SQL Server在开始日期和结束日期之间

我正在创建一个内部假日预订系统，我需要将业务逻辑规则落实到位，但我需要检查在开始日期和结束日期之间有多少人被预订，因为例如，2名学徒可能只在1天内被预订，但我无法抓住这两天之间的日期

任何帮助都将不胜感激

下面是作业角色表

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您还没有发布RDBMS，表的名称，或者作业角色表到底应该做什么。。。不过我还是要试试看。我使用递归CTE来生成日期列表，但是使用日期表会更好，我甚至不知道您的RDBMS是否支持这一点。我还发布了下面一个表变量的语法，该表变量填充模拟示例的数据

当然，最终输出需要进行定制，以便执行您需要执行的任何操作。但是，这确实会向您显示多个员工休假的每个日期的列表。在第二个JOIN或WHERE子句中添加额外的条件，以便在必要时对JobRole等其他内容进行筛选

-- Code originally from http://smehrozalam.wordpress.com/2009/06/09/t-sql-using-common-table-expressions-cte-to-generate-sequences/

-- Define start and end limits
DECLARE @todate DATETIME, @fromdate DATETIME
SELECT @fromdate='2014-01-01', @todate=GETDATE()-1

DECLARE @TimeOff TABLE (StartDate DATETIME, EndDate DATETIME, EmployeeID INT)

INSERT INTO @TimeOff (StartDate, EndDate, EmployeeID)
SELECT '1/1/2014', '1/7/2014', 7 UNION 
SELECT '2/1/2014', '2/7/2014', 7 UNION 
SELECT '3/3/2014', '3/9/2014', 7 UNION 
SELECT '2/5/2014', '2/6/2014', 8 

;WITH DateSequence( Date ) AS -- this will list all dates.  Use this if you don't have a date table
  (
    SELECT @fromdate as Date
    UNION ALL 
    SELECT DATEADD(DAY, 1, Date)
    FROM DateSequence
    WHERE Date < @todate
  )

--select result
SELECT DateSequence.Date, TimeOffA.StartDate, TimeOffB.EndDate, TimeOffA.EmployeeID
FROM 
    DateSequence -- a full list of all possible dates
     INNER JOIN 
    @TimeOff TimeOffA ON -- all dates when an employee is on vacation -- replace this with your actual table's name
        DateSequence.Date BETWEEN TimeOffA.StartDate AND TimeOffA.EndDate
     INNER JOIN 
    @TimeOff TimeOffB ON -- all dates when an employee who is NOT employee A is on vacation -- replace this with your actual table's name
        DateSequence.Date BETWEEN TimeOffB.StartDate AND TimeOffB.EndDate AND
        TimeOffA.EmployeeID <> TimeOffB.EmployeeID
option (MaxRecursion 2000)

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您正在使用什么RDBMS Oracle、SQL Server 2008R2、SQLLite等？