Question: What Does Drop Table Do In SQL?

What happens when you drop a table in SQL?

It completely removes the table structure and associated indexes, statistics, permissions, triggers and constraints.

You might have SQL Views and Stored procedures referencing to the SQL table.

SQL Server does not remove these stored procedures and views.

We need to drop them explicitly..

Are temp tables dropped automatically?

Temp tables are automatically dropped as soon as they go out of scope (the proc that they were created in completes) or the connection that created them closes.

How do I drop a table with constraints in SQL?

State’ — Drop the foreign key constraint by its name ALTER TABLE dbo….Select the tables you want to DROP.Select “Save to new query window”.Click on the Advanced button.Set Script DROP and CREATE to Script DROP.Set Script Foreign Keys to True.Click OK.Click Next -> Next -> Finish.View the script and then Execute.

Are indexes dropped when a table is dropped?

Dropping a table removes the table definition from the data dictionary. All rows of the table are no longer accessible. All indexes and triggers associated with a table are dropped. … All synonyms for a dropped table remain, but return an error when used.

Can you join a table to itself?

A self join allows you to join a table to itself. It is useful for querying hierarchical data or comparing rows within the same table. A self join uses the inner join or left join clause. … Note that referencing the same table more than one in a query without using table aliases will result in an error.

Can we drop primary key?

We can remove PRIMARY KEY constraint from a column of an existing table by using DROP keyword along with ALTER TABLE statement.

Can you join a table to itself in SQL?

The self-join is a special kind of joins that allow you to join a table to itself using either LEFT JOIN or INNER JOIN clause. … Because you cannot refer to the same table more than one in a query, you need to use a table alias to assign the table a different name when you use self-join.

What is difference between drop and delete?

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. … DELETE is DML. DROP is DDL.

How do you check if a table exists in SQL?

To check if a table exists in SQL Server, you can use the INFORMATION_SCHEMA. TABLES table. You can use this table with an IF THEN clause do determine how your query responds whether or not a table exists.

Does Drop Table remove constraints?

DROP TABLE removes tables from the database. … DROP TABLE always removes any indexes, rules, triggers, and constraints that exist for the target table. However, to drop a table that is referenced by a view or a foreign-key constraint of another table, CASCADE must be specified.

How do you drop a database?

To delete a databaseIn 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 table in SQL Server?

Using SQL Server Management StudioIn Object Explorer, select the table you want to delete.Right-click the table and choose Delete from the shortcut menu.A message box prompts you to confirm the deletion. Click Yes. Deleting a table automatically removes any relationships to it.

Why drop table if exists?

The DROP TABLE SQL statement enables you to delete a table from the database. If the table did not exist then attempting to DROP it would cause an error to occur. The DROP TABLE IF EXISTS SQL statement enables a check to see that the table exists prior to attempting the dropping (deletion) of the table.

How do you drop in SQL?

A DROP statement in SQL removes a component from a relational database management system (RDBMS). Syntax: DROP object object_name Examples: DROP TABLE table_name; table_name: Name of the table to be deleted. DROP DATABASE database_name; database_name: Name of the database to be deleted.