Deck 9: Joining Data From Multiple Tables

Question 1

The USING clause must be used with the JOIN keyword when linking tables that do not contain a commonly named column.​

Answer 1

False

Question 2

An outer join operator can be included in a FROM clause to list all rows from one table that do not have a corresponding row in the other table.​

Answer 2

False

Question 3

If a Cartesian join is used to link table A which contains two rows to table B which contains eight rows,there will be sixteen rows in the results.​

Answer 3

True

Question 4

​Data stored in multiple tables can be combined through the use of an ORDER BY clause.

Question 5

An outer join only lists rows that contain a match in both tables.​

Question 6

A table alias is assigned to a table in the WHERE clause.​

Question 7

Column qualifiers must be included in the WHERE clause if the columns used to join the tables have the same column names.​

Question 8

A Cartesian join usually results from the user omitting the joining condition that links two or more tables together.​

Question 9

The JOIN keyword is used in the WHERE clause to indicate the tables that should be joined or linked.

Question 10

The NATURAL JOIN keywords can be used to link two tables that have a commonly named and defined column.​

Question 11

When a self-join is created,each copy of the table must be assigned a table alias.​

Question 12

A column qualifier is used to indicate the table containing the column being referenced.​

Question 13

A column qualifier is separated from the column name with a colon.​

Question 14

If a Cartesian join is used to link table A which contains five rows to table B which contains eight rows,there will be 13 rows in the results.​

Question 15

A table alias can be assigned in the FROM clause,even when tables are being joined using the NATURAL JOIN keywords.​

Question 16

The NATURAL JOIN keywords can be used to create non-equality joins.​

Question 17

Equality,non-equality,and self-joins are all categorized as inner joins.​

Question 18

An inequality join refers to a join that is used to link a table to a copy of itself.​

Question 19

The most common type of join is an equijoin,which joins two or more tables together based upon the tables having equivalent data values in a common column.​

Question 20

An outer join operator consists of a minus sign enclosed in parentheses, (-).​

Question 21

A(n)non-equality join is used when there are no equivalent rows of data in the tables that are being joined._________________________​

Question 22

The outer join operator is placed on the side of the joining condition that references the table containing the deficient rows._________________________​

Question 23

A(n)non-equality join is when a table is joined to itself._________________________​

Question 24

The outer join operator is used to combine the results of multiple SELECT statements._________________________​

Question 25

The UNION set operator will not suppress rows that are returned by both queries.​

Question 26

Tables can be joined in the FROM clause or the WHERE clause of a SELECT statement._________________________​

Question 27

A column qualifier indicates the column containing the data being referenced._________________________​

Question 28

The outer join operator is placed on the side of the comparison that is deficient or is missing the matching rows.​

Question 29

The number of joining conditions required to join tables is always one less than the number of tables being joined.​

Question 30

A(n)outer join can be created by not including a joining condition in a SELECT statement._________________________​

Question 31

By default,use of the JOIN keyword creates an inner join.​

Question 32

A full outer join can be created by including an outer join operator on both sides of the linking condition stated in the WHERE clause.​

Question 33

The JOIN keyword must be used in the WHERE clause of a SELECT statement._________________________​

Question 34

A(n)non-equality join is also known as an equijoin,inner join,or simple join._________________________​

Question 35

The INTERSECT set operator only displays the rows returned by both queries.​

Question 36

​The MINUS set operator is used to display rows that were uniquely returned by the first query in the set.

Question 37

Set operators are used to combine the results of multiple queries.​

Question 38

A cross join between two tables,containing four rows each,will display eight rows in its output._________________________​

Question 39

A Cartesian join can be created by not including a joining condition in the WHERE clause of a SELECT statement._________________________​

Question 40

A(n)Cartesian Join replicates each row from the first table with every row from the second table._________________________​

Question 41

Which of the following is used to create an outer join in a WHERE clause?​

A) ​FULL OUTER JOIN keywords
B) ​LEFT OUTER JOIN keywords
C) ​RIGHT OUTER JOIN keywords
D) ​outer join operator (+)

