A ____ relationship exists when an association is maintained within asingle entity.Select one:a.unaryb.ternaryc.binaryd.weakThe correct answer is:unary Show
Which of the following should be a derived attribute?Select one: Get answer to your question and much more A ____ attribute can be further subdivided to yield additional attributes.Select one: Get answer to your question and much more Upload your study docs or become a Course Hero member to access this document Upload your study docs or become a Course Hero member to access this document Specify for the following attributes if they are required attributes (REQ) or optional attributes (OPT) by writing REQ or OPT in the table below: ATTRIBUTE.....VALUES........REQ/OPT power.....Hybrid, Plug-in Hybrid, ...[power] = OPT
unary relationship Which relationship exists when two entities are associated?Calculate the Price
When the PK of one entity does not contain the PK of a related entity the relationship is?A weak or non-identifying relationship exists between two entities when the primary key of one of the related entities does not contain a primary key component of the other related entities. A strong or identifying relationship is when the primary key of the related entity contains the primary key of the “parent”. Which attributes can have several values? 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 of the following is an example for multi valued 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 attribute?Types of Attributes-
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. What is a key attribute?A key attribute is the unique characteristic of the entity. For ex. Name and hire date are attributes of the entity Employee. What type of attribute is age? Example: Class, Section, Age, Name etc, are the non-key attributes. Note: The same attribute can be of more than one kind. For Example, The Address attribute is a composite attribute, multivalued attribute, stored attribute and a non-key attribute. What is the difference between a composite attribute and a multi valued attribute? Multivalued A multivalued attribute may have one or more values for a particular entity. A typical example of a composite attribute is a person’s address, which is composed of atomic attributes, such as City, Zip, and Street. What is an attribute in a pattern?The concept of a pattern comes in many different forms. Attributes are characteristics that are used to describe an object. Color and shape are more concrete examples of pattern, which can be easily seen and manipulated. What is a single valued attribute?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 single value?A single-valued function is function that, for each point in the domain, has a unique value in the range. It is therefore one-to-one or many-to-one. A single-valued complex function of a complex variable is a complex function that has the same value at every point. What attribute Cannot be subdivided? Attributes that cannot be subdivided are called simple attributes. First Name and Last Name are now simple attributes. Most attributes have only a single value and as such are called single valued attributes. What type of attribute is gender? 2. Binary Attributes: Binary data has only 2 values/states. For Example yes or no, affected or unaffected, true or false. Symmetric: Both values are equally important (Gender). How many attribute types are there?five What is the difference between symmetric and asymmetric attributes?A binary variable is symmetric if both of its states are equally valuable, that is, there is no preference on which outcome should be coded as 1. A binary variable is asymmetric if the outcome of the states are not equally important, such as positive or negative outcomes of a disease test. What is the difference between nominal and numerical attribute?Nominal data is classified without a natural order or rank, whereas ordinal data has a predetermined or natural order. On the other hand, numerical or quantitative data will always be a number that can be measured. What is a nominal attribute? Nominal means “relating to names.” The values of a nominal attribute are symbols or names of things. Each value represents some kind of category, code, or state, and so nominal attributes are also referred to as categorical. The values do not have any meaningful order. What is relationship called when an association is maintained within a single entity?Unary relationship: Association is maintained within a single entity. Recursive relationship: Relationship exists between occurrences of the same entity set. Binary relationship: Two entities are associated.
What do you call a relationship between the instances of a single entity?Unary relationship (recursive)
A unary relationship, also called recursive, is one in which a relationship exists between occurrences of the same entity set. In this relationship, the primary and foreign keys are the same, but they represent two entities with different roles.
What is a relationship called when it is maintained between two entities select one?What is a relationship called when it is maintained between two entities? Explanation: Binary word usually represents two attributes. 7.
What are the relationships between entities?In a relational database a relationship between entities is implemented by storing the primary key of one entity as a pointer or "foreign key" in the table of another entity. There is a tradition for ER/data models to be built at two or three levels of abstraction.
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What is a relationship is called when an association is maintained between single entity?
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