What does DROP do in SQL?
DROP is used to delete a whole database or just a table. The DROP statement destroys the objects like an existing database, table, index, or view. A DROP statement in SQL removes a component from a relational database management system (RDBMS).
Why DROP command is used?
DROP statement is a Data Definition Language(DDL) Command which is used to delete existing database objects. It can be used to delete databases, tables, views, triggers, etc. … DROP is a DDL Command.
What does DROP do in database?
Dropping a database deletes the database from an instance of SQL Server and deletes the physical disk files used by the database. If the database or any one of its files is offline when it is dropped, the disk files are not deleted. These files can be deleted manually by using Windows Explorer.
What is the use of DROP command in MySQL?
The DROP TABLE statement allows a table to be removed from a MySQL database. This statement deletes the entire structure as well as the content of the table.
What is the difference between DELETE and DROP?
DELETE command is a Data Manipulation Language command whereas, DROP is a Data Definition Language Command. The point that distinguishes DELETE and DROP command is that DELETE is used to remove tuples from a table and DROP is used to remove entire schema, table, domain or constraints from the database.
What is DROP and truncate in SQL?
The DROP command is used to remove table definition and its contents. Whereas the TRUNCATE command is used to delete all the rows from the table.
Can DROP be rolled back in SQL?
You cannot roll back a DROP TABLE statement. Note: For an external table, this statement removes only the table metadata in the database.
What is difference between drop table and DROP database?
Answer: DROP DATABASE drops all tables in the database and deletes the database. … … The drop table command is used to delete a table and all rows in the table. … Deleting all of the records in the table leaves the table including column and constraint information.
Can DROP command be rolled back?
The DROP command removes a table from the database. All the tables’ rows, indexes, and privileges will also be removed. No DML triggers will be fired. The operation cannot be rolled back.
How do you do a drop statement in SQL?
SQL DROP TABLE Statement
- DROP TABLE table_name;
- Example. DROP TABLE Shippers;
- TRUNCATE TABLE table_name;
How do you drop a database in SQL?
To delete a database
- In Object Explorer, connect to an instance of the SQL Server Database Engine, and then expand that instance.
- Expand Databases, right-click the database to delete, and then click Delete.
- Confirm the correct database is selected, and then click OK.
How do I drop a MySQL database?
DROP DATABASE using MySQL Workbench
First, launch the MySQL workbench and log in to the MySQL Server. Second, right-click the database that you want to remove, for example, testdb2 and choose the Drop Schema… option. Third, MySQL Workbench displays a dialog to confirm the deletion.
What is the purpose of drop table command in MySQL how is it different from DELETE command?
DELETE is a Data Manipulation Language command, DML command and is used to remove tuples/records from a relation/table. Whereas DROP is a Data Definition Language, DDL command and is used to remove named elements of schema like relations/table, constraints or entire schema.
How is view created and dropped in DBMS?
Views in SQL are kind of virtual tables. A view also has rows and columns as they are in a real table in the database. We can create a view by selecting fields from one or more tables present in the database. A View can either have all the rows of a table or specific rows based on certain condition.
What does drop table cascade constraints do?
Specify CASCADE CONSTRAINTS to drop all referential integrity constraints that refer to primary and unique keys in the dropped table. If you omit this clause, and such referential integrity constraints exist, then the database returns an error and does not drop the table.