Question 42

If a table alias is assigned in the SELECT clause,it must be used any time the table is referenced in that SQL statement._________________________​

Question 43

In Oracle12c,tables can be linked through which clause(s)?​

A) ​SELECT
B) ​FROM
C) ​WHERE
D) ​both b and c

Question 44

The ON clause can be used only if the tables being joined have a common column with the same name._________________________​

Question 45

A table alias is assigned in the FROM clause._________________________​

Question 46

Which of the following types of joins refers to results consisting of each row from the first table being replicated from every row in the second table?​

A) ​outer join
B) ​non-equality join
C) ​self-join
D) ​Cartesian join

Question 47

Equality,non-equality,and self-joins are broadly categorized as outer joins._________________________​

Question 48

When combining the results of two SELECT statements with the UNION keyword,duplicate rows are suppressed in the results._________________________​

Question 49

A(n)inner join will only include rows that have matching rows in the other table._________________________​

Question 50

Which of the following types of joins is created by matching equivalent values in each table?​

A) ​Cartesian join
B) ​equality join
C) ​non-equality join
D) ​outer join

Question 51

In a Cartesian join,linking a table that contains 10 rows to a table that contains 9 rows will result in ____ rows being displayed in the output.​

A) ​19
B) ​18
C) ​90
D) ​89

Question 52

​Which of the following keywords is used to create a Cartesian join?

A) ​OUTER JOIN
B) ​CROSS JOIN
C) ​NATURAL JOIN
D) ​JOIN...USING

Question 53

The JOIN...USING keywords are used to join two tables that do not have a commonly named and defined column._________________________​

Question 54

If you are joining five tables in a SELECT statement,five joining conditions will be required._________________________​

Question 55

If you are joining two tables in a SELECT statement,three joining conditions will be required._________________________​

Question 56

By default,the JOIN keyword creates an inner join._________________________

Question 57

When combining the results of two SELECT statements with the MINUS keyword,duplicate rows are suppressed in the results._________________________​

Question 58

​Which of the following types of joins refers to joining a table to itself?

A) ​Cartesian join
B) ​equality join
C) ​self-join
D) ​outer join

Question 59

The JOIN keyword is included in which of the following clauses?​

A) ​SELECT
B) ​FROM
C) ​WHERE
D) ​ORDER BY

Question 60

If you are joining four tables in a SELECT statement,three joining conditions will be required._________________________​

Question 61

If you are attempting to join two tables that have multiple common columns,which of the following JOIN keywords should be used to specify how the tables should be linked?​

A) ​OUTER JOIN
B) ​CROSS JOIN
C) ​JOIN...USING
D) ​none of the above

Question 62

Which of the following terms refers to a column with equivalent data that exists in two or more tables?​

A) ​common column
B) ​equiv-column
C) ​inner columns
D) ​simple columns

Question 63

​In which of the following examples is the ORDERS table used as a column qualifier?

A) ​o.order#
B) ​orders.order#
C) ​order#.o
D) ​order#.orders

Question 64

Which of the following set operators will display only the unique results of the combined SQL statements?​

A) ​UNION
B) ​UNION ALL
C) ​INTERSECT
D) ​MINUS

Question 65

​Which of the following set operators will display the results of the combined SQL statements without suppressing duplicate rows?

A) ​UNION
B) ​UNION ALL
C) ​INTERSECT
D) ​MINUS

Question 66

​
Structure of the ORDERS table
Structure of the CUSTOMERS table
​
Which of the following SQL statements will display all customers who have not recently placed an order?​

A) ​SELECT customer# FROM customers
UNION
SELECT customer# FROM orders;
B) ​SELECT customer# FROM orders
MINUS
SELECT customer# FROM customers;
C) ​SELECT customer# FROM orders
INTERSECT
SELECT customer# FROM customers;
D) ​SELECT customer# FROM customers
MINUS
SELECT customer# FROM orders;

Question 67

A table alias cannot be assigned in the FROM clause if which of the following keywords is used to join tables?​

A) ​NATURAL JOIN
B) ​JOIN...ON
C) ​LEFT OUTER JOIN
D) ​FULL OUTER JOIN

Question 68

​A table alias can consist of a maximum of ____ characters.

