Dynamically search for same digits

Question

I need help with the most efficient way to search for same digits in ids dynamically.
After I queried my table: select MyId from Mytable then I need to check if none of these ids consist of the same repeating digits such as 0000,1111,2222,......9999
To make it more complicated, MyId doesn't have a fix length, it can be 4 digits length or 5, 6 all the way to 9. So the search of the same digits it this ids also should also correspond to the length of the ids.
If MyId is 4 digit long, I should make sure none of the MyId contains 0000,1111,2222,33333,...all the way to 9999
Can anyone give me example on how to do this efficienly since I may deal with large records.

Answer 1

It's Sybase, I think version 4.0 (?) and the datatype for MyId is varchar because it can accept alpha numeric. But we don't bother checking MyId other than 1111,2222,3333, all the way to 9999 if MyId happen to be 4 char length. Or 11111111,22222222,33333333, etc if it happens to be 8 char length.
Within 1 batch, when MyId is 4 char length, all will be 4 char length.
In tomorrow's batch, MyId can be 6 char length and next month it may be 4, 6 char length or 7 char lenght. Max char length for MyId is 9 char length.
So, within 1 batch there will be no mixing of MyId's char length.
I'm thinking of doing Len(MyId) first to find out the lenght of MyId for this batch, then looping to create 111,222,333,etc for the length determined by Len(MyId) and before moving to the next same digit, I do select MyId where MyId Like '%1111....%', then if recordcount is not 0 do something, then move to the next same digit and so on.
But I'm not sure how to write that efficiently when processing 5000 or more records for example.