sql中如何加判断，让这个存储过程只执行一次

CREATE Proc [dbo].[OA_LeaseContract_Finance_Proce_Init]
@LTID int,
@LogName varchar(30)
as
Begin
declare @d1 datetime,@d2 datetime,@Term int,@PriceMonth numeric(18,2),@d3 int,@sysFinanceNumber bigint

select @sysFinanceNumber=a.Sys_FinanceNumber
,@d1=a.BeginDate,@d2=a.EndDate
,@Term=a.Pay_Cyc
,@d3=a.Ahead_Date
,@PriceMonth=a.Price
from OA_LeaseContract a
where LTID=@LTID;


declare @TB table
(
[id] [int] IDENTITY(1,1) NOT NULL,
HF_Date datetime,
BeginDate datetime,
EndDate datetime,
Pay_Price numeric(18,2),
Pay_Price2 numeric(18,2),
Get_Price2 numeric(18,2)
)

declare @dtmp datetime
set @dtmp=@d1
while @dtmp<=@d2
Begin
insert into @TB(BeginDate,EndDate,HF_Date)
values(@dtmp,dateadd(d,-1,DATEADD(m,@Term,@dtmp)),@dtmp-@d3)
set @dtmp=dateadd(m,@Term,@dtmp)
--insert into @TB(Awakeday)
--values(@dtmp-@d3)
--Select case when Advanceday > 0
--then Select id,DATEADD(day,-Advanceday,BeginDate) end from @TB
End

update @TB set Pay_Price=@PriceMonth*@Term
update @TB set EndDate=@d2 where EndDate>@d2
update @TB set Pay_Price2 = -@PriceMonth*2 where EndDate>@d2 or EndDate=@d2
update @TB set Pay_Price2 = @PriceMonth*2 where id = 1
update @TB set Pay_Price2 = 0 where BeginDate>@d1 and EndDate<@d2
--update @TB set HF_Date = null where id = 1
update @TB set Get_Price2 = -Pay_Price2
insert into OA_LeaseContract_Finance(Sys_FinanceNumber,LTID,HF_Date,BeginDate,EndDate
,Pay_Price,Pay_Price2,Get_Price2
,CreateUser)
select @sysFinanceNumber,Ltid=@LTID,HF_Date,BeginDate,EndDate
,Pay_Price,Pay_Price2,Get_Price2,@LogName
from @TB a
order by a.id

End

--select top 1 * from @TB order by BeginDate desc


GO

以上是存储过程代码，如何加判断让他只执行一次，现在是每执行一次，数据就写进去一次，如何修改？不太会sql求解答