创建一个从其他表导入的按时间排序的过程？

问题描述

我正在尝试使用两个datetime值对查询进行排序，但无法正常工作。 它只是抱怨日期时间格式。

当我尝试执行以下命令时收到此错误消息

exec GetSingleAvailability @MachineID = 1002

从字符转换日期和/或时间时转换失败 字符串。

这里是我的程序：

ALTER PROCEDURE [dbo].[GetSingleAvailability]
    -- Add the parameters for the stored procedure here
@MachineID int

AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- Insert statements for procedure here
    DECLARE @Availabilitytime datetime
    DECLARE @TimeNow datetime

    set @Availabilitytime = (SELECT Availabilitytime FROM dbo.machines Where MachineID = @MachineID)
    set @TimeNow = (SELECT GETDATE() AS time)
        DECLARE @query nvarchar(150)
        set @query = 'SELECT AVG(effectively) FROM ['+ Convert(nvarchar,@MachineID) +'] WHERE time between '+ @Availabilitytime +' and '+ @TimeNow +''
    EXECUTE sp_executesql @query 

END

解决方法

您的过程可能需要固定一些：

ALTER Proc GetSingleAvailability (@MachineID int) as
begin
    set nocount on
    declare @Availabilitytime datetime,@TimeNow datetime,@query nvarchar(150)

    select
          @Availabilitytime =
                (select AvailabilityTime from machines where MachineID = @MachineID),@TimeNow = getDate(),@query = N'select avg(effectively) from '
                + quoteName(convert(nvarchar,@MachineID))
                + N' where [time] between '
                + quoteName(convert(nvarchar,@Availabilitytime,120),nchar(39))
                + N' and '
                + quoteName(convert(nvarchar,@TimeNow,nchar(39))

    execute sp_executesql @query
end

如果只需要时间（120）部分，请将8更改为hh:mm:ss。

,

找到了这样的解决方案：

    USE [MITestdb]
GO
/****** Object:  StoredProcedure [dbo].[GetSingleAvailability]    Script Date: 2020-09-11 20:10:47 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:      <Author,Name>
-- Create date: <Create Date,>
-- Description: <Description,>
-- =============================================
ALTER PROCEDURE [dbo].[GetSingleAvailability]
    -- Add the parameters for the stored procedure here
@MachineID int

AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- Insert statements for procedure here
    DECLARE @Availabilitytime datetime
    DECLARE @TimeNow datetime

    set @Availabilitytime = (SELECT Availabilitytime FROM dbo.machines Where MachineID = @MachineID)
    set @TimeNow = (SELECT GETDATE())
        DECLARE @query nvarchar(150)
        set @query = 'SELECT AVG(effectively) FROM ['+ Convert(nvarchar,@MachineID) +'] WHERE time between @qAvailabilitytime and @qTimeNow'
    EXECUTE sp_executesql @query,N'@qAvailabilitytime datetime,@qTimeNow datetime',@qAvailabilitytime = @Availabilitytime,@qTimeNow = @TimeNow

END