1.创建一个用户名为readonly密码为ropass的用户

CREATE USER readonly WITH ENCRYPTED PASSWORD 'ropass';

2.用户只读事务

alter user readonly set default_transaction_read_only=on;

3.把所有库的语言的USAGE权限给到readonly

GRANT USAGE ON SCHEMA public to readonly;

4.授予select权限(这句要进入具体数据库操作在哪个db环境执行就授予那个db的权)

grant select on all tables in schema public to readonly;

第四步，切换到指定的数据执行，切记.

命令行：

连接数据库, 默认的用户和数据库是postgres
psql -U user -d dbname

切换数据库,相当于mysql的use dbname
\c dbname

gui：

 

以上所有操作均可才在navicate和gui桌面sql中，pgsql命令行中执行。

删除角色bug：

How To Drop A Postgres Role/User With privileges

用户角色名：jack（示例）

 Quick way to drop the user

• On default database

postgres=# REASSIGN OWNED BY jack TO postgres;
postgres=# DROP OWNED BY jack;

• Repeat above step on the database which is showed about DETAIL: 3 objects in database mydatabase

mydatabase=# REASSIGN OWNED BY jack TO postgres;
mydatabase=# DROP OWNED BY jack;
mydatabase=# DROP USER jack;

3. Another way: REVOKE all privileges in the privilege_type list

postgres=# REVOKE TRUNCATE, REFERENCES, TRIGGER ON ALL TABLES IN SCHEMA public FROM jack;

bug参考：How To Drop A Postgres Role/User With privileges - DEV Community