Deck 5: Multiple-Table Queries

Question 1

In small databases,there is a significant time difference between different query approaches.

Answer 1

False

Question 2

For two tables to be union compatible,the columns of the two tables must be identical.

Answer 2

False

Question 3

One reason for using an alias is when you are joining a table to itself.

Answer 3

True

Question 4

To relate two tables,in the FROM clause list all columns involved in the query.

Question 5

You can use the EXISTS operator to retrieve data from more than one table.

Question 6

There is only one approach to joining tables.

Question 7

You must join tables by finding rows in the two tables that have identical values in matching columns.

Question 8

In a nested query,the outer query is evaluated first.

Question 9

When joining tables,it is always necessary to qualify a column name.

Question 10

You can use the IN operator to retrieve data from multiple tables.

Question 11

You can join tables by using a condition in the WHERE clause.

Question 12

When the innermost subquery is evaluated,a permanent table is produced.

Question 13

One reason for using an alias is simplicity.

Question 14

You must use a comma or a period to separate a table name from its alias.

Question 15

You can join three tables together but not four tables.

Question 16

It is permissible to qualify all column names in a query.

Question 17

Occasionally,a self-join might involve the primary key of a table.

Question 18

Oracle supports the INTERSECT operator.

Question 19

To ensure that query results are listed in a desired order,use the ORDER BY clause.

Question 20

When using a DBMS without an optimizer,the formulation of a query can make a difference in the speed with which the query is executed.

Question 21

Table A has 10 rows and table B has 7 rows.The product of Table A and Table B would have 70 rows.

Question 22

You create an alias by typing the name of the table,pressing the ____,and then typing the name of the alias.​

A)Tab
B)​Backspace
C)Enter
D)​Spacebar

Question 23

The product operation is commonly used.

Question 24

To produce the same results as the MINUS operator,use NOT,the IN operator and a subquery.

Question 25

The ____ of two tables is the set of all rows that are in the first table but that are not in the second table.​

A)union
B)​intersect
C)intersection
D)​difference

Question 26

You can precede a subquery with the ____ operator to create a condition that is true if one or more rows are obtained when the subquery is executed.​

A)IS NULL
B)​IS TRUE
C)IS EXIST
D)​EXISTS

Question 27

To qualify a column name,precede the name of the column with the name of the table,followed by a(n)____.​

A)comma (,)
B)​period (.)
C)percent sign (%)
D)​asterisk (*)

Question 28

SQL Server does not support the MINUS operator.

Question 29

You can use the ALL and ANY operators with subqueries to produce a single column of numbers.

Question 30

To retrieve data from multiple tables in a query you can use the ____ operator with a subquery.​

A)AND
B)​IN
C)OR
D)​NOT

Question 31

The ____ of two tables is a table containing every row that is in either the first table,the second table,or both tables.​

A)intersection
B)​union
C)minus
D)​difference

Question 32

You can join tables by using a condition in the ____ clause.​

A)FROM
B)​WHERE
C)SELECT
D)​JOIN

Question 33

When a subquery involves a table listed in the outer query,the subquery is called a(n)____ subquery.​

A)inner outer
B)​correlated
C)reverse
D)​parameter

Question 34

There are three types of inner joins.

Question 35

In a full outer join,all rows from both tables will be included regardless of whether they match rows from the other table.

Question 36

A(n)____ clause can include statistics calculated for only the groups or columns whose values are identical for each row in a group.​

A)SELECT
B)​WHERE
C)FROM
D)​EXISTS

Question 37

The ____ of two tables is a table containing all rows that are in both tables.​

A)intersect
B)​union
C)difference
D)​minus

Question 38

It is easy to create a product inadvertently by omitting the WHERE clause when you are attempting to join tables.

Question 39

You can perform special operations,such as self-joins,within SQL.

Question 40

To produce the same results as the INTERSECT operator,use the BETWEEN operator and a subquery.

