Most Common interview question in SQL

What is difference between DELETE and TRUNCATE commands?

Delete command removes the rows from a table based on the condition
that we provide with a WHERE clause. Truncate will actually remove all
the rows from a table and there will be no data in the table after we
run the truncate command.

TRUNCATE:

TRUNCATE is faster and uses fewer system and transaction log resources
than DELETE.

TRUNCATE removes the data by deallocating the data pages used to store
the table's data, and only the page deallocations are recorded in the
transaction log.

TRUNCATE removes all rows from a table, but the table structure, its
columns, constraints, indexes and so on, remains. The counter used by
an identity for new rows is reset to the seed for the column.

You cannot use TRUNCATE TABLE on a table referenced by a FOREIGN KEY
constraint.
Because TRUNCATE TABLE is not logged, it cannot activate a trigger.

TRUNCATE cannot be rolled back.

TRUNCATE is DDL Command.

TRUNCATE Resets identity of the table

DELETE:

DELETE removes rows one at a time and records an entry in the
transaction log for each deleted row.

If you want to retain the identity counter, use DELETE instead. If you
want to remove table definition and its data, use the DROP TABLE
statement.

DELETE Can be used with or without a WHERE clause

DELETE Activates Triggers.

DELETE can be rolled back.

DELETE is DML Command.

DELETE does not reset identity of the table.