ERROR 42501: Permission denied for table in Postgres

Error Message#

ERROR: permission denied for table users

Description#

This error occurs when a user attempts to perform an operation on a table without having the necessary privileges. It can happen during SELECT, INSERT, UPDATE, DELETE operations or when accessing tables through JOINs.

Causes#

• User lacks required permissions for the operation
• Missing schema usage permissions
• Incorrect search path configuration
• Role membership issues
• Row-level security policies blocking access

Solutions#

1. Grant appropriate permissions#

-- Grant specific permission
GRANT SELECT ON table_name TO user_name;

-- Grant multiple permissions
GRANT SELECT, INSERT, UPDATE ON table_name TO user_name;

2. Grant schema permissions#

GRANT USAGE ON SCHEMA schema_name TO user_name;

3. Check current permissions#

-- For tables
SELECT grantee, privilege_type
FROM information_schema.role_table_grants
WHERE table_name = 'mytable';

-- For schemas
SELECT * FROM information_schema.role_usage_grants
WHERE object_name = 'myschema';

4. Add user to role#

GRANT role_name TO user_name;

5. Change object ownership#

ALTER TABLE mytable OWNER TO newowner;