Question 41

Which of the following joins compares the tables in the FROM clause and lists only those rows that satisfy the condition in the WHERE clause?​

A)inner
B)​outer
C)nested
D)​product

Question 42

In a ____,all rows from the table on the right will be included regardless of whether they match rows from the table on the left.​

A)left inner join
B)​left outer join
C)right outer join
D)​right inner join

Question 43

SQL performs many built-in ____________________ that analyze queries to determine the best way to satisfy them.​

Question 44

The subquery that involves a table listed in the outer query is called a(n)____________________ subquery.​

Question 45

When tables are listed in the FROM clause,you can give each table a(n)____________________,or an alternate name.​

Question 46

Oracle and SQL Server support the ____ operator but Microsoft Access does not.​

A)UNION
B)​INTERSECT
C)MINUS
D)​ALL

Question 47

To retrieve data from more than one table,you must ____________________ the tables together by finding rows in the two tables that have identical values in matching columns.​

Question 48

You join tables in SQL by including a condition in the ____________________ clause to ensure that matching columns contain equal values.​

Question 49

In a(n)____ join,all rows from both tables are included regardless of whether they match rows from the other table.​

A)normal
B)​inner
C)full outer
D)​combined

Question 50

For an SQL implementation to truly support the union operation,it must remove ____ rows automatically.​

A)dependent
B)​no
C)independent
D)​duplicate

Question 51

In a ____,all rows from the table on the left (the table listed first in the query)will be included regardless of whether they match rows from the table on the right (the table listed second in the query).​

A)left inner join
B)​left outer join
C)right inner join
D)​right outer join

Question 52

Joining a table to itself is called a(n)____________________.​

Question 53

A subquery within a subquery is called a(n)____________________ subquery.​

Question 54

In a multiple-table query,you list all the desired columns in the ____________________ clause and qualify any columns that appear in more than one table.​

Question 55

Two tables are ____ compatible if they have the same number of columns and if their corresponding columns have identical data types and lengths.​

A)union
B)​minus
C)difference
D)​intersect

Question 56

If you had two separate tables for customers and the query requested customers in the first table having the same city as customers in the second table,you could use a normal ____________________ operation to find the answer.​

Question 57

When there is potential ambiguity in listing column names,you must ____________________ the columns involved in the query.​

Question 58

The product of two tables is formally called the ____ Product.​

A)Oracle
B)​Outer
C)SQL
D)​Cartesian

Question 59

If you precede the subquery by the ____ operator,the condition is true only if it satisfies any value (one or more)produced by the subquery.​

A)IS SOME
B)​IS ANY
C)SOME
D)​ANY

Question 60

If you precede the subquery by the ____ operator,the condition is true only if it satisfies all values produced by the subquery.​

A)TRUE
B)​ALL
C)IS ALL
D)​ALWAYS

Question 61

What steps should you take to construct the SQL command to join (relate)tables?​

Question 62

If you precede a subquery by the ____________________ operator,the condition is true only if it satisfies all values produced by the subquery.​

Question 63

The ____________________ of two tables is a table containing all rows that are in both tables.​

Question 64

If the SQL implementation truly supports the union operation,it will remove any duplicate ____________________ automatically.​

Question 65

Describe the types of outer joins.​

Question 66

The ____________________ of two tables is a table containing every row that is in either the first table,the second table,or both tables.​

Question 67

The ____________________ of two tables is the combination of all rows in the first table and all rows in the second table.​

Question 68

What steps should you take to construct a detailed query in a step-by-step fashion?​

Question 69

A join that compares the tables in the FROM clause and lists only those rows that satisfy the condition in the WHERE clause is called a(n)____________________ join.​

Question 70

There are three set operations: union,intersection,difference.Define each of these operations.Which are supported by Oracle?​

Question 71

Sometimes you need to list all the rows from one of the tables in a join,regardless of whether they match any rows in the other table.This type of join is called a(n)____________________ join.​

Question 72

If you precede a subquery by the ____________________ operator,the condition is true only if it satisfies one or more values produced by the subquery.​

Question 73

Why do you use the ANY and ALL operators? What is the difference between the two operators?​

Question 74

The ____________________ of two tables is the set of all rows that are in the first table but that are not in the second table.​

Question 75

Two tables are ____________________ compatible if they have the same number of columns and if their corresponding columns have identical data types and lengths.​