Mid Term 2 Intro To Database
In the ERD, cardinality is indicated using the ____ notation.
(min,max)
The special operator used to check whether an attribute value is within a range of values is ____.
BETWEEN
The ____ attribute(s) make up the primary key in the table definition:CLASS (CRS_CODE, CLASS_SECTION, CLASS_TIME, CLASS_ROOM, PROF_NUM)
CLASS_SECTION
The following step occurs first in the process of building an ERD: ____.
Create a detailed narrative of the organization's description of operations.
To delete a row from the PRODUCT table, use the ____ command.
DELETE
The ____ command is used with the ALTER TABLE command to modify the table by deleting a column.
DROP
Only numeric data types can be added and subtracted in SQL.
F
The SQL command that lets you insert rows into a table is ____.
INSERT
The special operator used to check for similar character strings is ____.
LIKE
Which query will use the given columns and column aliases from the PRODUCT table to determine the total value of inventory held on hand and display the results in a column labeled TOTVALUE?
Question options: SELECT P_DESCRIPT, P_QOH, P_PRICE, P_QOH*P_PRICE AS TOTVALUEFROM PRODUCT;
The ____ command is used to restore the table's contents to their previous values.
ROLLBACK;
The SQL command that lets you select attributes from rows in one or more tables is ____.
SELECT
Which of the following is used to select partial table contents?
SELECT <column(s)> FROM <Table name> WHERE <Conditions>;
Which query is used to list a unique value for V_CODE, where the list will produce only a list of those values that are different from one another?
SELECT DISTINCT V_CODE FROM PRODUCT;
The query used to list the P_CODE, P_DESCRIPT, P_INDATE, and P_PRICE fields from the PRODUCT table in ascending order by P_PRICE is ____.
SELECT P_CODE, P_DESCRIPT, P_INDATE, P_PRICE FROM PRODUCT ORDER BY P_PRICE;
Which query will output the table contents when the value of the character field P_CODE is alphabetically less than 1558-QW1?
SELECT P_CODE, P_DESCRIPT, P_QOH, P_MIN, P_PRICEFROM PRODUCTWHERE P_CODE <'1558-QW1';
Which query will output the table contents when the value of V_CODE is not equal to 21344?
SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODEFROM PRODUCTWHERE V_CODE <> 21344;
The query to join the P_DESCRIPT and P_PRICE fields from the PRODUCT table and the V_NAME, V_AREACODE, V_PHONE, and V_CONTACT fields from the VENDOR table where the values of V_CODE match is ____.
SELECT P_DESCRIPT, P_PRICE, V_NAME, V_CONTACT, V_AREACODE, V_PHONE FROM PRODUCT, VENDOR WHERE PRODUCT.V_CODE = VENDOR.V_CODE;
Which query will use the given columns and column aliases from the PRODUCT table to determine the total value of inventory held on hand?
SELECT P_DESCRIPT, P_QOH, P_PRICE, P_QOH*P_PRICE FROM PRODUCT;
UPDATE tablename ***** [WHERE conditionlist]; The ____ command replaces the ***** in the syntax of the UPDATE command, shown above.
SET columnname = expression
The most recent fully approved version of standard SQL prescribed by the ANSI is ____.
SQL-99
The SQL aggregate function that gives the total of all values for a selected attribute in a given column is ____.
SUM
A ____ relationship exists when two entities are associated.
binary
____ relationships are most common.
binary
The associative entity is also known as a ____ entity.
composite
The ERD represents the ____ database as viewed by the end user.
conceptual
The set of possible values for an attribute is a ____.
domain
A relationship is an association between ____.
entities
If an entity can exist apart from one or more related entities, it is said to be ____-independent.
existence
Any changes made to the contents of a table are not physically saved on disk until you use the SAVE <table name> command.
f
In an ER diagram, primary keys are usually bolded.
f
Information implies familiarity, awareness, and understanding knowledge as it applies to an environment.
f
One advantage of a database system over previous data management approaches is that the database system is considerably less complex.
f
Oracle users can use the Access QBE (query by example) query generator.
f
Referential and entity integrity are two names for the same thing.
f
SQL is considered difficult to learn; its command set has a vocabulary of more than 300 words.
f
The ANSI prescribes a standard SQL-the current fully approved version is known as SQL-07.
