滥用parsname函数：
create function INET_ATON (@addr varchar(15))returns bigintwith schemabindingasbegin return cast(parsename(@addr, 4) as bigint) * 16777216 + cast(parsename(@addr, 3) as bigint) * 65536 + cast(parsename(@addr, 2) as bigint) * 256 + cast(parsename(@addr, 1) as bigint)end
不过，此处不支持“简写地址”。
