- Create table for a relationship.
- Add the primary keys of all participating Entities as fields of table with their respective data types.
- If relationship has any attribute, add each attribute as field of table.
How do we transform a multivalued attribute into table?
Rule: To convert a multivalued attribute in an ER diagram
How do you solve a multivalued attribute?
The only way to handle multiple values of the same attribute is
to create an entity in which you can store multiple instances, one for each value of the attribute
(for example, Figure 5-9).
Can a multivalued attribute be a primary key?
Multivalued attributes cannot work as primary keys
. Actually, multivalued attributes violate First Normal Form. So the good idea is to create a separate table and push multivalued attribute into it.
Can a multivalued attribute be composite?
Some Composite keys can
also be a multivalued attribute. For example, the address attribute of a student can further be divided into ‘Locality’, ‘Town’ and ‘PIN’. So, we call it a composite attribute. Also, the address of a student can have more than one value.
What is a multivalued attribute example?
A multivalued attribute of an entity is an attribute that can have more than one value associated with the key of the entity. For example,
a large company could have many divisions
, some of them possibly in different cities.
Which field is suitable as a multivalued attribute?
A multivalued attribute can have more than one value at a time for an attribute. For ex., the skills of a surgeon is a multivalued attribute since a surgeon can have more than one skill. Another common example is the
address field
, which can have multiple values like zipcode, street address, state, etc.
What are the types of attributes?
Attributes can also be subdivided into another set of attributes. There are five such types of attributes:
Simple, Composite, Single-valued, Multi-valued, and Derived attribute
.
What is a single valued attribute?
Attributes that can have single value at a particular instance of time
are called single valued. A person can’t have more than one age value. Therefore, age of a person is a single-values attribute.
What is attribute example?
An example of attribute is
to explain a person’s constant coughing as a result of chain smoking
. Attribute is defined as a quality or characteristic of a person, place or thing. Intelligence, charm and a sense of humor are each an example of an attribute.
What is a calculated attribute?
A Calculated Attribute (CA) is
a read-only value about a single user, providing granular insight into user behavior
. These attributes are defined in mParticle and are computed automatically over time by using the raw data stream of events and user information.
What is a simple attribute?
Simple attribute − Simple attributes
are atomic values, which cannot be divided further
. For example, a student’s phone number is an atomic value of 10 digits. Composite attribute − Composite attributes are made of more than one simple attribute. For example, a student’s complete name may have first_name and last_name.
Which of the following can be multivalued attribute?
Which of the following can be a multivalued attribute? Explanation:
Name and Date_of_birth cannot hold more than 1 value
.
Which of the following attributes can be a multivalued attribute?
A multivalued attribute can
have more than one value at a time for an attribute
. For ex., the skills of a surgeon is a multivalued attribute since a surgeon can have more than one skill. Another common example is the address field, which can have multiple values like zipcode, street address, state, etc.
Can an attribute have an attribute?
Some attributes can have
multiple values for
a given entity. For example, a customer could provide several telephone numbers, so the telephone number attribute is multivalued. Attributes help distinguish one entity from other entities of the same type.
