Sql datetime类型数据默认1900

alter procedure Asset_sspExcuteTicket
(
     @pi_Action varchar(200),
     @pi_TicketMoney3 money,
     @pi_CompanyNote varchar(50),
     @pi_ContractCode varchar(50),
     @pi_TicketType2 varchar(50),
     @pi_TicketMoney money,
     @pi_InfoId bigint,
     @pi_TicketType3 varchar(50),
     @pi_TicketMoney1 money,
     @pi_TicketMoney4 money,
     @pi_TicketType varchar(50),
     @pi_TicketType4 varchar(50),
     @pi_TicketType1 varchar(50),
     @pi_TicketMoney2 money,
@pi_DateDuan1 smalldatetime,
@pi_DateDuan2 smalldatetime,
@pi_DateDuan3 smalldatetime,
@pi_DateDuan4 smalldatetime,
@pi_DateDuan5 smalldatetime,
@pi_DateDuan6 smalldatetime,
@pi_DateDuan7 smalldatetime,
@pi_DateDuan8 smalldatetime,
@pi_DateDuan9 smalldatetime,
@pi_DateDuan10 smalldatetime,
     @po_Status int output,
     @po_RetValue varchar(200) output
)
 as

 if @pi_Action='add'
 begin
    insert into Asset_Ticket
    (
      TicketMoney3,
      CompanyNote,
      ContractCode,
      TicketType2,
      TicketMoney,     
      TicketType3,
      TicketMoney1,
      TicketMoney4,
      TicketType,
      TicketType4,
      TicketType1,
      TicketMoney2,
DateDuan1,
DateDuan2,
DateDuan3,
DateDuan4,
DateDuan5,
DateDuan6,
DateDuan7,
DateDuan8,
DateDuan9,
DateDuan10
    )
  values
    (
      @pi_TicketMoney3,
      @pi_CompanyNote,
      @pi_ContractCode,
      @pi_TicketType2,
      @pi_TicketMoney,     
      @pi_TicketType3,
      @pi_TicketMoney1,
      @pi_TicketMoney4,
      @pi_TicketType,
      @pi_TicketType4,
      @pi_TicketType1,
      @pi_TicketMoney2,
cast(nullif(@pi_DateDuan1,'') as datetime),
cast(nullif(@pi_DateDuan2,'') as datetime),
cast(nullif(@pi_DateDuan3,'') as datetime),
cast(nullif(@pi_DateDuan4,'') as datetime),
cast(nullif(@pi_DateDuan5,'') as datetime),
cast(nullif(@pi_DateDuan6,'') as datetime),
cast(nullif(@pi_DateDuan7,'') as datetime),
cast(nullif(@pi_DateDuan8,'') as datetime),
cast(nullif(@pi_DateDuan9,'') as datetime),
cast(nullif(@pi_DateDuan10,'') as datetime)
    )
      set @po_status = 100
      set @po_RetValue='增加成功'
 end
 if @pi_Action='modify'
 begin
   update Asset_Ticket set
      TicketMoney3=@pi_TicketMoney3,
      CompanyNote=@pi_CompanyNote,     
      TicketType2=@pi_TicketType2,
      TicketMoney=@pi_TicketMoney,     
      TicketType3=@pi_TicketType3,
      TicketMoney1=@pi_TicketMoney1,
      TicketMoney4=@pi_TicketMoney4,
      TicketType=@pi_TicketType,
      TicketType4=@pi_TicketType4,
      TicketType1=@pi_TicketType1,
      TicketMoney2=@pi_TicketMoney2,
DateDuan1=cast(nullif(@pi_DateDuan1,'') as datetime),
DateDuan2=cast(nullif(@pi_DateDuan2,'') as datetime),
DateDuan3=cast(nullif(@pi_DateDuan3,'') as datetime),
DateDuan4=cast(nullif(@pi_DateDuan4,'') as datetime),
DateDuan5=cast(nullif(@pi_DateDuan5,'') as datetime),
DateDuan6=cast(nullif(@pi_DateDuan6,'') as datetime),
DateDuan7=cast(nullif(@pi_DateDuan7,'') as datetime),
DateDuan8=cast(nullif(@pi_DateDuan8,'') as datetime),
DateDuan9=cast(nullif(@pi_DateDuan9,'') as datetime),
DateDuan10=cast(nullif(@pi_DateDuan10,'') as datetime)
     where ContractCode=@pi_ContractCode
     set @po_status = 101
     set @po_RetValue='修改成功'
 end
 if @pi_Action='delete'
 begin
      delete from Asset_Ticket where ContractCode=@pi_ContractCode
      set @po_status = 103
      set @po_RetValue='删除成功'
end
if @@error <> 0
begin
 set @po_status = 900
 set @po_RetValue = '数据执行失败'
end