alpha numeric sequences

  • From: Dba DBA <oracledbaquestions@xxxxxxxxx>
  • To: ORACLE-L <oracle-l@xxxxxxxxxxxxx>
  • Date: Tue, 12 Jun 2012 10:09:50 -0400

There are alot of posts on the web about this, but I have  not seen what I
am looking for.
I have a 10 digit field that is populated with a sequence. We are running
out of numbers. Since we interface with external systems, we were told we
cannot increase the length of this field. However, we can change it to a
varchar and make it alpha-numeric. So we can have A-Z, 0-9 in each digit.
(I don't think we want mixed case. That could be  confusing).
So we can have 36 possible characters in each digit.

I am trying to find the easiest way to do this. I would like to base it on
a sequence as a seed. I tried using to_char to convert to hexadecimal, but
when I need 11 digits converted, I get a length 11 result back. So this
isnt work.

from dual

----------- ----------------------------------------
 174876E7FF                                       11

If I do 10 x's I get back a bunch of pounds.

i saw posts on the web using a with clause. And a modulus and the chr
values. The trick with this is that the capital letters in the alphabet are
chr 65-90. So when I want digits, i need to use a case statement based on
the mod I get back. I also thought about


and then using a substring based off a module of a sequence value for each
Both of these would request that I use a sys_connect by prior and convert
each digit.
There is also the possibility of DBMS_RANDOM and then doing a primary key
query to check for dupes. Not optimal, but it might work.

I wanted to show that I did spend time trying to figure out how to do this.
Anyone know the easiest way to do this?


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