There is a table mr_patients with a primary key constraint on a column MRN numeric(10,0) (I did not design the database).
when i do "select * from mr_patients where mrn = 12442" i get zero results
when i do "insert into mr_patients (mrn, plus other columns) select mrn, plus other columns from <anothertable> where anothertable.mrn = 12442" I get a primary key violation that specifies 12442 as the duplicate key.
I have tried dbcc checkdb and specifically check table and reindex all to no avail.
I am looking for other ideas. This is SQLServer express 2019 (15.0.2000)