wgu c175 vocab Questions And Answers Rated 100% Correct!!

E-R Model - It is well named, as it diagrams entities (together with their attributes) and the relationship among them. Describe the ER model for "A salesperson works in one office." - What is the name of this relationship? exists when two entities are associated/relationship - Ex. A professor teaches many classes. - - One-to-one binary relationship Describe the ER model for "A salesperson sells to many customers." - What is the name of this relationship? It means that a single occurrence of one entity type can be associated with a single occurrence of the other entity type and vice versa. - - One-to-many binary relationship Describe the ER model for "(L to R) A salesperson is authorized to sell many products; (R to L) a product can be sold by many salespersons." - What is the name of this relationship? - - Many-to-many binary relationship What is the positioning and meaning for Cardinality and Modality on an ER model? - - Cardinality is the outer symbol; represents the maximum. - Modality is the inner symbol; represents the minimum. Describe the ER model for "(L to R) A salesperson works in a minimum of one and a maximum of one office, or exactly one office." "(R to L) An office may be occupied by or assigned to a minimum of no salespersons or a maximum of one salesperson." - Describe the ER model for "A salesperson may have no customers or many customers." - Describe the ER model for "(L to R) Each salesperson is authorized to sell to at least one or many of our products."and "(R to L) Each product can be sold by at least one or many of our salespersons." - Describe the ER model for "One salesperson backs-up another salesperson." - What is the name of this model? - - One-to-one unary relationship Describe the ER model for "(L to R) A salesperson manages zero to many other salespersons." and "(R to L) A salesperson is managed by exactly one other salesperson." - What is the name of this model? - - One-to-many unary relationship Describe the ER model for "(L to R) A product can be part of no other products or part of several other products." and "(R to L) A product can be composed of no other products or be composed of several other products." - What is the name of this model? - - Many-to-many unary relationship What does 'refer' in Referential Integrity imply? - - Referential integrity revolves around the circumstance of trying to refer to data in one relation in the database, based on values in another relation. Define the delete rule RESTRICT... - - If the delete rule between two relations is RESTRICT and an attempt is made to delete a record on the "one side" of the one-to-many relationship, the system will forbid the delete to take place if there are any matching foreign key values in the relation on the "many side". Define the delete rule CASCADE... - - If the delete rule between two relations is CASCADE and an attempt is made to delete a record on the "one side" of the relationship, not only will the record be deleted but all of the records on the "many side" of the relationship that have a matching foreign key value will also be deleted. - In other words, the delete will "cascade" from one relation to the other. Define the delete rule SET-TO-NULL... - - If the delete rule between the two relations is SETTO-NULL and an attempt is made to delete a record on the "one side" of the one-to-many relationship, that record will be deleted and the matching foreign key values in the records on the "many side" of the relationship will be set to null.Which entity is uniquely identified by concatenating the primary keys of the two entities it connects? - Associative entity