Reset identity seed after deleting records in SQL Server

Example:

The DBCC CHECKIDENT management command is used to reset identity counter.
The command syntax is:

DBCC CHECKIDENT (table_name [, { NORESEED | { RESEED [, new_reseed_value ]}}])
[ WITH NO_INFOMSGS ]

Reset Identity
Example:

DBCC CHECKIDENT ('transactionhead', RESEED, 0);

To Check current identity value
Example:

DBCC CHECKIDENT(transactionhead)