Beginners Guide to SQL – SQL DROP Statement

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(SQL Tutorials for Citizen Data Scientist)

SQL DROP Statement

In this tutorial you will learn how to delete database and table using SQL.

Removing a Table from Database

You can use the DROP TABLE statement to easily delete the database tables that you no longer need. The DROP TABLE statement permanently erase all data from the table, as well as the metadata that defines the table in the data dictionary.

Syntax

The DROP TABLE removes one or more tables. The syntax can be given with:

DROP TABLE table1_nametable2_name, …;

Here, table1_nametable2_name, … are the names of the tables that you want to delete.

Warning: Dropping a database or table is irreversible. So, be careful while using the DROP statement, because database system generally do not display any alert like “Are you sure?”. It will immediately delete the database or table and all of its data.

Let’s try to remove a database table using the DROP TABLE statement.

If you remember back to create table chapter, we’ve created a table persons in our demo database. The following statement will remove this table permanently from the database.

Example

DROP TABLE persons;

After executing the above command, if you try to perform any operation on the persons table, like selecting the records from it, you’ll get an error message.


Removing Database

Similarly, you can delete a database using the DROP DATABASE statement. The following command will permanently remove the demo database from the database server.

DROP DATABASE demo;

Now if you try to select the demo database using the USE demo; statement, you’ll get an error message saying “Unknown database” or “Database does not exist”.

 

Beginners Guide to SQL – SQL DROP Statement

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