"ERROR: column rel.relhasoids does not exist" with PostgreSQL 12 and PgAdmin 4.3 I get the following error when trying to select rows from a table:
ERROR:  column rel.relhasoids does not exist
LINE 1: SELECT rel.relhasoids AS has_oids

Configuration is:

Linux RHL8
NAME=&quot;Red Hat Enterprise Linux&quot;
VERSION=&quot;8.2 (Ootpa)&quot;
postgresql12-server-12.3
psql (12.3)
PgAdmin 4.3 en 4,5
The column relhasoids has been dropped from the system catalog pg_class in PostgreSQL v12, because the long deprecated WITH OIDS clause has been removed from CREATE TABLE.
Obviously you are using an old version of pgAdmin 4 that has not got the message yet.
Upgrade to a newer version of pgAdmin, and the error should vanish.