Lesson 6

Question 1

alias

Answer 1

An alternative name for a column or table in a SQL statement.

Question 2

ALTER TABLE

Answer 2

The SQL command used to make changes to table structure. When the command is followed by a keyword (ADD or MODIFY), it adds a column or changes column characteristics.

Question 3

AND

Answer 3

The SQL logical operator used to link multiple conditional expressions in a WHERE or HAVING clause. It requires that all conditional expressions evaluate to true.

Question 4

AVG

Answer 4

A SQL aggregate function that outputs the mean average for a specified column or expression.

Question 5

BETWEEN

Answer 5

In SQL, a special comparison operator used to check whether a value is within a range of specified values.

Question 6

Boolean algebra

Answer 6

A branch of mathematics that uses the logical operators OR, AND, and NOT.

Question 7

cascading order sequence

Answer 7

A nested ordering sequence for a set of rows, such as a list in which all last names are alphabetically ordered and, within the last names, all first names are ordered.

Question 8

COMMIT

Answer 8

The SQL command that permanently writes data changes to a database.

Question 9

COUNT

Answer 9

A SQL aggregate function that outputs the number of rows containing not null values for a given column or expression, sometimes used in conjunction with the DISTINCT clause.

Question 10

CREATE INDEX

Answer 10

A SQL command that creates indexes on the basis of a selected attribute or attributes.

Question 11

CREATE TABLE

Answer 11

A SQL command that creates a table’s structures using the characteristics and attributes given.

Question 12

DELETE

Answer 12

A SQL command that allows data rows to be deleted from a table.

Question 13

DISTINCT

Answer 13

A SQL clause that produces only a list of values that are different from one another.

Question 14

DROP INDEX

Answer 14

A SQL command that permanently deletes an index.

Question 15

DROP TABLE

Answer 15

A SQL command that permanently deletes a table and its data.

Question 16

EXISTS

Answer 16

In SQL, a comparison operator that checks whether a subquery returns any rows.

Question 17

FROM

Answer 17

A SQL clause that specifies the table or tables from which data is to be retrieved.

Question 18

GROUP BY

Answer 18

A SQL clause used to create frequency distributions when combined with any of the aggregate functions in a SELECT statement.

Question 19

HAVING

Answer 19

A clause applied to the output of a GROUP BY operation to restrict selected rows.

Question 20

IN

Answer 20

In SQL, a comparison operator used to check whether a value is among a list of specified values.

Question 21

inner query

Answer 21

A query that is embedded or nested inside another query. Also known as a nested query or a subquery.

Question 22

INSERT

Answer 22

A SQL command that allows the insertion of one or more data rows into a table.

Question 23

IS NULL

Answer 23

In SQL, a comparison operator used to check whether an attribute has a value.

Question 24

LIKE

Answer 24

In SQL, a comparison operator used to check whether an attribute’s text value matches a specified string pattern.

Question 25

MAX

Answer 25

A SQL aggregate function that yields the maximum attribute value in a given column.

Question 26

MIN

Answer 26

A SQL aggregate function that yields the minimum attribute value in a given column.

Question 27

nested query

Answer 27

In SQL, a query that is embedded in another query.

Question 28

NOT

Answer 28

A SQL logical operator that negates a given predicate.

Question 29

OR

Answer 29

The SQL logical operator used to link multiple conditional expressions in a WHERE or HAVING clause. It requires only one of the conditional expressions to be true.

Question 30

ORDER BY

Answer 30

A SQL clause that is useful for ordering the output of a SELECT query (for example, in ascending or descending order).

Question 31

ROLLBACK

Answer 31

A SQL command that restores the database table contents to the condition that existed after the last COMMIT statement.

Question 32

rules of precedence

Answer 32

- Basic algebraic rules that specify the order in which operations are performed. - For example, operations within parentheses are executed first, so in the equation 2 + (3 * 5), the multiplication portion is calculated first, making the correct answer 17.

Question 33

subquery

Answer 33

A query that is embedded (or nested) inside another query. Also known as a nested query or an inner query.

Question 34

SUM

Answer 34

A SQL aggregate function that yields the sum of all values for a given column or expression.

Question 35

UPDATE

Answer 35

A SQL command that allows attribute values to be changed in one or more rows of a table.

Question 36

WHERE

Answer 36

A SQL clause that adds conditional restrictions to a SELECT statement that limit the rows returned by the query.

