SQL中的Agent日期和时间的处理问题

version: 1.0.0.1 

last updated: 22 November 2002

SQL Agent uses two ways to represent date and time information. In some cases it uses the SQL Server datatime data type, but in most occasions it uses two integers to represent the date and time separately. The format of the date and time integers are very straight forward, the date is formatted as YYYYMMDD and the time is formatted as HHMMSS. Everywhere where schedule information is represented the date and time are stored using integers. 

The problem is that you need to convert the integer representation to a datetime, before you can leverage the existing datetime manipulation functions in SQL Server. This article provides helper functions to convert between the two representations. In total there are five user defined functions.

Name Description 
fn_AgentDate2DateTime Converts an SQL Agent integer date representation in to a SQL Server datetime datatype, since the time is not specified, the time is always 00:00:00.000 
fn_AgentTime2DateTime Converts an SQL Agent integer time representation in to a SQL Server datetime datatype, since the date is not specified, the date is always 1900-01-01 
fn_AgentDateTime2DateTime Converts an SQL Agent integer date and time representation in to a SQL Server datetime datatype 
fn_DateTime2AgentDate Converts a SQL Server datetime into an SQL Agent integer date representation 
fn_DateTime2AgentTime Converts a SQL Server datetime into an SQL Agent integer time representation 

Below follows the source code for the five user defined functions:

create function [dbo].[fn_AgentDate2DateTime] (@agentdate int)
returns datetime
as
begin
    declare @date datetime,
            @year int,
            @month int,
            @day int,
            @datestr nvarchar(40)

    select @year = (@agentdate / 10000)
    select @month = (@agentdate - (@year * 10000)) / 100
    select @day = (@agentdate - (@year * 10000) - (@month * 100))

    select @datestr = convert(nvarchar(4), @year) + N'-' + 
                      convert(nvarchar(2), @month) + N'-' + 
                      convert(nvarchar(4), @day)

    select @date = convert(datetime, @datestr)
    
    return @date
end
go

-- example
select [dbo].[fn_AgentDate2DateTime](20020430)
go

create function [dbo].[fn_AgentTime2DateTime](@agenttime int)
returns datetime
as
begin
    declare @date datetime,
            @hour int,
            @min int,
            @sec int,
            @datestr nvarchar(40)

    select @hour = (@agenttime / 10000)
    select @min = (@agenttime - (@hour * 10000)) / 100
    select @sec = (@agenttime - (@hour * 10000) - (@min * 100))

    select @datestr = replace(convert(nvarchar(2), @hour) + N':' + 
                              convert(nvarchar(2), @min) + N':' + 
                              convert(nvarchar(2), @sec), ' ', '0')

    select @date = convert(datetime, @datestr)

    return @date
end
go

-- example
select [dbo].[fn_AgentTime2DateTime] (110015)
go

create function [dbo].[fn_AgentDateTime2DateTime] (@agentdate int, @agenttime int)
returns datetime
as
begin
    declare @date datetime,
            @year int,
            @month int,
            @day int,
            @hour int,
            @min int,
            @sec int,
            @datestr nvarchar(40)

    select @year = (@agentdate / 10000)
    select @month = (@agentdate - (@year * 10000)) / 100
    select @day = (@agentdate - (@year * 10000) - (@month * 100))

    select @hour = (@agenttime / 10000)
    select @min = (@agenttime - (@hour * 10000)) / 100
    select @sec = (@agenttime - (@hour * 10000) - (@min * 100))

    select @datestr = convert(nvarchar(4), @year) + N'-' + 
                      convert(nvarchar(2), @month) + N'-' + 
                      convert(nvarchar(4), @day) + N' ' +
                      replace(convert(nchar(2), @hour) + N':' + 
                              convert(nchar(2), @min) + N':' + 
                              convert(nchar(2), @sec), ' ', '0')

    select @date = convert(datetime, @datestr)

    return @date
end
go

-- example
select [dbo].[fn_AgentDateTime2DateTime] (20020222, 110015)
go

create function [dbo].[fn_DateTime2AgentDate] (@date datetime)
returns int
as
begin
    declare @dateint int

    select @dateint = (datepart(year, @date) * 10000) +
                      (datepart(month, @date) * 100) +
                      (datepart(day, @date))

    return @dateint 
end
go

-- example
select [dbo].[fn_DateTime2AgentDate] (getdate())
go

create function [dbo].[fn_DateTime2AgentTime] (@date datetime)
returns int
as
begin
    declare @timeint int

    select @timeint = (datepart(hour, @date) * 10000) +
                      (datepart(minute, @date) * 100) +
                      (datepart(second, @date))

    return @timeint
end
go

-- example
select [dbo].[fn_DateTime2AgentTime] (getdate())
go