True/False
Indicate whether the
statement is true or false.
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1.
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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.
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2.
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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.
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3.
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A Cartesian join usually results when the programmer omits the joining condition
that links two or more tables together.
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4.
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An outer join lists all rows that contain a match in both tables.
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5.
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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.
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6.
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An outer join operator consists of a minus sign enclosed in parentheses,
(-).
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7.
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The outer join operator is placed on the side of the comparison that is
deficient or is missing the matching rows.
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8.
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The number of joining conditions required to join tables is always one less than
the number of tables being joined.
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Modified True/False
Indicate
whether the statement is true or false. If false, change the identified word or phrase to make
the statement true.
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9.
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A(n) Cartesian Join replicates each row from the first table with every
row from the second table. _________________________
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10.
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A(n) non-equality join is when a table is joined to itself.
_________________________
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11.
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The NATURAL JOIN keywords are appropriate when joining two tables that
have more than one commonly named and defined field. _________________________
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12.
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Equality, non-equality, and self-joins are broadly categorized as outer
joins. _________________________
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13.
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If you are joining five tables in a SELECT statement, five joining
conditions will be required. _________________________
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Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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14.
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A column qualifier is separated from the column using which symbol?
a. | comma (,) | c. | period (.) | b. | plus sign (+) | d. | percent sign
(%) |
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15.
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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 | c. | JOIN...USING | b. | JOIN...ON | d. | none of the
above |
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16.
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A table alias cannot be assigned in the FROM clause if which of the following
keywords is used to join tables?
a. | NATURAL JOIN | c. | LEFT OUTER JOIN | b. | JOIN...ON | d. | FULL OUTER JOIN |
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17.
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Which of the following can only be used to link tables that have a common
column?
a. | FULL OUTER JOIN | c. | NATURAL JOIN | b. | JOIN...ON | d. | CROSS JOIN |
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18.
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Which of the following set operators will display only the unique results of the
combined SQL statements?
a. | UNION | c. | INTERSECT | b. | UNION ALL | d. | MINUS |
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Completion
Complete each
statement.
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19.
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A column ____________________ indicates the table containing the column being
referenced.
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20.
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Joins are classified as ____________________ joins if the results can only
contain the rows that had matching values in each table, rather than rows being matched with NULL
values.
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21.
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To display rows from one table that do not have a corresponding row in the other
table, you must create a(n) ____________________ join.
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22.
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A(n) ____________________ outer join is necessary when you need rows returned
from either table that do not have a matching record in the other table.
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23.
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The ____________________ set operator is used to display the combined results
returned by multiple SELECT statements.
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24.
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The ____________________ set operator is used to display the rows returned by
both SELECT statements.
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25.
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The ____________________ set operator is used to display the results that were
returned by the first query that were not also returned by the second query.
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