Frage 1
Frage
1) An ERM is dependent on the database type.
Frage 2
Frage
2) The word “entity” in the ER model corresponds to a table.
Frage 3
Frage
3) The Crow’s Foot model is less implementation-oriented than the Chen model.
Frage 4
Frage
4) The ER diagram represents the conceptual database as viewed by the end user.
Frage 5
Frage
5) The ER model refers to a specific table row as an entity instance.
Frage 6
Frage
6) In both the Chen and Crow’s Foot models, an entity is represented with a rectangle containing the entity’s name.
Frage 7
Frage
7) The ER model refers to a specific table row as an entity occurrence.
Frage 8
Frage
8) Attributes are types of entities.
Frage 9
Frage
9) In the original Chen model, each attribute is represented using an oval with the
attribute name connected to the entity with a line.
Frage 10
Frage
10. Software vendors have adopted the Chen representation because of its compact
representation.
Frage 11
Frage
11) Attributes have a domain that specifies the data type of the attribute.
Frage 12
Frage
12) Attributes cannot share a domain.
Frage 13
Frage
13) In an ER diagram, primary keys are usually bolded.
Frage 14
Frage
14. Ideally, a primary key is composed of several attributes.
Frage 15
Frage
15. A composite identifier is a primary key composed of more than one attribute.
Frage 16
Frage
16. All attributes are either simple or composite.
Frage 17
Frage
17) All simple attributes are also single-valued.
Frage 18
Frage
18) In the Chen model, a multivalued attribute is connected to the owning entity
with a double line.
Frage 19
Frage
19) The DBMS can easily handle multivalued attributes.
Frage 20
Frage
20) Derived attributes are stored in a special database table.
Frage 21
Frage
21) A relationship is identified by a name that describes the relationship.
Frage 22
Frage
22) Cardinality expresses the minimum and maximum number of entity occurrences associated with one occurrence of the related entity.
Frage 23
Frage
23) In Chen notation, there is no way to represent cardinality.
Frage 24
Frage
24) Connectivities and cardinalities are established by business rules.
Frage 25
Frage
25) A weak relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity.
Frage 26
Frage
26) You should always load data from the 1 side of a 1:M relationship.
Frage 27
Frage
27) A weak entity has a primary key that is partially or totally derived from the parent entity in the relationship
Frage 28
Frage
28. The existence of a mandatory relationship indicates that the minimum cardinality is 0 or 1 for the mandatory entity.
Frage 29
Frage
29) Relationships operate only in one direction.
Frage 30
Frage
30. A recursive relationship is one in which a relationship can exist between occurrences of the same entity set