SQL DROP command is used to delete database objects, such as tables, views, indexes, constraints or procedures. The syntax is: DROP [object type] object name. Where the object type can be DATABASE, VIEW, INDEX, CONSTRAINT, PROCEDURE, or FUNCTION, and the object name is the name of the object to be deleted. This command permanently deletes the object, so use it with caution.
DROP command in SQL
Purpose:Delete database objects, such as tables and views , index, constraint or procedure.
Syntax:
DROP [DATABASE | VIEW | INDEX | CONSTRAINT | PROCEDURE | FUNCTION] object_name;
Parameters:
- DATABASE: Delete the database.
- VIEW: Delete the view.
- INDEX: Delete the index.
- CONSTRAINT: Remove constraints.
- PROCEDURE: Deletion process.
- FUNCTION: Delete function.
- object_name: The name of the object to be deleted.
Usage:
The DROP command is used to permanently delete database objects. Use this command with caution because once deleted, it cannot be restored.
Example:
- Drop table:
DROP TABLE table_name;
- Delete view:
DROP VIEW view_name;
- Delete index:
DROP INDEX index_name;
- Delete constraint:
DROP CONSTRAINT constraint_name;
- Delete Procedure:
DROP PROCEDURE procedure_name;
Note:
- Before deleting the object, you need to have delete permission.
- Make sure that the object does not depend on other objects, otherwise it may cause errors.
- When you delete a database, all objects and data in the database will be lost.
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