Chapter 6 Relational Databases and SQL TRUE FALSE 1 An entity in an accounting system can be classified as a resource event agent or location 2 A field is an item of data that characterizes an entity or relationship 3 Attributes that consist of multiple subattributes are referred to as primary attributes 4 A key attribute is the attribute whose value is unique for every entity that will appear in the database 5 The customer street address is often used as the key attribute in an REA diagram 6 In an REA diagram the rectangle is used to represent the composite attribute 7 The first step in REA is evaluating the attributes 8 Relationships define and map the way in which data can be extracted from a database in the future 9 A recursive relationship is a relationship between two different instances of an entity 10 The DBMS approach yields data redundancies when a supervisor is supervised by a third employee 11 A recursive relationship is created when there is an employee being supervised and another employee is the supervisor ANS T 12 Cardinality constraints relate to the specification of how many occurrences of an entity can participate in a given relationship with any one occurrence of the other entity in the relationship ANS T ANS F ANS F ANS T ANS F ANS F ANS F ANS T ANS T ANS F 13 The cardinality constraint is used to specify both the minimum and maximum participation of one entity in the relationship with the other entity 14 The notation 1 N is used to specify the relationship type of one to many 15 The notation of 1 1 is used to specify the relationship type of one to many 16 REA stands for resources entities and agents 17 The fundamental requirement for moving toward an event driven model is the complete integration of data related to an organization s business events 18 Enterprise systems are integrated software packages designed to provide complete integration of an organization s business information processing systems and all related data 19 A collection of data representing multiple occurrences of an object event or agent is known as a 20 A set of data that describes an instance of the entity represented by a relation is known as a tuple 21 A missing value is called a non null 22 The secondary key is specified to identity each tuple in the relation 23 SQL is a powerful database language that can be used to define database systems query the database for information generate reports from the database and access databases from within programs using embedded commands ANS T ANS F ANS T ANS F ANS F ANS T ANS T relation ANS T ANS T ANS F ANS F ANS T 24 Referential integrity specifies that for every attribute in one relation that has been specified to allow reference to another relation the tuple being referenced must be intact 25 A relation in an ER model is the same as an entity in the REA model 26 Most DBMS programs today that include SQL also include mechanisms within the DBMS itself for enforcing referential integrity 27 The INSERT command is used to add a single tuple to an existing relation 28 The UPDATE command demonstrates one of the weaknesses in most forms of SQL 29 The DELETE command is used when we want to change one or more attribute values ANS T ANS F ANS T ANS T ANS F ANS F ANS T 30 Queries of a database are driven by SELECT commands MULTIPLE CHOICE 1 An entity can be classified as all of the following except a b c d a b c d a b c d resource event tuple agent ANS C agent composite attribute attribute instance ANS D agent composite attribute attribute instance 2 A n of an entity is anything in which we are interested that exists independently 3 A n is an item of data that characterizes an entity or relationship 6 Which of the following is an attribute but least likely to be the key attribute 4 Which of the following is the entity or agent 5 Which of the following is the key attribute ANS C client client number client name client street address ANS A client client number client name client street address ANS B client client number client name client street address ANS D client client number client name client street address ANS D table attribute tuple row ANS B a b c d a b c d a b c d a b c d a b c d 7 Which of the following is a subattribute 8 A data field in a traditional file is similar to a relational 9 For the following entity and attribute model what would be the key attribute of the Students entity 10 A key attribute is the attribute whose value is social security number a b name c d address street ANS A a undeterminable b unique large c the same for all attributes d ANS B context diagram logical DFD a b c physical DFD d REA Model ANS D 11 The mapping of the relationships between entities would be used in the development of a n 12 The sequence of steps in identifying relationships in a model is a b c d evaluate entities as pairs identify user existing and desired information evaluate each entity to determine if there is any need for two occurrences of the same entity type to be linked identify user existing and desired information evaluate entities as pairs evaluate each entity to determine if there is any need for two occurrences of the same entity type to be linked evaluate entities as pairs evaluate each entity to determine if there is any need for two occurrences of the same entity type to be linked identify user existing and desired information evaluate each entity to determine if there is any need for two occurrences of the same entity type to be linked evaluate entities as pairs identify user existing and desired information ANS B 13 A recursive relationship is a relationship a between two similar entities of the same entity types b between two similar entities of different entity types c between two different entities of the same entity types d between two different entities of different entity types 14 Which of the following is not a relationship type 15 Which relationship type does 1 N mean ANS C a one to many b one to one c one to few d many to many ANS C a one to many b one to one c one to few d many to many ANS A ANS D a 1 1 b 1 N c N M d N 1 ANS B 16 The cardinality constraint of a relationship relates to a b c d specifying the minimum participation of one entity in the relationship specifying the maximum participation of one entity in the relationship the specification of how many occurrences of a relationship can participate in the given relationship with any one occurrence of the other relationship in the entity …