it 214
Enter the SQL command to add the database named COLLEGE.
CREATE DATABASE COLLEGE;
Write the complete SQL command to add a new databse HAPPY_LEARNING
CREATE DATABASE HAPPY_LEARNING;
A student has many advisors and a advisor advises many students.
MANY to MANY
Enter the SQL command to show all the data in the table department.
SELECT * FROM DEPARTMENT;
The attribute that cannot be divided in simpler parts that have a different semantic meaning in the real world, is known as:
Simple Attribute
Which is the name of the command to mark the specified database as the current database for the following operations?
USE
For which of the following attributes, entity instances mus have the same values for the attribute?
not unique attributes
"CREATE DATABASE gmu;" command is used to create a new SQL database gmu. It will give an error if gmu already exists.
right
A required attribute must have a value in it and cannot be left blank
right
"ADD DATABASE " command is used to create a new SQL database.
wrong
Given a multi-value attribute, with two values, for which we need to process independently the values, but without performing global processing on all the values, it is recommended to consider a new dependent entity to represent the values.
wrong
Enter the complete SQL command to create a SQL database named GMU if there is no such database:
CREATE DATABASE IF NOT EXISTS GMU;
Complete the command name which is used to create SQL database:
CREATE DATABSE
Enter the SQL command to show the structure of the created table department.
DESCRIBE DEPARTMENT;
Enter the complete SQL command to delete a SQL database named GMU, giving an error if there is no such database:
DROP DATABASE GMU;
Enter the complete SQL command to delete a SQL database named GMU, not giving an error if there is no such database:
DROP DATABASE IF EXISTS GMU;
Given the following entity: EMPLOYEE(FIRST_NAME, MIDDLE_NAME, LAST_NAME, EMAIL, PHONE, DOB, ADDRESS), keeping contact information about employees in a company. Which is a possible primary key?
Given the following entity: EMPLOYEE(ID, FIRST_NAME, MIDDLE_NAME, LAST_NAME, EMAIL, PHONE, DOB, ADDRESS), keeping contact information about employees in a company. Which is a possible primary key?
ID
Enter the beginning of the SQL command to add data to an entity with the name COURSE.
INSERT INTO COURSE VALUES
Specification: A student is enrolled in many classes.
MANY to MANY
A student has one advisor but an advisor advises many students.
MANY to ONE
The following command is used to generate a table with all defined SQL databases:
SHOW DATABASES;
Enter the SQL command to mark the database named COLLEGE as the default database in the current session.
USE COLLEGE;
The command below is used to mark the database named GMU as the current database for the following operations:
USE GMU;
Write the complete SQL command to make the database HAPPY_LEARNING the default database.
USE HAPPY LEARNING;
A functional dependency is a relation between attributes.
right
For the entity PERSON the attribute fullname is not an example of a duplicated values attribute.
wrong
Given a bridge with two attributes, it is usually recommended to create a surrogate key for the bridge.
wrong
Given and entity that has only candidate keyes with 4 or more attributes, it is not recommended to create a surrogate key for the entity.
wrong
"CREATE DATABASE" command is used to create a new SQL database.
right
"First name" of a person can be defined as an example of "not-unique" attribute.
right
A binary relationship exists when two entities are associated.
right
A database is an organized collection of data.
right
A database organized in terms of the relational model is a relational database.
right
A duplicated attribute is an attribute that may have the same value for two entity instances.
right
A foreign key is a field(or collection of fields) in one table that uniquely identifies a row of another table or the same table.
right
A primary key containing two or more attributes is named composite primary key.
right
A primary key is a field in a table which uniquely identifies each entity instance (row) n a database.
right
A relationship in ER model captures how entities are related to one another.
right
A simple attribute is an attribute that cannot be divided in simpler parts that have a different semantic meaning in the real world.
right
A simple primary key is composed of a single attribute
right
A single-valued attribute is an attribute that has at most a single value for any given entity instance.
right
A strong relationship is known as identifying relationship
right
A subtype discriminator is the attribute in the super type entity that determines to which subtype the supertype occurrence is related.
right
A subtype discriminator is the attribute in the supertype entity that determines to which subtype the supertype occurrence is related.
right
A table in unnormalized (unf) form has either repeating groups, composite data cells, multi-value data cells or lacks a valid primary key.
right
A table is in first normal for if it has a proper primary key, all data cells have a single elementary value and have repeating groups.
right
A table is in first normal form if it has a proper primary key, all data cells have single elementary value and does not have repeating groups.
right
A unary relationship exists when an association is maintained within a single entity.
