SQL Server – How to Uniquely identify a row?

Without seeing the table structure,If you are interested in knowing which columns uniquely identify a row in a table, you can use this system procedure

Consider the following table

create table #testing(id int primary key, emp_name varchar(100))

Note that the column named id is unique by default. Now execute the following system procedure sp_special_columns

EXEC tempdb..sp_special_columns '#testing'

The result is as shown below