It activates the triggers on the table and causes them to fire The TRUNCATE statement does not delete the table structure but resets the identity of the table The DELETE statement deletes the records and does not interfere with the table's identity. For an InnoDB table, InnoDB processes TRUNCATE TABLE by deleting rows one by one if there are any FOREIGN KEY constraints that reference the table. You cannot restore the deleted data after executing this command. You can restore the data using the COMMIT or ROLLBACK command. It records only the deleted data pages in the transaction log. It records all the deleted data rows in the transaction log.
Its speed is fast as it only records data pages in transaction logs. Its speed is slow as it makes operations in rows and records it in transaction logs TRUNCATE operates on data pages and executes deletion of the whole table data at a time. The TRUNCATE command requires fewer locks and resources before deleting the data page because it acquires the lock on the data pageĭELETE operation operates on data records and executes deletion one-by-one on records in the order of the queries processed The DELETE command acquires the lock on every deleting record thus, it requires more locks and resources. The TRUNCATE command is used to delete the complete data from the table. The DELETE command is used to delete particular records from a table. The following table will help you understand the key difference between DELETE and TRUNCATE Commands. The Key Difference Between Delete and Truncate Now you will run the following SQL query to check the table structure.Īs you can see above, though the players’ table has been truncated, the table structure remains intact. This SQL query will remove all the records from the table. Here you will use the truncate command to delete all records from the table players. Let’s understand this with the help of an example. The syntax for the TRUNCATE command to remove data from the table: Execution of this command locks the pages instead of rows therefore, it requires fewer locks and resources. You cannot roll back the deleted data as it does not register the log during the execution of this operation.
You cannot use the WHERE clause with this command therefore, you cannot filter the records. It performs the same function as a DELETE statement without a WHERE clause. The Truncate statement is a DDL or Data Definition Language command that is used to delete the complete data from the table without deleting the table structure. The TRUNCATE TABLE statement is used to remove all records from a table in MySQL. with player_id = 106, from the players' table. TRUNCATE TABLE empties a table completely. The SQL query mentioned above will remove the last row, i.e. Now you must write a query to delete the last record with player_id = 106.ĭelete from players where player_id = 106 To Truncate Table use Execute SQL processor before ConvertJSONtoSQL processor. Insert into players (player_id, name, country, goals) I am reading CSV files from an SFTP site and loading it to mysql db. You will create a table named players and insert a few records on the table.Ĭreate table players (player_id int, name varchar(20), Now, understand this with the help of an example. Therefore, you should have a database backup before executing this command.īelow is the syntax for the DELETE command to remove data from the table: This example would truncate the table called products in the database called totn.After executing this command, you cannot recover the deleted records. Let's look at one more example where we prefix the table name with the database name.įor example: TRUNCATE TABLE totn.products The main difference between the two is that you can roll back the DELETE statement if you choose, but you can't roll back the TRUNCATE TABLE statement. It would be equivalent to the following DELETE statement in MySQL: DELETE FROM customers īoth of these statements would result in all data from the customers table being deleted. This example would truncate the table called customers and remove all records from that table.
Mysql truncate table how to#
Let's look at an example of how to use the TRUNCATE TABLE statement in MySQL. In most cases, MySQL handles the process of table truncation a bit differently than other databases such as Oracle or SQL Server. In MySQL, truncating a table is a fast way to clear out records from a table if you don't need to worry about rolling back.
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