Quick Answer: What Happens If We Drop A Table?

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..

Do I need to commit after drop table?

CREATE TABLE and DROP TABLE statements do not commit a transaction if the TEMPORARY keyword is used. … SELECT causes an implicit commit before and after the statement is executed when you are creating nontemporary tables. (No commit occurs for CREATE TEMPORARY TABLE … SELECT .)

Why use truncate instead of delete?

TRUNCATE TABLE is faster and uses fewer system resources than DELETE , because DELETE scans the table to generate a count of rows that were affected then delete the rows one by one and records an entry in the database log for each deleted row, while TRUNCATE TABLE just delete all the rows without providing any …

Which command is used to delete the table?

drop table commandThe drop table command is used to delete a table and all rows in the table. To delete an entire table including all of its rows, issue the drop table command followed by the tablename. drop table is different from deleting all of the records in the table.

Do indexes get 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 we drop a table with primary key?

The syntax to drop a primary key in SQL is: ALTER TABLE table_name DROP PRIMARY KEY; table_name. The name of the table to modify.

How do you drop a table with foreign key 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.

Can we drop a table which has primary key?

Yes, you can. But you need to delete the foreign key constraint first in the database. Without the relationship constraints, you can pretty much drop the entire table containing the primary key as there are no more dependencies.

Does dropping a table delete the data?

The DROP TABLE is another DDL (Data Definition Language) operation. But it is not used for simply removing data from a table; it deletes the table structure from the database, along with any data stored in the table.

What are dropped automatically when table dropped?

By default, MS Sql Server also drops indexes when a table is dropped. … MySQL also drops table indexes when tables are dropped.

What is difference between drop and 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.

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 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.

Can we drop a table that has dependent views on it?

DROP TABLE always removes any indexes, rules, triggers, and constraints that exist for the target table. … (CASCADE will remove a dependent view entirely, but in the foreign-key case it will only remove the foreign-key constraint, not the other table entirely.)

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 a table if it exists in SQL?

SQL Server DROP TABLEFirst, specify the name of the table to be removed.Second, specify the name of the database in which the table was created and the name of the schema to which the table belongs. The database name is optional. … Third, use IF EXISTS clause to remove the table only if it exists.

When you drop a table all its trigger objects are deleted with it?

Dropping a table invalidates dependent objects and removes object privileges on the table. If you want to re-create the table, then you must regrant object privileges on the table, re-create the indexes, integrity constraints, and triggers for the table, and respecify its storage parameters.

What is drop database?

Description. DROP DATABASE drops all tables in the database and deletes the database. … To use DROP DATABASE, you need the DROP privilege on the database. DROP SCHEMA is a synonym for DROP DATABASE . Important: When a database is dropped, user privileges on the database are not automatically dropped.