DeVry University Introduction to Database (CIS336) Study guide Exam

CIS336 Study guide Exam Introduction to Database DeVry University

Study guide for IT478 Exam #2 – on 3/23
There will be 2 parts – Part 1 (60 points) will have 60 T/F and MC questions. I
have included several examples below.
Part 2 (40 points) will be take-home. It will have 8 questions. I will hand-out part
two on the day of the exam. You will submit part 2 via TeggieNet
From chapter 4
1. In a join, column names need to be qualified only
a. in inner joins c. when the code is confusing
b. in outer joins d. when the same names are used in both
tables

2. If you assign an alias to one table in a join, you have to
a. assign them to all of the tables
b. use that name for the table
c. qualify every column name in the query
d. qualify all of the column names for that table
ANS:b
3. When you need to code multiple conditions in a join, it’s best to
a. code all conditions in the ON clause
b. code only join conditions in the ON clause
c. code all conditions in the WHERE clause
d. code only join conditions in the WHERE clause
ANS:
4. You don’t ever need to code a right outer join because
a. left outer joins are just as efficient c. right outer joins are less efficient
b. left outer joins are easier to code d. right outer joins can be converted to left
outer joins
ANS:

5. Which of the following is not a reason for using the explicit syntax instead of the implicit syntax for
joins? The explicit syntax
a. is easier to read and understand c. can be used for more than two tables
b. lets you separate the join and search
conditions
d. lets you combine inner and outer joins
ANS:
6. In a cross join, all of the rows in the first table are joined with all of the
a. distinct rows in the second table c. unmatched rows in the second table
b. matched rows in the second table d. rows in the second table
ANS:
7. When you code a union that combines two result sets, which of the following is not true?
a. Each result set must have the same number of columns.
b. The result sets may or may not have any duplicate rows.
c. The corresponding columns in the result sets must have compatible data types.
d. The result sets must be derived from different tables.
ANS:
8. When you code a union with the INTERSECT keyword to combine two result sets, the union
a. includes only rows that occur in both result sets
b. excludes rows from the first result set if they also occur in the second result set
c. includes all rows that occur in both result sets if the primary keys are the same
d. excludes rows from the second result set if they also occur in the first result set
ANS:
9. A full outer join includes rows that satisfy the join condition, plus
a. rows in the left table that don’t satisfy the join condition
b. rows in both tables that don’t satisfy the join condition
c. rows in the right table that don’t satisfy the join condition
d. the Cartesian product of the two tables
ANS:
Code example 4-2
SELECT vendor_name, invoice_number
FROM invoices LEFT JOIN vendors
ON invoices.vendor_id = vendors.vendor_id

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