"column c.relhasoids does not exist at character 245"
It could most possibly due to the version mismatch between psql and your database. It is most likely that we use psql v12 to access database v11. pg_class in v11 has a column named "relhasoid", but in v12, there is no such column, that should be the cause of the issue.
Here below is the link of pg_class table between the two versions:
https://www.postgresql.org/docs/11/catalog-pg-class.html
https://www.postgresql.org/docs/12/catalog-pg-class.html
This issue could also be due to old version of pgadmin if you are using it. For other causes, please kindly check this link
1. Check the psql binary version if it matches your server version.
2. Check your client tool if it is compatible with your DB server version, especially for v12 and above.