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From:SGreen Date:October 3 2005 8:30pm
Subject:Re: Table names with periods
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"Patrick" <patrick@stripped> wrote on 10/03/2005 03:43:20 PM:

> There are many ways to approach this.  How are you receiving the IP 
> data?  Are you reading a file or other stream or are you trying to 
> process the table creation by reading a column from a previously 
> populated table through a select statement?
> 
> The functions, inet_ntoa() and inet_addr(), are part of most 
> networking libraries. These are the common functions to convert 
> dotted quad notation. If you wanted to write you own function, an 
> IPv4 address is broken down as follows:
> 
> AAA.BBB.CCC.DDD
>   \   \   \   \
>     \   \   \   DDD
>       \   \   CCC x CCC
>         \   BBB x BBB x BBB
>           AAA x AAA x AAA x AAA

I am not sure of your algorithm. Perhaps I am just not understanding your 
notation.

> 
> Add the results and you have your unique 32bit number. 
> 
> eg. 10.10.10.1 = 10,000 + 1,000 + 100 + 1
>                = 11,101
> 
Let me try a different number(one a little less friendly to base10):

the address 4.4.4.4:
4^4 + 4^3 + 4^2 + 4 = 256 + 64 + 16 + 4 = 340

Which would be the same as: 2.4.16.4 = 340
your method does not seem to generate unique numbers for each IP 
address....

Maybe I just don't get your description. 


Mathematically speaking: The base10 representation of the 32-bit number 
that 2.30.40.10 corresponds to would be:
(2 * 256*256*256) + (30 * 256*256) + (40 * 256) + 10 = 35530762

Which is the same thing we get from 

mysql>select inet_aton('2.30.40.10');
+-------------------------+
| inet_aton('2.30.40.10') |
+-------------------------+
|                35530762 |
+-------------------------+
1 row in set (0.04 sec)

as was mentioned earlier...

> 
> If you are not able to pre-process (scrub) the incoming data 
> programmatically, you would need to create a UDF in MySQL to perform
> the conversion, or, alternatively, if you want to use MySQL SELECT 
> statement as-is could replace the 'period' with an 'underscore' 
> using MySQL's built-in string functions like so:
> 
> Assumptions: Reading IP address from an existing table named 
> IP_Addresses with a column named ip_address and a column named status.
> 
>     SELECT  "CREATE TABLE ",REPLACE(ip_address,'.','_'), " [insert 
> create options here]" FROM IP_Addresses WHERE status ="ACTIVE"

Dynamic SQL? Not with that statement. He is going to need to create his 
SQL statement client-side and send it pre-formatted to the server. MySQL 
5.0 has the beginnings of dynamic SQL and I am not 100% sure it would 
accept what you typed.

> 
> You would obviously add your "CREATE TABLE" options and "INTO 
> OUTFILE" options as needed.
> This would be an alternative to converting IPv4 to 32bit Integer.
> 
> I hope this helps...
> 
> If at all possible, it is probably best to continue in the MySQL 
> list, there are some pretty clever people out there
> 
> Pat...
> 
> patrick@stripped
> CocoNet Corporation
> SW Florida's First ISP
> 825 SE 47th Terrace
> Cape Coral, FL 33904
> 
>   ----- Original Message ----- 
>   From: Chance Ellis 
>   To: Patrick 
>   Sent: Monday, October 03, 2005 2:22 PM
>   Subject: Re: Table names with periods
> 
> 
>   Patrick,
> 
>   I have been trying to figure out how I can convert an IP address 
> to a 32bit integer within a SQL create statement.

You are mixing purposes. MySQL has a CREATE TABLE statement but it 
requires a string literal. You cannot build a CREATE TABLE statement on 
the fly -inside- MySQL. You have to build your statement client-side and 
send it (as a complete statemnt) to MySQL to process. 

MySQL has a function that converts IP addresses into numbers (see above) 
but you cannot combine that with a CREATE TABLE statement.

> 
>   Is this possible or am I thinking about this all wrong? The input 

Yes, I think you are all wrong. You are being too "literal" in your design 
choices. Generally if your data storage design requires you to add tables 
whenever you add a new "whatever", that is a bad design. The better thing 
to do is to create one table that can hold the entire class of "whatevers" 
and differentiate between them with data markers. I assume that each of 
these IP-named tables would look identical to every other (same column 
names, same column types, ...)?  The preferred method of modelling this is 
to create one table (that looks just like each IP table was going to look) 
and adding a column to it for the IP address. I know I am not the first 
person to recommend this design (I can think of at least two others that 
have also tried). 

Just so that we aren't all telling you to possibly do the wrong thing: Why 
do you feel that individual IP tables is a correct DATABASE design? It may 
be an acceptable PROGRAMMING design (one IP list object per address) but 
this is probably one of those points where good DB design and good OO 
design diverge.

> I am given is a straight IP address. I have no way of modifying it 
> other than some option in the SQL create statement is possible. I 
> want to create a new table for each IP address. Without getting too 
> much into the details, these are my requirements and I have been 
> wasting alot of time trying to figure out how to change this string 
> in the create statement. 
> 
The reason it has been so hard to do what you wanted to do is because what 
you wanted to do is hard to maintain. Either trust us on our design 
recommendation or tell us more about your problem. Depending on what you 
tell us, perhaps neither design is appropriate.  Please, and this goes for 
others reading this later, never be afraid of getting into "too many 
details". The details make all of the difference!! The better you can 
describe your situation, the more likely you are to get a useful response.

<remainder snipped>

Kindest regards,
Shawn Green
Database Administrator
Unimin Corporation - Spruce Pine
Thread
Table names with periodsChance Ellis28 Sep
  • Re: Table names with periodsSGreen28 Sep
  • Re: Table names with periodsMartijn Tonies28 Sep
    • Re: Table names with periodsChance Ellis28 Sep
  • Re: Table names with periodsMartijn Tonies28 Sep
  • Re: Table names with periodsMartijn Tonies28 Sep
    • Re: Table names with periodsChance Ellis28 Sep
  • Re: Table names with periodsPatrick28 Sep
    • Re: Table names with periodsChance Ellis28 Sep
  • Re: Table names with periodsMartijn Tonies28 Sep
  • Re: Table names with periodsOctavian Rasnita28 Sep
  • Re: Table names with periodsPatrick3 Oct
    • Re: Table names with periodsSGreen3 Oct
      • Re: Table names with periodsChance Ellis3 Oct
        • Re: Table names with periodsJasper Bryant-Greene3 Oct
        • Re: Table names with periodsJerl Simpson3 Oct
        • Re: Table names with periodsBastian Balthazar Bux3 Oct
          • Re: Table names with periodsChance Ellis4 Oct
      • Re: Table names with periodsPatrick4 Oct