When it comes to deleting data in SQL, there are several options available. The two most popular methods are the DELETE and TRUNCATE TABLE commands. Both of these commands can be used to remove data from a table, but they have some key differences that make them better suited for different scenarios. The DELETE statement deletes the rows one at a time and records one entry in the transaction log for each deleted row.
This makes it slower than the TRUNCATE TABLE command, which deletes all records and does not activate triggers. TRUNCATE is faster because it uses less of the transaction log. However, it is not possible to use TRUNCATE when a foreign key references a table, or when tables are used in replication or with indexed views. Another difference between the two operations is that if the table contains an identity column, the counter for that column is reset to 1 (or to the initial value defined for the column) in TRUNCATE. Additionally, rows deleted by the TRUNCATE TABLE statement cannot be restored and the WHERE clause cannot be specified in the TRUNCATE statement. If you have data that you don't want in a developing table, it's usually best to truncate it, since you don't run the risk of filling up the transaction log.
However, if you need to delete specific data, then DELETE is your best option. With DELETE, you can also bypass integrity compliance mechanisms. In summary, if you want to quickly delete all the rows in a table and you're sure you want to do it, then TRUNCATE is your best option. However, if you need to delete specific data or have foreign keys in your tables, then DELETE is your best bet.