right
A unique attribute is an attribute that have a unique value or no value at all for all entity instances.
right
A(n) multi-valued attribute has two or more value for some entity instances.
right
A(n) required attribute is an attribute that must have a value fro all entity instances.
right
An alias for a table is defined in the FROM clause using the reserved word AS
right
An entity has a distinct existence as an individual unit.
right
Crow's foot notation depicts a weak relationship by placing a dashed line between the entities.
right
Database normalization is the process of modifying the structure of a database based on a sequence of normal forms, from first normal form to a higher level normal form.
right
Entities in ER model must be named using a consistent case notation.
right
Entity cardinality in a relationship expresses the minimum and maximum number of entity instances occurrences associated with one entity instance occurrence of the related entity.
right
For a relationship between a PARENT_ENTITY and CHILD_ENTITY the general template for an inner join, with the joining condition in the WHERE clause is: SELECT ... FROM PARENT_ENTITY, CHILD ENTITY WHERE PARENT_ENTITY.ID=CHILD_ENTITY.PARENT_ID AND .....;
right
For the entity PERSON the attribute address is an example of a composite attribute.
right
For the entity PERSON the attribute first_name is not an example of an optional attribute.
right
For the entity PERSON the attribute name is an example of a composite attribute.
right
Given a multi-value attribute with a variable number of value , for which we need to process independently the values, it is recommended to consider a new dependent entity to represent the values.
right
Given an entity with a set of related attributes describing one of its characteristic, having a lot of duplicated tuples. For instance, for cars at a dealer it is stored the interior and exterior color. In this situation it is not recommended to consider a new entity describing these attributes.
right
In relational databases, a transitive dependency exists if an only if there is an attrubute or set of attributes Y such that X determines Y and Y determines Z.
right
Information resolves uncertainty and represents processed data.
right
Partial completeness is symbolized by a circle over a single line.
right
RDB is the notation for a relational database.
right
Relationships names are verbs, linking two or more nouns
right
SQL is the abbreviation for Structured Query Language.
right
Structured Query Language (SQL) enables users to create a database objects and manipulate and view data.
right
Structured Query Language (SQL) is a fourth generation language.
right
The abbreviation for database is DB.
right
The command INSERT INTO is used to add relationship data by specifying the correct values for the foreign keys into corresponding tables.
right
The completeness constraint specifies whether each entity supertype occurrence must also be a member of at least one subtype.
right
The completeness constraint specifies whether each subtype entity occurrence must also be member of at least on subtype.
right
The completeness constraint specifies whether each supertype entity occurrence must also be a member of at least one subtype.
right
The domain of an attribute may represent an entity itself.
right
The domain of attribute may represent and entity itself.
right
The emails of a person is an example of a multi-value attributes.
right
The name of the command to mark a database as the current database for the following operation is "USE".
right
the relational model represents data in tuples grouped in relations.
right
"CREATE DATABASE IF NOT EXISTS gmu;" command is used to create new SQL database named gmu, if there is not database already created. It will not give an error if gmu exists.
wrong
"CREATE DATABASE gmu;" command is used to create a new SQL database gmu. It will not give an error if gmu already exists.
wrong
"Middle name" of a person is not an example of optional attribute
wrong
A database is defined as any data stored and accessed on a computer system.
wrong
A database organized in terms of objects, their properties and the relations between them is a relational database.
wrong
A unary relationship exists when an association is made between the same entity instance.
wrong
An "optional" attribute must have a value in it and cannot be left blank.
wrong
Database normalization is the process of modifying the structure of a database based on a sequence of normal forms, from a current normal form to a lower level normal form. from first normal
wrong
Entity instances cannot have the same values for the "not unique" attribute.
wrong
For the entity PERSON the attribute first_name is an example of an optional attribute.
wrong
DELETE DATABASE command is used to delete a SQL database.
wrong DROP DATABASE is used
To implement a relationship in SQL we use the primary key constraint in CREATE TABLE command.
wrong we use the reference constraint instead
SELECT D.NAME, E.FIRST_NAME, E.LAST_NAME FROM DEPARTMENT CROSS JOIN EMPLOYEE will generate a list with all the department names and all the employees working in that department(with duplicates).
wrong will generate all the possible combinations between the department names and employee names(with duplicates).
SELECT D.NAME, E.FIRST_NAME, E.LAST_NAME FROM DEPARTMENT, EMPLOYEE will generate a list with all the department names and all the employees working in that department(with duplicates).
wrong will generate all the possible combinations between the department names and employee names(with duplicates).
