BCIS 4620 CH 7

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

"old-style" join

How many rows would be returned from a cross join of tables A and B, if A contains 8 rows and B contains 18?

144

Which comparison operator indicates a value is not equal?

<>

The special operator used to check whether an attribute value is within a range of values is _____.

BETWEEN

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

COMMIT

The SQL aggregate function that gives the number of rows containing non-null values for a given column is _____.

COUNT

The _____ function returns the current system date in MS Access.

DATE()

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.

DECODE

The _____ command defines a default value for a column when no value is given.

DEFAULT

_____ is a relational set operator.

EXCEPT

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

EXISTS

All SQL commands must be issued on a single line.

False

An alias cannot be used when a table is required to be joined to itself in a recursive query.

False

Comparison operators cannot be used to place restrictions on character-based attributes.

False

Most SQL implementations yield case-insensitive searches.

False

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

False

SQL is considered difficult to learn; its command set has a vocabulary of more than 300 words

False

The COMMIT command does not permanently save all changes. In order to do that, you must use SAVE.

False

You cannot insert a row containing a null attribute value using SQL.

False

The _____ command restricts the selection of grouped rows based on a condition.

HAVING

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.

JOIN ON

_____ is a string function that returns the number of characters in a string value.

LENGTH

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

LIKE

When using the Oracle TO_DATE function, the code _____ represents a three-letter month name.

MON

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

Operations within parantheses

A(n) _____ query specifies which data should be retrieved and how it should be filtered, aggregated, and displayed.

SELECT

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 UNIQUE V_CODE FROM PRODUCT;

The syntax for a left outer join is _____.

SELECT column-list FROM table1 LEFT [OUTER] JOIN table2 ON join-condition

In Oracle, the _____ function converts a date to a character string.

TO_CHAR()

Date procedures are often more software-specific than other SQL procedures.

TRUE

The ANSI SQL standards are also accepted by the ISO.

TRUE

Which is a feature of a correlated subquery?

The outer subquery initiates the process of execution in a subquery.

A database language enables the user to perform complex queries designed to transform the raw data into useful information.

True

ANSI-standard SQL allows the use of special operators in conjunction with the WHERE clause.

True

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.

True

Numeric functions take one numeric parameter and return one value

True

Numeric functions take one numeric parameter and return one value.

True

SQL allows the use of logical restrictions on its inquiries such as OR, AND, and NOT.

True

Some RDBMSs, such as Microsoft Access, automatically make the necessary conversions to eliminate case sensitivity.

True

String comparisons are made from left to right.

True

The COUNT function is designed to tally the number of non-null "values" of an attribute, and is often used in conjunction with the DISTINCT clause.

True

The conditional LIKE must be used in conjunction with wildcard characters.

True

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

True

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

alias

A(n) _____ join performs a relational product (also known as the Cartesian product) of two tables.

cross

When using a(n) _____ join, only rows from the tables that match on a common value are returned.

inner

A(n) _____ join will select only the rows with matching values in the common attribute(s).

natural

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.

outer

In subquery terminology, the first query in the SQL statement is known as the _____ query.

outer

The SQL data manipulation command HAVING:

restricts the selection of grouped rows based on a condition.

A(n) _____ is a query that is embedded (or nested) inside another query.

subquery