Download Top of Form Week 3: Tables, MS Access vs. Excel, and Data Integrity

Week 3: Tables, MS Access vs. Excel, and
Data Integrity - Discussion
Conceptual Database Design (graded)
Why do you think organizing data into tables and relationships is a good way to design a database? How do
related tables improve the accuracy of data in a database?
Responses
Response
Benefits of
tables &
relationships
Author
Jennifer Reed
Date/Time
7/22/2012 2:21:04 PM
Tables and relationships help the user sort through and organize large amounts of data.
When the data is organized in a systemic fashion, the data will be easier to work with.
If a large amount of data was entered into Excel, the spreadsheet would have several
(in some instances, thousands) columns and rows. The spreadsheet probably wouldn't
make much sense and seem somewhat messy and overwhelming. It would also be
limiting and difficult to inquire about specific data by using a spreadsheet. By using a
database such as Access, this large amount of data can be broken down into entities
and attributes that can later be formed into relationships thus increasing efficiency.
When creating a database, each piece of data is stored in only one place because of the
ability to compare and combine data in a database. "This is related to the process of
normalizing the database, which eliminates the need for duplicate data" (Larson, T.,
n.d.). Also, updating data is easier in a database since the data is stored in only one
place, where as a spreadsheet may contain the same data in several different cells.
When tables and relationships are used to design a database, the data is organized in
structured way and adding/editing/deleting data is easier.
Referential integrity improves data accuracy in a database. When a relationship is
formed between two tables and referential integrity is enforced, data cannot be entered
into the foreign key table without first being present in the primary key table. Also,
data cannot be deleted in the primary table if the data exists in the related table.
Referential integrity prevents the creation of records that reference other records that
no longer exist, otherwise known as orphan records-a single record that is not related
to any other records.
Larson, T. (n.d.). What Are the Benefits of the Relational Database? retrieved from:
http://www.ehow.com/list_5985480_benefits-relational-database_.html
http://office.microsoft.com/en-us/access-help/create-edit-or-delete-a-relationshipHA010341606.aspx#_Toc269467499
RE: Benefits
of tables &
Navdip Singh
relationships
7/26/2012 9:36:03 PM
Check MS Access' help under search and put in "encrypted". It may tell you
how to convert the data into a readable format
RE: Benefits
of tables &
Charlotte Hagans
relationships
7/24/2012 8:19:40 AM
I think that referential integrity is actually a good thing. I look at it as a
double check for lack of a better word. You can't delete it from one when its
in another place. This is a really good thing when working with a database
that contains thousands of rows of information.
RE: Benefits
of tables & Yesenia Lopez
relationships
7/25/2012 9:57:41 PM
Organizing data into tables and relationships is a good way to design a
database because tables and relationships help provide access to updated
and accurate information. Once relationships are created the database can
easily accommodate change. To ensure accuracy in a database the
referential integrity rule can be placed. The related tables must be consistent
with one another. Changes that are made in one table will affect the other
related tables as well. Referential integrity also prohibits users from
deleting a record in one table if it has records in related tables. This ensures
the integrity of the data in the database and improves overall data accuracy.
Grauer, Robert T., Mast, Keith, Poatsy, Mary Anne, Frost, Raymond, Day,
John, Slyke, and Craig Van (). Database Design Essentials for Business for
DeVry University [2] (VitalSource Bookshelf), Retrieved from
http://online.vitalsource.com/books/9781256091646/id/p2accch01lev3sec18
RE: Benefits
of tables & Staci Lee
relationships
7/24/2012 2:21:46 PM
I would have to agree with you. When you are dealing with a lot of
information this helps and you want to makes sure your information
is accurate and easy to attain.
RE: Benefits
of tables & Charlotte Hagans
relationships
7/27/2012 3:35:41 PM
Another way to think about it is you don't want to spend
hours searching for information that you could find rather
quickly if the database is organized correctly. The boss
would not be pleased if he couldn't find what he was looking
for easily either.
RE: Benefits
of tables & Yesenia Lopez
relationships
7/29/2012 10:25:06
PM
I also agree that a well designed database can help time
management for the user, but also for the creator. When the
database is created properly the first time if there are any
changes they would be minimal and easier to handle. If
changes were needed in a poorly designed database it could
be very difficult and time consuming to determine where the
changes need to be placed and it could affect the entire
database. The user may even have to start the database from
scratch if the changes were too complicated. This is why
asking the necessary questions is important when designing a
database to make sure that there will not be any missing
information.
