Copy-ready commandSQL ALTER TABLE — Basic Usage Help and Syntax
HELP 'ALTER';Production warning
Help and syntax commands are generally read-only. The original command shown for context may change systems or data; review it before execution.
Requirements and permissions
- Requirements
- Appropriate database client and connection
- Permissions
- No elevated permissions are normally required to view help; local policy and shell access still apply.
- Last reviewed
- 2026-07-31
Examples
Display the full reference
Uses an interactive database help statement where supported to review syntax and related topics.
HELP 'ALTER';Original command context
The original SQL ALTER TABLE — Basic Usage example is included for context. Review all parameters before using it in production.
ALTER TABLE users ADD COLUMN last_login DATETIME NULL;Common errors
No help topic was found
Use the database client documentation command, such as PostgreSQL \h, or consult the server version documentation.