SP

--select 1234567%7
--select dbo.udf_checkMawbNumber('1601234567533')
alter function [dbo].[udf_checkMawbNumber]
(
 @mawbNumber char(18)
)
returns char(1)
/*return Y=Valid mawbNumber, N=Invalid mawbNumber*/
as
 Begin
  declare @digitPart int ,
    @lastDigit int ,
    @flag char(1)
  set @flag ='N'  

  if len(@mawbNumber)=11 /*Check if the mawbnumber is 11 characters*/
   Begin
    if patindex(@mawbNumber , '[^0-9]')=0 and isnumeric(@mawbNumber)=1 /*Check if the number is numbers*/
     Begin
      set @digitPart =cast(substring(rtrim(@mawbNumber),4,7) as int)
      set @lastDigit=cast (right(rtrim(@mawbNumber),1) as int)
      if ((@digitPart%7)=@lastDigit)
       Begin
        set @flag='Y'
       End
     End
   End
  return @flag
 End