要实现以下功能，SQL语句如何实现？

1 建立新的管理员账户，将原有管理员账户禁用
alter user xxx with nologin;
2 建立非数据操作类账户，不能执行DML操作，不能执行DDL类语句，该用户可以进行备份，查看数据状态、连接数，等操作。
alter user xxx SET default_transaction_read_only=on;
GRANT CONNECT ON DATABASE your_database TO xxx;
GRANT USAGE ON SCHEMA public TO xxx;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO xxx;

3 建立数据操作类用户，能执行DML，DDL类中不能执行drop语句，不能执行删库、导出数据等语句，限制该用户的数据库连接数。
修改用户连接数限制参考：alter user xxx CONNECTION LIMIT 100;
其他详细权限授权和回收可以参考如下语法
REVOKE [ GRANT OPTION FOR ]
{ { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | ALTER | DROP | COMMENT | INDEX | VACUUM }[, ...]
| ALL [ PRIVILEGES ] }
ON { [ TABLE ] table_name [, ...]
| ALL TABLES IN SCHEMA schema_name [, ...] }
FROM { [ GROUP ] role_name | PUBLIC } [, ...]
[ CASCADE | RESTRICT ];
授权语法：
GRANT { { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | ALTER | DROP | COMMENT | INDEX | VACUUM } [, ...]
| ALL [ PRIVILEGES ] }
ON { [ TABLE ] table_name [, ...]
| ALL TABLES IN SCHEMA schema_name [, ...] }
TO { [ GROUP ] role_name | PUBLIC } [, ...]
[ WITH GRANT OPTION ];
具体根据实际回收或赋予权限