Quick Answer: What Is Difference Between Delete And Drop?

Which one sorts rows in SQL?

The SQL ORDER BY Keyword The ORDER BY keyword is used to sort the result-set in ascending or descending order.

The ORDER BY keyword sorts the records in ascending order by default.

To sort the records in descending order, use the DESC keyword..

Can we rollback truncate?

You cannot ROLLBACK TRUNCATE Simply, you cannot rollback a transaction if it is already committed but you can do something else to get the data back (or at least some parts of it). When you execute the TRUNCATE statement, your data is still in the MDF file.

What is the use of drop command?

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 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 clear a table in SQL?

To remove one or more rows in a table:First, you specify the table name where you want to remove data in the DELETE FROM clause.Second, you put a condition in the WHERE clause to specify which rows to remove. If you omit the WHERE clause, the statement will remove all rows in the table.

Which is better truncate or delete?

Truncate reseeds identity values, whereas delete doesn’t. Truncate removes all records and doesn’t fire triggers. Truncate is faster compared to delete as it makes less use of the transaction log.

Why Delete is DML and truncate is DDL?

Truncate reinitializes the identity by making changes in data definition therefore it is DDL, whereas Delete only delete the records from the table and doesn’t make any changes in its Definition that’s why it is DML.

Why use truncate instead of delete?

TRUNCATE is faster than DELETE , as it doesn’t scan every record before removing it. TRUNCATE TABLE locks the whole table to remove data from a table; thus, this command also uses less transaction space than DELETE . Unlike DELETE , TRUNCATE does not return the number of rows deleted from the table.

What is difference between delete truncate and drop?

The DROP command removes a table from the database. All the tables’ rows, indexes, and privileges will also be removed. … DROP and TRUNCATE are DDL commands, whereas DELETE is a DML command. DELETE operations can be rolled back (undone), while DROP and TRUNCATE operations cannot be rolled back.

What is the difference between Alter and drop?

Alter is used to modify an existing table, like adding a row or column. Alter preserves the existing data. Example, deleting a column won’t affect the data in the other columns. … Drop is used to remove a table completely.

What is drop SQL?

The DROP TABLE statement is used to drop an existing table in a database.

Can truncate have where condition?

TRUNCATE cannot be executed with a WHERE clause means that all records will be removed from the TRUNCATE / statement. However, partitions can be truncated as shown in the below T-SQL statement. From the above statement, partitions 2,4,6,7,8 will be truncated leaving the other partitions data will not be truncated.

Does truncate free space?

A TRUNCATE statement does not affect any structures associated with the table being truncated (constraints and triggers) or authorizations. A TRUNCATE statement also specifies whether space currently allocated for the table is returned to the containing tablespace after truncation.

What is the difference between delete?

DELETE is a Data Manipulation Language (DML) command and used when you want to remove some or all the tuples from a relation….Comparison Chart:ParameterDELETEDROPLanguageData Manipulation Language commandData Definition Language command.7 more rows•Aug 19, 2019

Is delete a DDL command?

DELETE is a Data Manipulation Language command, DML command and is used to remove tuples/records from a relation/table. … DELETE is DML. DROP is DDL.