SQL Server set two primary keys



First, a table cannot have two primary keys. However, there are two fields that can be combined into a single primary key, which is why there are sometimes two fields in the table that have the primary key flag, because they are grouped into a primary key.
We can first remove the original key and then use the TSQL to build
ALTER TABLE tablename ADD constraint Pk_name primary key (Colname1,colname2)

Or, in the Table Designer, hold down CTRL and select the two columns you want to set the primary key and then set the primary key to OK.

SQL Server set two primary keys