f
The CHECK constraint is used to define a condition for the values that the attribute domain cannot have.
f
The existence of a mandatory relationship indicates that the minimum cardinality is 0 or 1 for the mandatory entity.
f
The idea of determination is unique to the database environment.
f
The one-to-many (1:M) relationship is easily implemented in the relational model by putting the foreign key of the "1" side in the table of the "many" side as a primary key.
f
The order of the rows and columns is important to the DBMS.
f
The relational model is hardware-dependent and software-independent.
f
There is never a good reason to use null values in a database.
f
To join tables, simply enumerate the tables in the FROM clause of the SELECT statement. The DBMS will create a Cartesian product of every table in the FROM clause. To get the correct results, you need to select the rows in which the common attribute values do not match.
f
You cannot insert a row containing a null attribute value using SQL.
f
A ____ is a character or group of characters that has a specific meaning.
field
VMS/VSAM is an example of a(n) ____.
file system data model
A derived attribute ____.
has many values
____ attributes can have many values.
miltivalued
Ideally, an entity identifier is composed of ____ attribute(s).
one
Some attributes are classified as ____.
simple
A ____ attribute can have only one value.
single-valued
A(n) ____ is a query that is embedded (or nested) inside another query.
subquery
A database language enables the user to create database and table structures to perform basic data management chores.
t
Although SQL commands can be grouped together on a single line, complex command sequences are best shown on separate lines, with space between the SQL command and the command's components.
t
SQL allows the use of logical restrictions on its inquiries such as OR, AND, and NOT.
t
Some RDBMSs, such as Microsoft Access, automatically make the necessary conversions to eliminate case sensitivity.
t
String comparisons are made from left to right.
t
The conditional LIKE must be used in conjunction with wildcard characters.
t
A ____ entity has a primary key that is partially or totally derived from the parent entity in the relationship.
weak
When the PK of one entity does not contain the PK of a related entity, the relationship is ____.
weak
The ____ relationship should be rare in any relational database design.
1:1
Which of the following is an example of structured data?
A spreadsheet
The ____ serve(s) as the intermediary between the user and the database.
DBMS
Data and information are essentially the same thing.
F
____ yields only the rows that appear in both tables.
INTERSECT
____ is used to reveal the meaning of data.
Information
____ data can have only a true or false (yes or no) values.
Logical
Codd's Rule of ____ states:Application programs and ad hoc facilities are logically unaffected when changes are made to the table structures that preserve the original table values (changing order of columns or inserting columns).
Logical Data Independence
To be considered minimally relational, the DBMS must support the key relational operators ____, PROJECT, and JOIN.
SELECT
____ combines all rows from two tables, excluding duplicate rows.
UNION
____ data exist in a format that does not lend itself to processing that yields information.
Unstructured
____ is a set of tools that work together to provide an advanced data analysis environment for retrieving, processing, and modeling data from the data warehouse.
XML processing
A(n) ____ might be written by a programmer or it might be created through a DBMS utility program.
application program
A(n) ____ is the equivalent of a field in a file system.
attribute
Another name for a composite entity is a ____ entity.
bridge
A ____ key can be described as a superkey without unnecessary attributes, that is, a minimal superkey.
candidate
A(n) ____ model represents a global view of the database as viewed by the entire organization.
conceptual
A(n) ____ is a restriction placed on the data.
constraint
____ are normally expressed in the form of rules.
constraints
A(n) ____ enables a database administrator to define schema components.
data definition language (DDL)
The phrase ____ refers to an organization of components that define and regulate the collection, storage, management and use of data within a database environment.
database system
In the context of a database table, the statement "A ____ B" indicates that if you know the value of attribute A, you can look up the value of attribute B.
determines
A(n) ____ database is used by an organization and supports many users across many departments.
enterprise
A CUSTOMER table's primary key is CUS_CODE. The CUSTOMER primary key column has no null entries, and all entries are unique. This is an example of ____ integrity.
entity
A noun in a business rule translates to a(n) ____ in the data model.
entity
The ____ model uses the term connectivity to label the relationship types.
entity relationship
The ____ model was developed to allow designers to use a graphical tool to examine structures rather than describing them with text.
entity relationship
A foreign key must exist in both tables that have a relationship.
