Database Languages – DCL (Data Control Language)
Oracle SQL examples for managing user privileges and access control.
DCL (Data Control Language) is used to control access and permissions on database objects. It focuses on security and authorization rather than data or structure.
1. What is DCL?
- Grant or revoke privileges to/from users.
- Control access to tables, views, sequences, etc.
- Requires DBA or owner privileges.
2. Common DCL Commands
| Command | Purpose | Oracle Example |
|---|---|---|
| GRANT | Give privileges to users | GRANT SELECT, INSERT ON student TO user1; |
| REVOKE | Remove privileges from users | REVOKE INSERT ON student FROM user1; |
3. Oracle Examples in Detail
GRANT Example
GRANT SELECT, UPDATE, DELETE ON employee TO hr_user;
REVOKE Example
REVOKE UPDATE, DELETE ON employee FROM hr_user;
4. Key Points
- DCL commands do not modify data.
- Used to control access and security.
- Requires proper privileges (DBA or object owner).
- Often combined with roles in Oracle.
5. Summary
DCL (Data Control Language) manages user access and privileges in a database. The main commands are GRANT and REVOKE, which ensure data security and controlled access to database objects.
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