Issue: ERROR: cannot execute nextval() in a read-only transaction

 

Solution: Go >> C:\Program Files\PostgreSQL\11\share, open postgresql.conf and replaced default_transaction_read_only  to off as `default_transaction_read_only = off`

Also here: C:\Program Files\PostgreSQL\11\data, open postgresql.conf and replaced default_transaction_read_only  to off as `default_transaction_read_only = off`

In command line: 

ALTER SYSTEM SET default_transaction_read_only = off;

See the result: Select name, setting from pg_settings where name ='default_transation_read_only'

---------------------------------------------------------------------
user=# SET SESSION CHARACTERISTICS AS TRANSACTION READ ONLY;
SET
user=# SHOW transaction_read_only;
 transaction_read_only
-----------------------
 on
(1 row)