DECLARE @TableName varchar(255)
DECLARE @MaxID INT

set @TableName = 'Categories'

SELECT @MaxID = MAX(category_id)
FROM categories
DBCC CHECKIDENT(@TableName, RESEED, @MaxID)
GO

http://blog.sqlauthority.com/2009/04/01/sql-server-reseed-identity-of-table-table-missing-identity-values-gap-in-identity-column/

Re-seed identity table if rows were deleted/there are gaps in numerical order

Re-seed Identity Table

sql

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