A) ​12
B) ​225
C) ​255
D) ​30

Question 69

​A join based upon a column from each table containing equivalent data is known as a(n)____.

A) ​inequality join
B) ​outer join
C) ​equality join
D) ​all of the above

Question 70

​The outer join operator in the WHERE clause cannot be used with which of the following operators?

A) ​IN
B) ​OR
C) ​AND
D) ​both a and b

Question 71

​
Structure of the ORDERS table
Structure of the CUSTOMERS table
​
​Which of the following SQL statements will return the names of all customers who placed an order on April 12,2003?

A) SELECT lastname,firstname
FROM customers
WHERE orderdate = '12-APR-03';
B) SELECT lastname,firstname
FROM customers NATURAL JOIN orders
WHERE orderdate = '12-APR-03';
C) SELECT lastname,firstname
FROM customers JOIN orders ON (customer#)
WHERE orderdate = '12-APR-03';
D) ​both a and b

Question 72

​A(n)____ is used to combine the results of two queries.

A) ​concatenation operator
B) ​set operator
C) ​comparison operator
D) ​logical operator

Question 73

​
Structure of the ORDERS table
Structure of the CUSTOMERS table
​
Which of the following SQL statements will list the name of each customer stored in the customers table,and,if the customer has placed an order that is contained in the ORDERS table,the order# of any order each customer has placed?​

A) SELECT lastname,firstname,order#
FROM orders RIGHT OUTER JOIN customers
USING (customer#);
B) SELECT lastname,firstname,order#
FROM orders LEFT OUTER JOIN customers
USING (customer#);
C) SELECT lastname,firstname,order#
FROM orders FULL OUTER JOIN customers
USING (customer#);
D) ​both a and c

Question 74

​Which of the following set operators can be used to make certain that only the rows returned by both queries are displayed in the results?

A) ​UNION
B) ​UNION ALL
C) ​INTERSECT
D) ​MINUS

Question 75

​
Structure of the ORDERS table
Structure of the CUSTOMERS table
​
​Which of the following queries will display data from both the ORDERS and CUSTOMERS tables?

A) ​SELECT * FROM orders,customers;
B) SELECT lastname,firstname,order#
FROM orders NATURAL JOIN customers;
C) SELECT lastname,firstname,order#
FROM orders,customers
WHERE orders.customer# = customers.customer#;
D) ​all of the above

Question 76

​Which of the following can only be used to link tables that have a common column?

A) ​FULL OUTER JOIN
B) ​JOIN...ON
C) ​NATURAL JOIN
D) ​CROSS JOIN

Question 77

​Which of the following keywords can be used to join two tables that do not contain a commonly named and defined column?

A) ​NATURAL JOIN
B) ​JOIN...ON
C) ​JOIN...USING
D) ​none of the above

Question 78

​Which of the following keywords is used to create an equality join?

A) ​NATURAL JOIN
B) ​JOIN...ON
C) ​JOIN...USING
D) ​all of the above

Question 79

​A column qualifier is separated from the column using which symbol?

A) ​comma (,)
B) ​plus sign (+)
C) ​period (. )
D) ​percent sign (%)

Question 80

​
Structure of the ORDERS table
Structure of the CUSTOMERS table
​
​Which of the following SQL statements will list the name of each customer stored in the CUSTOMERS table,and,if the customer has placed an order that is contained in the ORDERS table,the order# of any order each customer has placed?

A) SELECT lastname,firstname,order#
FROM customers NATURAL JOIN orders
WHERE orders.customer# IS NOT NULL;
B) SELECT lastname,firstname,order#
FROM customers,orders
WHERE orders.customer# (+)= customers.customer#;
C) SELECT lastname,firstname,order#
FROM customers,orders
WHERE orders.customer# = customers.customer# (+);
D) SELECT lastname,firstname,order#
FROM customers NATURAL JOIN orders
WHERE orders.customer# IS NULL;