What does truncate do in MySQL?

What does truncate do in MySQL?

TRUNCATE TABLE empties a table completely. It requires the DROP privilege. Logically, TRUNCATE TABLE is similar to a DELETE statement that deletes all rows, or a sequence of DROP TABLE and CREATE TABLE statements. To achieve high performance, TRUNCATE TABLE bypasses the DML method of deleting data.

How do I truncate a MySQL database?

Use the following procedure to perform the truncate table operation using the MySQL CLI:

  1. Log in to your hosting account using SSH: mysql -u [username] -p [database_name) For example: mysql -u johndoe -p data_mysite.
  2. Enter your password.
  3. Execute: truncate table [table_name]

How do I truncate a view in MySQL?

MySQL TRUNCATE TABLE

  1. TRUNCATE [TABLE] table_name;
  2. CREATE TABLE books ( id INT AUTO_INCREMENT PRIMARY KEY, title VARCHAR(255) NOT NULL ) ENGINE=INNODB;
  3. CALL load_book_data(10000);
  4. SELECT * FROM books;
  5. TRUNCATE TABLE books;

How do I truncate all tables in MySQL?

How to truncate all tables in MySQL?

  1. SET FOREIGN_KEY_CHECKS=0;
  2. SELECT TABLE_NAME FROM information_schema.
  3. TRUNCATE TABLE table1; TRUNCATE TABLE table2; TRUNCATE TABLE table3;
  4. SELECT Concat(‘TRUNCATE TABLE ‘, TABLE_NAME) FROM INFORMATION_SCHEMA.
  5. SET FOREIGN_KEY_CHECKS=1;

What is truncate in SQL with example?

The SQL TRUNCATE TABLE command is used to delete complete data from an existing table. You can also use DROP TABLE command to delete complete table but it would remove complete table structure form the database and you would need to re-create this table once again if you wish you store some data.

What is the function of truncate?

The TRUNCATE() function truncates a number to the specified number of decimal places.

How do I truncate a row 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.

What is difference between delete and truncate in MySQL?

Delete and truncate both commands can be used to delete data of the table. Delete is a DML command whereas truncate is DDL command. Truncate can be used to delete the entire data of the table without maintaining the integrity of the table. On the other hand , delete statement can be used for deleting the specific data.

How do you truncate a database?

To truncate a table, one must drop the foreign key constraints mapped to the columns in this table from other tables (in fact on all tables in the specific DB/Schema). So, all foreign key constraints must be dropped initially followed by table truncation.

Why we use truncate in SQL?

What is difference between truncate and delete?

The DELETE statement removes rows one at a time and records an entry in the transaction log for each deleted row. TRUNCATE TABLE removes the data by deallocating the data pages used to store the table data and records only the page deallocations in the transaction log. DELETE command is slower than TRUNCATE command.

What is truncate in database?

What is difference between delete and truncate in SQL?

The DELETE statement removes rows one at a time and records an entry in the transaction log for each deleted row. TRUNCATE TABLE removes the data by deallocating the data pages used to store the table data and records only the page deallocations in the transaction log.

How do you TRUNCATE data?

To remove all data from an existing table, use the SQL TRUNCATE TABLE order. You can also use the DROP TABLE command to delete an entire table. But Truncate will remove the entire table structure from the database, and you will need to recreate the table if you want to store any data.

How do you TRUNCATE?

To truncate a number, we miss off digits past a certain point in the number, filling-in zeros if necessary to make the truncated number approximately the same size as the original number. To truncate a number to 1 decimal place, miss off all the digits after the first decimal place.

Why we use TRUNCATE in SQL?

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.

How do you truncate in SQL?

What is the use of truncate in MySQL?

MySQL TRUNCATE () Function 1 Definition and Usage. The TRUNCATE () function truncates a number to the specified number of decimal places. 2 Syntax 3 Parameter Values 4 Technical Details. From MySQL 4.0 5 More Examples

How to truncate a number to a specific number in MySQL?

MySQL also provides us with the TRUNCATE () function. It is used to truncate a number to the specified number of decimal places. For instance, if we have a number say 15.236 and we want to truncate to only two decimal places, then TRUNCATE () would return 15.23.

What is the difference between delete and truncate in SQL?

Logically, the TRUNCATE TABLE statement is like a DELETE statement without a WHERE clause that deletes all rows from a table, or a sequence of DROP TABLE and CREATE TABLE statements. However, the TRUNCATE TABLE statement is more efficient than the DELETE statement because it drops and recreates the table instead of deleting rows one by one.

What is the difference between the TRUNCATE TABLE and DROP TABLE statements?

The TRUNCATE TABLE statement deletes all the records of a specified table. Unlike DROP TABLE statement this statement retains the structure of the table, it just removes all the records from the table.