Porting from MySql to T-Sql. Any INET_ATON() equivalent?

Question

Need to move some code from MySql to TSql. I have a couple of calls to INET_ATON which converts a string which resembles an IPAddress into a number. Is there a T-SQL equival

Answer 1

Little better. It uses int (4b) instead of bigint (8b). Your result should only be four bytes... one per octet:

create function INET_ATON (@ip varchar(15))
returns int
begin
    declare @rslt int 
    -- This first part is a little error checking
    -- Looks for three dots and all numbers when not dots 
    if len(@ip) - len(replace(@ip,'.','')) = 3 
        AND
            isnumeric(replace(@ip,'.','')) = 1
    begin 
    set @rslt = convert(int,
            convert(binary(1),convert(tinyint,parsename(@ip, 4)))
        +   convert(binary(1),convert(tinyint,parsename(@ip, 3)))
        +   convert(binary(1),convert(tinyint,parsename(@ip, 2)))
        +   convert(binary(1),convert(tinyint,parsename(@ip, 1)))
        )
    end
    else set @rslt = 0
    return @rslt
end;