Question 37

wildcard character

Answer 37

A symbol that can be used as a general substitute for: (1) all columns in a table (*) when used in an attribute list of a SELECT statement or, (2) zero or more characters in a SQL LIKE clause condition ( % and _ ).

Question 38

SQL commands can be divided into two overall categories: _______ and ______ commands.

Answer 38

- Data definition languauge (DDL) | - Data manipulation language (DML)

Question 39

The basic DML commands are:

Answer 39

- SELECT - INSERT - UPDATE - DELETE - COMMIT - ROLLBACK

Question 40

The basic data definition commands allow you to create tables and indexes. Many SQL constraints can be used with columns. The commands are:

Answer 40

- CREATE TABLE - CREATE INDEX - ALTER TABLE - DROP TABLE - DROP INDEX

Question 41

The ANSI prescribes a standard SQL-the current fully approved version is known as SQL 07. (T/F)

Answer 41

False

Question 42

You can select partial table contents by naming the desired fields and by placing restrictions on the rows to be included in the output. (T/F)

Answer 42

True

Question 43

The ______ command, coupled with appropriate search conditions, is an incredibly powerful tool that enables a user to transform data into information.

Answer 43

SELECT

Question 44

The conditional LIKE should be used in conjunction with wildcard characters. (T/F)

Answer 44

True

Question 45

A database language enables the user to perform complex queries designed to transform the raw data into useful information. (T/F)

Answer 45

True

Question 46

The special operator used to check whether a subquery returns any rows is _____.

Answer 46

EXISTS

Question 47

According to the rules of precedence, which of the following computations should be completed first?

Answer 47

Performing operations within parentheses

Question 48

The SQL command that allows a user to permanently save data changes is _____.

Answer 48

COMMIT

Question 49

In SQL, all _______ expressions evaluate to true or false.

Answer 49

conditional or boolean

Question 50

A database language enables the user to create database and table structures to perform basic data management chores. (T/F)

Answer 50

True

Question 51

The SQL data manipulation command HAVING:

Answer 51

restricts the selection of grouped rows based on a condition.

Question 52

String comparisons are made from left to right. (T/F)

Answer 52

True

Question 53

To make the output more readable, the SQL standard permits the use of aliases for any column in a ______ statement.

Answer 53

SELECT

Question 54

Which operator is used to check whether an attribute value lies within two bounds?

Answer 54

BETWEEN

Question 55

The SQL command that allows a user to list the contents of a table is _____.

Answer 55

SELECT

Question 56

Date procedures are often more software-specific than other SQL procedures. (T/F)

Answer 56

True

Question 57

A _______ order sequence is a multilevel ordered sequence that can be created easily by listing several attributes, separated by commas, after the ORDER BY clause.

Answer 57

cascading

Question 58

Oracle users can use the Access QBE (query by example) query generator. (T/F)

Answer 58

False

Question 59

The _____ special operator is used to check whether an attribute value is null.

Answer 59

IS NULL

Question 60

SQL allows the use of logical restrictions on its inquiries such as OR, AND, and NOT. (T/F)

Answer 60

True

Question 61

ANSI-standard SQL allows the use of special operators in conjunction with the WHERE clause. (T/F)

Answer 61

True

Question 62

The basic SQL vocabulary has fewer than _____ words.

Answer 62

hundred

Question 63

The ANSI SQL standards are also accepted by the ISO. (T/F)

Answer 63

True

Question 64

SQL is considered difficult to learn; its command set has a vocabulary of more than 300 words. (T/F)

Answer 64

False

Question 65

Mathematical operators cannot be used to place restrictions on character-based attributes. (T/F)

Answer 65

False

Question 66

A specialty field in mathematics, known as ______ algebra, is dedicated to the use of logical operators.

Answer 66

Boolean

Question 67

A(n) _____ is an alternate name given to a column or table in any SQL statement.

Answer 67

alias

Question 68

The SQL command that allows a user to insert rows into a table is _____.

Answer 68

INSERT

Question 69

The special operator used to check whether an attribute value matches a given string pattern is _____.

Answer 69

LIKE

Question 70

Most SQL implementations yield case-insensitive searches. (T/F)

Answer 70

False

Question 71

Some RDBMSs, such as Microsoft Access, automatically make the necessary conversions to eliminate case sensitivity. (T/F)

Answer 71

True

Question 72

In the SQL environment, the word _____ covers both questions and actions.

Answer 72

query