check primary key of a table in SQL Server

Primary key check in table

 select ISNULL(i.is_primary_key,0) FROM  
    sys.columns c
INNER JOIN
    sys.types t ON c.user_type_id = t.user_type_id
LEFT OUTER JOIN
    sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
LEFT OUTER JOIN
    sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
WHERE
    c.object_id = OBJECT_ID(TABLENAME) AND ISNULL(i.is_primary_key,0) = 1


===>O/P:= 1