--------------------------------------------+

Answer 1

试试这个......

SELECT m.CurrentDateTime AS ' Date Time',v.VehicleName ,COUNT(m.Driver) AS 'Unique Driver Count For Vehicle @ DateTime '
FROM
    Vehicles  v 
    INNER JOIN MainData  m ON l.VehicleID = m.VehicleID
WHERE
    v.VehicleName = 'Car 1' 
GROUP BY
    m.CurrentDateTime 
    , v.VehicleName
ORDER BY CurrentDateTime

Answer 2

我不完全确定您正在使用的SQL风格的确切语法，但我认为您希望对名称和日期进行分组，然后计算驱动程序。

SELECT
    m.CurrentDateTime, v.VehicleName, count(distinct m.Driver)
FROM
    Vehicles AS v INNER JOIN
    MainData AS m
    ON l.VehicleID = m.VehicleID
WHERE
    v.VehicleName = 'Car 1' 
GROUP BY
    m.CurrentDateTime 
    , v.VehicleName
ORDER BY 
    m.CurrentDateTime 
    , v.VehicleName

SQL从3列返回唯一计数 - DateTime，Vehicle，Driver

2 个答案: