psycopg2.errors.InvalidForeignKey: there is no unique constraint matching given keys for referenced table "res_users" answer its becuase of odoo conf soft and hard limits i resolve this issue by increase limit_memory_hard = 9999999999 limit_memory_soft = 9999999999 limit_request = 8192 limit_time_cpu = 1200 limit_time_real = 1200

I had the same issue after restored a database

my env : odoo v15 enterprise version with postgresql v14

i used the answer of rafiul but i found that the is more than one hundred table with missing primary key after restored.

So after found this answer https://stackoverflow.com/questions/60523568/add-primary-key-to-all-tables-in-database-that-dont-have-one-yet , i customized the command to have this one. You can use it in case you want to set the column id as a primary key for all table where primary key is missing.

DO $$
DECLARE row RECORD;
BEGIN
  FOR row IN 
    SELECT tab.table_schema, tab.table_name
    FROM information_schema.tables tab
    LEFT JOIN information_schema.table_constraints tco 
          ON tab.table_schema = tco.table_schema
          AND tab.table_name = tco.table_name 
          AND tco.constraint_type = 'PRIMARY KEY'
    WHERE tab.table_type = 'BASE TABLE'
          AND tab.table_schema not in ('pg_catalog', 'information_schema')
          AND tco.constraint_name is null
          AND tab.table_name in (SELECT table_name FROM information_schema.columns WHERE column_name = 'id')
    ORDER BY table_schema, table_name 
    LOOP 
        EXECUTE 'ALTER TABLE "' || row.table_schema || '"."' || row.table_name  || '" ADD CONSTRAINT PK_' || row.table_name  || ' PRIMARY KEY (ID)';
    END LOOP;  
END;
$$;

YOU CAN RUN IT IN PGADMIN

did you find any solution 
if you have, please tell me how to fix it

hello ,  see below answers i hope will help you :

https://stackoverflow.com/questions/11966420/what-is-causing-error-there-is-no-unique-constraint-matching-given-keys-for-ref

see This https://bugs.launchpad.net/openobject-server/+bug/897098