f
A manager and a programmer usually have the same view of the same data.
f
A query language is a procedural language.
f
A weak relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity.
f
An ERM is dependent on the database type.
f
An operational database is sometimes referred to as an enterprise database.
f
Attributes are types of entities.
f
Attributes cannot share a domain.
f
Attributes have a domain that specifies the data type of the attribute.
f
Business rules apply to businesses and government groups, but not to other types of organizations such as religious groups or research laboratories.
f
Character data can contain any character or symbol intended for mathematical manipulation.
f
Database programming languages receive all application requests and translate them into the complex operations required to fulfill those requests.
f
Derived attributes are stored in a special database table.
f
End-user interfaces require the end user to manually generate SQL code.
f
In Chen notation, there is no way to represent cardinality.
f
In the ____ model, each parent can have many children, but each child has only one parent.
hierarchical
One of the limitations of the ____ model is that there is a lack of standards.
hierarchical
A(n) ____ join only returns matched records from the tables that are being joined.
inner
The organization of the data within the folders in a manual file system was determined by ____.
its expected use
A(n) ____'s main function is to help you understand the complexities of the real-world environment.
model
A(n) ____ join links tables by selecting only the rows with common values in their common attribute(s).
natural
No data entry at all is known as a(n) ____.
null
____ logic, used extensively in mathematics, provides a framework in which an assertion (statement of fact) can be verified as either true or false.
predicate
Since it is used to link the tables that originally were related in a M:N relationship, the composite entity structure includes—as foreign keys—at least the ____ keys of the tables that are to be linked.
primary
End-user data is ____.
raw facts of interest to the end-user
Controlled ____ makes a relational database work.
redundancy
MySQL is an example of a(n) ____.
relational data model
A verb associating two nouns in a business rule translates to a(n) ____ in the data model.
relationship
XML data is ____.
semistructured
A desktop database is a ____ database.
single-user
A ____ is any key that uniquely identifies each row.
superkey
In a database context, a(n) ____ indicates the use of different names to describe the same attribute.
synonym
The ____ is actually a system-created database whose tables store the user/designer-created database characteristics and contents.
system catalog
A data dictionary contains metadata—data about data.
t
A data model is usually graphical.
t
A data warehouse can store data derived from many sources.
t
A left outer join on tables CUSTOMER and AGENT yields all of the rows in the CUSTOMER table, including those that do not have a matching value in the AGENT table.
t
A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind.
t
A recursive relationship is one in which a relationship can exist between occurrences of the same entity set
t
All attributes are either simple or composite.
t
Connectivities and cardinalities are established by business rules.
t
DBMSs use indexes for many different purposes.
t
Each row in the relational table is known as an entity instance or entity occurrence in the ER model.
t
If the attribute (B) is functionally dependent on a composite key (A) but not on any subset of that composite key, the attribute (B) is fully functionally dependent on (A).
t
In an SQL-based relational database, rows in different tables are related based on common values in common attributes.
t
In both the Chen and Crow's Foot models, an entity is represented with a rectangle containing the entity's name.
t
In the Chen model, a multivalued attribute is connected to the owning entity with a double line.
t
Initially the files within a computer file system were similar to manual files.
t
Metadata present a more complete picture of the data in the database than the data itself.
t
Tables must have the same attribute characteristics (the columns and domains must be compatible) to be used in a UNION.
t
The DIVIDE operation uses one single-column table (e.g., column "a") as the divisor and one two-column table (e.g., columns "a" and "b") as the dividend.
t
The ER diagram represents the conceptual database as viewed by the end user.
t
The entity relationship model is limited to conceptual modeling, with no implementation component.
t
The practical significance of taking the logical view of a database is that it serves as a reminder of the simple file concept of data storage.
t
The same data might be simultaneously structured and unstructured depending on the intended processing.
t
They can serve as a communication tool between the users and designers.
t
Today, most relational database products can be classified as object/relational.
t
Within the database environment, a data model represents data structures with the purpose of supporting a specific problem domain.
t
A(n) ____ is perceived as a two-dimensional structure composed of rows and columns.
table
A(n) ____ database is designed to support a company's day-to-day operations.
transactional
A(n) ____ database is used by an organization and supports many users across many departments.
workgroup
