need a REGEX pattern to match

Question

need help with validating a 9-digit number.

CANNOT BE 
-----------
000000000
111111111
222222222
333333333
444444444
555555555
666666666
777777777
888888888
999999999

4-5 position(s) CANNOT BE 00 -- 123001234

6-9 position(s) CANNOT BE 00 -- 234550000

The nine numbers CANNOT BE sequential -- but only the following 4 four below, for the time being --

012345678
123456789
987654321
098765432

I had just managed to get the first piece done --

"^(?:(?!0+|1+|2+|3+|4+))\d{9}$"

Thanks a TON for the help friends.

Answer 1

A single regex to validate all your rules may exist, but it will be much more easier, readable and maintainable if you write a validation rule (which can be a regex) for each of your criteria.

And as a more general comment, regex are usually great to check what a string IS, but they are not that good when it comes to check what a string IS NOT.