Postgres 14

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select version();

version

PostgreSQL 14.10 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-20), 64-bit

SELECT 1

create table items (partno text); 
insert into items (partno)
     values ('100H'), ('250H300'), ('etc.'), ('DISCOUNT'),('REBATE');

CREATE TABLE

INSERT 0 5

select * 
  from items
 where partno !~ '\d';

partno

etc.

DISCOUNT

REBATE

SELECT 3