Modern Database Management - Self Check 06

The ________ clause sorts the final results rows of a query in ascending or descending order

ORDER BY

A database table is defined using the data definition language (DDL

T

The content of dynamic views is generated when they are referenced.

T

A ________ is a virtual table that is created dynamically upon request to a user.

dynamic view

The DROP TABLE command causes tables to be ________, ________, and ________ from the database.

removed, deleted, dropped

When using an expression in SQL, expressions inside the

Parenthesis

The content of dynamic views is generated when they are referenced

T

The comparison operators ________ and ________ are used to establish a range of values in SQL

<, >

The ________ command enables one to change table definitions.

ALTER TABLE

The ________ contains raw data

base table

Using aggregate functions will give a ________ answer

one-row

Every SELECT statement returns a ________ when it executes

result table

The ________ Boolean operator joins two or more conditions and returns results only when all conditions are true

AND

The ON UPDATE ________option allows changes to a parent table to pass onto a child table or tables.

CASCADE

SQL command defines a logical table from one or more tables

CREATE VIEW

A(n) ________ is a set of schemas put together that represent a database description

Catalog

Adding the keyword ________ to an SQL query will eliminate duplicate rows from the query result set

Distinct

A catalog is the structure that contains object descriptions created by a user.

F

A database is maintained and queried using the data mapping language (DML)

F

A referential integrity constraint specifies that the existence of an attribute in one table depends upon the existence of a foreign key in the same or another table

F

A single value returned from an SQL query that includes an aggregate function is called a vector aggregate

F

Count(*) tallies only those rows that contain a value, while Count counts all rows

F

DCL is used to update the database with new records

F

DCL is used to update the database with new records.

F

Implementation of a standard can never stifle creativity and innovation

F

Indexes generally slow down access speed in most RDMS

F

Materialized views are stored on disk and are never refreshed

F

SQL has been implemented only in the mainframe and midrange environments

F

SQL originated from a project called System-S

F

The CREATE SCHEMA DDL command is used to create a table

F

The DELETE TABLE DDL command is used to remove a table from the database

F

The DROP command deletes rows from a table individually or in groups.

F

The HAVING clause and the WHERE clause perform the same operation

F

The ORDER BY clause is the first statement processed in an SQL command

F

The comparison operators = and != are used to establish a range of values

F

The following query totals sales in state= 'MA' for each salesperson. Select salesperson_id, sum(sales) from salesperson group by salesperson_id having state = 'MA';

F

The following two SQL statements will produce different results. Select last_name, first_name from customer where state = 'MA' or state = 'NY' or state = 'NJ' or state = 'NH' or state = 'CT'; Select last_name, first_name from customer where state in ('MA','NY','NJ','NH','CT');

F

When creating a table, it is not important to consider foreign keyprimary key mates

F

When the select clause in the create view statement contains the keyword DISTINCT, the view can be used to update data

F

is a constraint that specifies that the value of an attribute in one relation depends upon the value of a primary key in the same or other relation

Referential integrity

The ________ SQL command lists the columns from base tables or views to be projected into the command result table

SELECT

In SQL the ________ and ________ clauses are required, while the ________ clause is needed when only certain rows are to be retrieved or multiple tables are to be joined.

SELECT; FROM; WHERE

A major benefit of SQL as a standard is reduced training costs

T

Adding the DISTINCT keyword to a query eliminates duplicates

T

Applications can be moved from one machine to another when each machine uses SQL

T

Expressions are mathematical

T

If multiple boolean operators are used in an SQL statement, NOT is evaluated first, then AND, then OR

T

In order to update data in SQL, one must inform the DBMS which relation, columns, and rows are involved

T

One of the original purposes of the SQL standard was to provide a vehicle for portability of database definition and application modules between conforming DBMSs

T

SQL is both an American and international standard for database access

T

Some DBMS can handle graphic data types, as well as text and numbers

T

The ALTER TABLE command is used to change a table definition

T

The FROM clause is the first statement processed in an SQL command

T

The ORDER BY clause sorts the final results rows in ascending or descending order

T

The SQL command used to populate tables is the INSERT command

T

The WHERE clause includes the conditions for row selection within a single table or view, and the conditions between tables or views for joining

T

The WHERE clause is always processed before the GROUP BY clause when both occur in a SELECT statement.

T

The asterisk (*) wildcard designator can be used to select all fields from a table, as well as in WHERE clauses when an exact match is not possible

T

The following query totals sales for each salesperson. Select salesperson_id, sum(sales) from salesperson group by salesperson_id;

T

The following two SQL statements will produce the same results. Select last_name, first_name from customer where credit_limit > 99 and credit_limit < 10001; Select last_name, first_name from customer where credit_limit between 100 and 10000;

T

When a GROUP BY clause is included in an SQL statement, only those columns with a single value for each group can be included'True

T

When creating tables, it's important to decide which columns will allow null values before the table is created

T

The HAVING clause acts as a secondary ________ clause

WHERE

The ________ is a set of commands used to define a database

data definition language

The ________ is a set of commands used to define a database

data manipulation language

Indexes are created in most RDBMS to provide rapid ________ and ________ access to base-table data

random; sequential

To update data in SQL we must inform the DBMS what ________, ________, and ________ are involved

relation, columns, rows

A DBMS that manages data as a collection of tables in which all data relationships are represented by common values in related tables is called a(n) ________ DBMS.

relational

The structure that contains descriptions of objects created by a user, such as base tables and views is called a(n) ________

schema