ni ➜ ~ createdb IB_lab_5
ni ➜ ~ psql -U postgres -d IB_lab_5
psql (11.5)
Введите "help", чтобы получить справку.

IB_lab_5=# CREATE USER lab_super_user WITH ENCRYPTED PASSWORD 'secret';
CREATE ROLE
IB_lab_5=# CREATE USER lab_readonly_user WITH ENCRYPTED PASSWORD 'secret';
CREATE ROLE
IB_lab_5=# CREATE USER lab_write_user WITH ENCRYPTED PASSWORD 'secret';
CREATE ROLE
IB_lab_5=# GRANT ALL PRIVILEGES ON DATABASE IB_lab_5 TO lab_super_user;
GRANT
IB_lab_5=# GRANT CONNECT ON DATABASE IB_lab_5 TO lab_readonly_user;
GRANT
IB_lab_5=# GRANT USAGE ON SCHEMA public TO lab_readonly_user;
GRANT
IB_lab_5=# GRANT SELECT ON ALL TABLES IN SCHEMA public TO lab_readonly_user;
GRANT
IB_lab_5=# GRANT CONNECT ON DATABASE IB_lab_5 TO lab_write_user;
GRANT
IB_lab_5=# GRANT USAGE ON SCHEMA public TO lab_write_user;
GRANT
IB_lab_5=# CREATE TABLE account(
IB_lab_5(# user_id serial PRIMARY KEY,
IB_lab_5(# username VARCHAR (50) UNIQUE NOT NULL,
IB_lab_5(# password VARCHAR (50) NOT NULL
IB_lab_5(# )
IB_lab_5-# ;
CREATE TABLE
IB_lab_5=# GRANT SELECT ON account TO lab_write_user;
GRANT
IB_lab_5=# GRANT INSERT ON account TO lab_write_user;
GRANT
# TEST WRITE FROM SUPERUSER
IB_lab_5=# SET ROLE lab_write_user;
SET
IB_lab_5=> INSERT INTO account VALUES(1, 'user', 'pass');
INSERT 0 1
# TEST READ AND WRITE FROM SUPERUSER
IB_lab_5=> SET ROLE lab_readonly_user;
SET
IB_lab_5=> INSERT INTO account VALUES(1, 'user', 'pass');
ERROR:  permission denied for table account
IB_lab_5=> SELECT * FROM account;
 user_id | username | password
---------+----------+----------
       1 | user     | pass
(1 строка)
# TEST CREATE TABLE FROM SUPERUSER
IB_lab_5=> SET ROLE lab_super_user;
SET
IB_lab_5=> CREATE TABLE test(
id serial PRIMARY KEY,
value VARCHAR (50) UNIQUE NOT NULL
);
CREATE TABLE