Chapter 7: Introduction to Structured Query Language (SQL)

The basic SQL vocabulary has fewer than _____words.

ANSWER: 100 one hundred a hundred

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

ANSWER: Boolean

_____ functions allow you to take a value of a given data type and convert it to the equivalent value in another data type.

ANSWER: Conversion

The _____ statement in SQL combines rows from two queries and returns only the rows that appear in the first set but not in the second.

ANSWER: EXCEPT

Rows can be grouped into smaller collections quickly and easily using the _____ clause within the SELECT statement.

ANSWER: GROUP BY

The _____ clause of the GROUP BY statement operates very much like the WHERE clause in the SELECT statement.

ANSWER: HAVING

The _____ operator could be used in place of INTERSECT if the DBMS does not support it.

ANSWER: IN

The _____ operator could be used in place of EXCEPT (MINUS) if the DBMS does not support it.

ANSWER: NOT IN

DATE() and SYSDATE are special functions that return today's date in MS Access and _____, respectively.

ANSWER: Oracle

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

ANSWER: SELECT

The _____ specification is used to avoid having duplicated values in a column.

ANSWER: UNIQUE

"_____" means that the names of the relation attributes must be the same and their data types must be alike.

ANSWER: Union-compatible

A(n) _____ is an alternate name given to a column or table in any SQL statement. a. alias b. data type c. stored function d. trigger

ANSWER: a

A(n) _____ join returns not only the rows matching the join condition (that is, rows with matching values in the common columns) but also the rows with unmatched values. a. outer b. inner c. equi- d. cross

ANSWER: a

A(n) _____ join will select only the rows with matching values in the common attribute(s). a. natural b. outer c. full d. cross

ANSWER: a

In subquery terminology, the first query in the SQL statement is known as the _____ query. a. outer b. left c. inner d. base

ANSWER: a

The SQL aggregate function that gives the number of rows containing non-null values for a given column is _____. a. COUNT b. MIN c. MAX d. SUM

ANSWER: a

The special operator used to check whether an attribute value is within a range of values is _____. a. BETWEEN b. NULL c. LIKE d. IN

ANSWER: a

When using the Oracle TO_DATE function, the code _____ represents a three-letter month name. a. MON b. MM3 c. MONTH d. MM

ANSWER: a

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? a. SELECT ONLY V_CODE FROM PRODUCT; b. SELECT UNIQUE V_CODE FROM PRODUCT; c. SELECT DIFFERENT V_CODE FROM PRODUCT; d. SELECT DISTINCT V_CODE FROM PRODUCT;

ANSWER: a

_____ is a relational set operator. a. EXCEPT b. PLUS c. ALL d. EXISTS

ANSWER: a

_____ is a string function that returns the number of characters in a string value. a. LENGTH b. SUBSTRING c. CONCAT d. UCASE

ANSWER: a

A(n) _____ join performs a relational product (also known as the Cartesian product) of two tables. a. full b. cross c. natural d. equi-

ANSWER: b

A(n) _____ query specifies which data should be retrieved and how it should be filtered, aggregated, and displayed. a. INSERT b. SELECT c. COMMIT d. UPDATE

ANSWER: b

The SQL data manipulation command HAVING: a. restricts the selection of rows based on a conditional expression. b. restricts the selection of grouped rows based on a condition. c. modifies an attribute's values in one or more table's rows. d. groups the selected rows based on one or more attributes.

ANSWER: b

The _____ command restricts the selection of grouped rows based on a condition. a. DISPLAY b. HAVING c. FROM d. CONVERT

ANSWER: b

The special operator used to check whether a subquery returns any rows is _____. a. BETWEEN b. EXISTS c. LIKE d. IN

ANSWER: b

The syntax for a left outer join is _____. a. SELECT column-list FROM table1 OUTER JOIN table2 LEFT WHERE join-condition b. SELECT column-list FROM table1 LEFT [OUTER] JOIN table2 ON join-condition c. SELECT column-list WHERE LEFT table1 = table d. SELECT column-list FROM table1 LEFT table2 [JOIN] WHERE join-condition

ANSWER: b

Which is a feature of a correlated subquery? a. The inner subquery executes first. b. The outer subquery initiates the process of execution in a subquery. c. The inner subquery initiates the process of execution in a subquery. d. The outer subquery executes independent of the inner subquery.

ANSWER: b

A(n) _____ is a query that is embedded (or nested) inside another query. a. alias b. operator c. subquery d. view

ANSWER: c

According to the rules of precedence, which of the following computations should be completed first? a. Additions and subtractions b. Multiplications and divisions c. Operations within parentheses d. Power operations

ANSWER: c

In Oracle, the _____ function converts a date to a character string. a. CONVERT() b. TO_DATE c. TO_CHAR() d. TO_STRING()

ANSWER: c

The Oracle _____ function compares an attribute or expression with a series of values and returns an associated value or a default value if no match is found. a. NVL b. TO_CHAR c. DECODE d. CONVERT

ANSWER: c

The SQL command that allows a user to permanently save data changes is _____. a. INSERT b. SELECT c. COMMIT d. UPDATE

ANSWER: c

The _____ function returns the current system date in MS Access. a. TO_DATE() b. SYSDATE() c. DATE() d. TODAY()

ANSWER: c

The special operator used to check whether an attribute value matches a given string pattern is _____. a. BETWEEN b. IS NULL c. LIKE d. IN

ANSWER: c

What type of command does this SQL statement use? SELECT P_CODE, P_DESCRIPT, P_PRICE_V_NAME FROM PRODUCT, VENDOR WHERE PRODUCT.V_CODE=VENDOR. V_CODE a. set operator b. natural join c. "old-style" join d. procedural statement

ANSWER: c

When using a(n) _____ join, only rows from the tables that match on a common value are returned. a. full b. outer c. inner d. set

ANSWER: c

A(n) _____ 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: cascading

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

ANSWER: conditional

How many rows would be returned from a cross join of tables A and B, if A contains 8 rows and B contains 18? a. 8 b. 18 c. 26 d. 144

ANSWER: d

If a designer wishes to create an inner join, but the two tables do not have a commonly named attribute, he can use a(n) _____ clause. a. OF b. USING c. HAS d. JOIN ON

ANSWER: d

The _____ command defines a default value for a column when no value is given. a. CHECK b. UNIQUE c. NOT NULL d. DEFAULT

ANSWER: d

Which comparison operator indicates a value is not equal? a. < b. <= c. >= d. <>

ANSWER: d

The _____ condition is generally composed of an equality comparison between the foreign key and the primary key of related tables.

ANSWER: join

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

ANSWER: query

The syntax of the EXCEPT statement in Oracle is _____.

ANSWER: query EXCEPT query;

An alias is especially useful when a table must be joined to itself in a(n) _____ query.

ANSWER: recursive

A(n) _____, also known as a nested query or an inner query, is a query that is embedded (or nested) inside another query.

ANSWER: subquery

A(n) _____ character is a symbol that can be used as a general substitute for other characters or commands.

ANSWER: wildcard wild card