What does TRUNCATE do in SQL?

What does TRUNCATE do in SQL?

TRUNCATE TABLE removes all rows from a table, but the table structure and its columns, constraints, indexes, and so on remain. To remove the table definition in addition to its data, use the DROP TABLE statement.

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.

How do I TRUNCATE a SQL database?

The below script accomplishes this in an automated fashion, by executing the following steps:

1. Create a table variable to store the constraint drop and creation scripts for the database.
2. Load the data for all tables in the database.
3. Execute a cursor to drop all constraints.
4. Truncate all tables.
5. Recreate all the constraints.

What is difference between drop delete and TRUNCATE?

DROP statement is a Data Definition Language(DDL) Command which is used to delete existing database objects. Unlike TRUNCATE which only deletes the data of the tables, the DROP command deletes the data of the table as well as removes the entire schema/structure of the table from the database. ...

Which is better TRUNCATE or DELETE?

Truncate removes all records and doesn't fire triggers. Truncate is faster compared to delete as it makes less use of the transaction log. Truncate is not possible when a table is referenced by a Foreign Key or tables are used in replication or with indexed views.

Is truncate a DDL command?

Although TRUNCATE TABLE is similar to DELETE , it is classified as a DDL statement rather than a DML statement. ... Truncate operations drop and re-create the table, which is much faster than deleting rows one by one, particularly for large tables. Truncate operations cause an implicit commit, and so cannot be rolled back.

Which is faster DROP or TRUNCATE?

TRUNCATE is a DDL(Data Definition Language) command. ... Like the DROP command, the TRUNCATE command also does not contain a WHERE clause. The TRUNCATE command is faster than both the DROP and the DELETE command. Like the DROP command we also can't rollback the data after using the this command.

What's the difference between truncate and delete in SQL?

• Key Differences Between DELETE and TRUNCATE in SQL. The main difference between DELETE and TRUNCATE is that using DELETE you can delete specified tuple from a relation. But the use of TRUNCATE will delete entire tuples from a relation. DELETE is DML command whereas, TRUNCATE is DDL command.

How do I empty a table in SQL?

• Select the database from the left menu. Select a table from the list in the left menu or in the center box. Select Drop from the center row of the table you want to delete. Drop is SQL-speak for delete. Confirm in the popup box that appears.

How do I delete rows from a table in SQL?

• Follow the given steps to delete a row or column by table menu: Place insertion point in row or column which you want to delete. After clicking on Table menu, select “Delete”. You will see a submenu of Delete being displayed in front of you. To delete selected row or column from the table, select Columns or Rows or Cells command.

What are some SQL commands?

• The commands are CREATE, ALTER, DROP, RENAME, and TRUNCATE. Data Manipulation Language (DML) - These SQL commands are used for storing, retrieving, modifying, and deleting data. These Data Manipulation Language commands are: SELECT, INSERT, UPDATE, and DELETE.