DROP SEQUENCE (Transact-SQL)
Removes a sequence object from the current database.
Applies to: SQL Server (SQL Server 2012 through current version).
After generating a number, a sequence object has no continuing relationship to the number it generated, so the sequence object can be dropped, even though the number generated is still in use.
A sequence object can be dropped while it is referenced by a stored procedure, or trigger, because it is not schema bound. A sequence object cannot be dropped if it is referenced as a default value in a table. The error message will list the object referencing the sequence.
To list all sequence objects in the database, execute the following statement.
SELECT sch.name + '.' + seq.name AS [Sequence schema and name] FROM sys.sequences AS seq JOIN sys.schemas AS sch ON seq.schema_id = sch.schema_id ; GO
The following example removes a sequence object named CountBy1 from the current database.
DROP SEQUENCE CountBy1 ; GO