Greenville, South Carolina. For other uses, see Greenville. Greenville (/ËÉ¡riËnvÉªl/; locally /ËÉ¡riËnvÉl/) is the county seat of Greenville County in the upstate region of South Carolina, in the United States. The city's mayor is Knox White, who has served in that position since December 1995.
Non-key Attributes. back: surrogate key. next: derived attributes. Non-key attributes are attributes that are not part of a key. Generally, most attributes are simply descriptive, and fall into this category. Consider attributes for first name, last name, birth date; usually these attributes are non-key attributes.Consider a name attribute.on-key Attributes. back: surrogate key. next: derived attributes. Non-key attributes are attributes that are not part of a key. Generally, most attributes are simply descriptive, and fall into this category. Consider attributes for first name, last name, birth date; usually these attributes are non-key attributes.
ID attribute values must also be unique among all elements in the document. Duplicates aren't allowedeven if the element names are different. Think of an ID attribute as a primary key for a table but with the additional constraint that you can't use the key value in any other table in your database.