What methods exist to prevent unwanted data modifications in a database table?

The following methods are used to prevent unwanted changes to database table data:

• Integrity Constraints: such as PRIMARY KEY, UNIQUE, CHECK, FOREIGN KEY, which restrict the type and range of permissible data.
• Triggers: automatic procedures that can block or roll back changes when business logic is violated.
• Permissions: setting roles and user rights so that only authorized persons can modify data.
• Data versioning: storing change history for rollback capability.
• Use of transactions: to ensure changes are atomic and can be rolled back in case of errors.

Example of permission restriction in SQL:

REVOKE UPDATE ON table_name FROM public;
GRANT UPDATE ON table_name TO specific_user;

Thus, only a specific user can modify data, reducing the risk of unwanted changes.