Question

There are ten entries in the table and primary key id is set to autoincrement. If I delete all entries and insert one more its id will be 11, is it possible to reset ids to 1 again?

Answer 1

Try truncate table command like below :

TRUNCATE TABLE tablename

it will reset auto increment id to 1.

If your table is refrenced with other table using foreign key then you can enable/disable contraint using below commands :

To Enable constraint:

EXEC sp_msforeachtable @command1="print '?'", 
                       @command2="ALTER TABLE ? WITH CHECK CHECK CONSTRAINT all";

To Disable constraint:

EXEC sp_msforeachtable "ALTER TABLE ? NOCHECK CONSTRAINT all";