Test 2

Question 1

Relational Database

Answer 1

relationships in the database

Question 2

Database relationships

Answer 2

-connects two table in a data base with a common field
-can be shown as a schema diagram

Question 3

Why relationships?

Answer 3

-include data from multiple sources
-keep data organized
-reduce data redundancy
-ensure the consistency/accuracy of data

Question 4

Data redundancy

Answer 4

two fields repeat the same info

Ex: a number correlating to a specific name

Question 5

Foreign Key

Answer 5

a field that connects to the primary key of another table

Order Table: Menu ID
Menu Table: Menu ID

Question 6

Foreign Key Constraints

Answer 6

help prevent errors in the data

Question 7

Referential Integrity

Answer 7

-Every value of a foreign key field has to be a value of the primary key field
-Must have corresponding values between tables
-Ensures consistency/accuracy

Question 8

What are the two types of referential integrity relationships?

Answer 8

-one to many
-one to one

Question 9

One-to-many

Answer 9

Each primary key value can show up many times as foreign key

Question 10

One-to-one

Answer 10

primary key connected to primary key

Question 11

Subdata sheet

Answer 11

-shows the data in the related table
-all records in the related table connected to the record
-if you change data in this view it changes in the related tables

Question 12

Summary queries

Answer 12

-calculates statistics about groups of records

-returns the unique number of records

Question 13

Group by field

Answer 13

-query groups the query results by this field
-usually applied to categorical fields

Question 14

What happens if group by is applied to multiple fields?

Answer 14

-query will group the results by all of the fields
-If all groupings of field A are within field B you will see same results

Question 15

How to approach a problem

Answer 15

-Examine the data
-examine the tables
-import each table one at a time
-make adjustments according to question
-define relationships
-create a query for each question

Question 16

Calculated field

Answer 16

-field of data that can be created based on the values of other fields

Question 17

Expression

Answer 17

-combination of field names, operators, and functions that result in a single value

Question 18

Function

Answer 18

formula that returns a value

Question 19

ways to create a calculated field?

Answer 19

-builder function
-type formula in empty field

Question 20

Pro/con of builder function

Answer 20

-less likely to have format error
-can take a little longer

Question 21

Pro/con of typing formula into empty field

Answer 21

-can be faster
-more likely for format error

Question 22

Common functions

Answer 22

-date
-pmt
-left
-right
-len

Question 23

date function

Answer 23

-calculates number of days between today and the date in the birthdate field

Date()-[birthdate]

Question 24

pmt function

Answer 24

-calculates monthly payment

pmt([rate],[term],[loan])

Question 25

Left function

Answer 25

-returns the first two characters of the entry in the last name field

left([lastname]),2)

Question 26

Right function

Answer 26

-returns the last three characters of the entry in the last name field

Right([lastname],3)

Question 27

Len function

Answer 27

-returns the number of characters of the entry

Len([description])

Question 28

Subquery

Answer 28

-create a query using a query
-used when certain criteria keeps you from grouping items the way you want

Question 29

Query do NOT

Answer 29

-have same table more than once
-have two unrelated tables
-have a query and a table in the second step query

Question 30

What do all the query do nots have in common?

Answer 30

-all have the same problem
-query will keep running because tables or queries are not related
-get many duplicate results

Question 31

At Birmingham’s Best Coffee, your database does not allow your customer to order hamburgers. What is the most likely reason?

Answer 31

Referential integrity

Question 32

In your Access database, it shows an infinity sign on a relationship. What does the infinity sign represent?

Answer 32

the side with foreign key

Question 33

How is a foreign key different from a primary key?

Answer 33

A foreign key ensures referential integrity.

Question 34

To have 5 related tables in a relational database, how many primary-foreign key relationships are needed?

Answer 34

5-1=4

4 relationships