RE: Benefits
of tables & Sean Mccauley
relationships
7/24/2012 2:27:56 PM
Tables and relationships are good ways to design databases because
it give an order and logical organizational aspect to a large amount of
information involved in a database. Having a simplified way to
access the information and data involved has an immediate effect on
a database and the ease of usage. Tables that are related to each
other improve the accuracy of data in a database in a couple of
different ways. First and foremost, a database with related tables can
assist in accuracy by being conducive to a large amount of data. The
information in tables may contain similar/the same data. If these
tables are related and are able to be viewed easily with each other,
possible inaccuracies could be found much quicker than if the tables
were not organized by relation and simply thrown together. I agree
with Charolette that referential integrity is a "double check" or a
security blanket in order to maintain the data in a database.
RE: Benefits
of tables & Willeen Smith
relationships
7/25/2012 4:30:25
AM
Sean I have to agree with what you are saying about
tabes and relationships, they really are a good way to
keep the data organize and they do involve large
amount of information. I really can't imagine what
this world would be like if we didn't have tables and
relationship and other equipment to assess with all the
terminology that m have today. Storing large amount
of data is very important to all companies that do web
base business. You have made a great post.
RE: Benefits
of tables & Mark Ramsey
relationships
7/25/2012 8:59:32
PM
Certain principles guide the database design
process. The first principle is that duplicate
information (also called redundant data) is bad,
because it wastes space and increases the likelihood
of errors and inconsistencies. The second principle
is that the correctness and completeness of
information is important. If your database contains
incorrect information, any reports that pull
information from the database will also contain
incorrect information. As a result, any decisions you
make that are based on those reports will then be
misinformed.
A good database design is, therefore, one that:




Divides your information into subject-based
tables to reduce redundant data.
Provides Access with the information it
requires to join the information in the tables
together as needed.
Helps support and ensure the accuracy and
integrity of your information.
Accommodates your data processing and
reporting needs.
http://office.microsoft.com/en-us/accesshelp/database-design-basics-HA001224247.aspx
Conceptual
Design
Professor Schiller
7/22/2012 3:33:02 PM
Class:
When designing and developing a database, it is imperative that we utilize a conceptual design process.
But, what is a conceptual design process? Do some reading and research on this topic, then list and
discuss the major steps of the conceptual design process in your answers.
Let's go beyond the "what", and also start discussing the "how", and even more interesting, the "why".
Once we have this background, we can go on to the questions at the top of the thread.
RE:
Conceptual Rebeka Andrade
Design
7/24/2012 3:54:42 PM
When engaging in conceptual design, you do not need to worry about the rules of relational
databases. Conceptual design is implementation free, meaning that the exact means of
implementation is not a concern. All that you are worried about during conceptual design are
the entities about which the database must store data, what data must be stored, and how the
entities are related to each other. Conceptual design discusses the important topic of
normalization, which is the process of ensuring that a database design meets the relational
rules. Violating these rules can result in data inconsistencies.
Database Design Essentials for Business, Second Edition, Page 10 (Printed Page F-10)
RE:
Conceptual Kelly Dutcher
Design
7/24/2012 5:27:18 PM
I found this website : http://www.ehow.com/about_4570087_conceptualdesign.html
As the article states, "the bottom line is that good conceptual design will be
comprised of the creation of an idea, the exploration of the intentions of an
idea and the representation of an idea."
So what I've gathered from doing some reading is that conceptual design is
when you come up with a "concept" or idea and start to work on how to make
that idea a reality. Depending upon the scope of the information the
conceptual design process could include drawing up blueprints, drawing
diagrams, making lists, researching etc.
RE:
Conceptual Yuri Lazare
Design
7/23/2012 6:08:48 PM
Conceptual Design involves gathering information from the end users of the
database and putting together a roadmap of tables with all the information
needed to meet the business needs. Databases are designed to meet the
information needs of an individual or business but without proper planning
the end user may not be able to extract the information they need. Conceptual
design allows the creator of the database to understand the needs of the
customer or end user, understand the problems the database is meant to solve,
know the existing limitations and even help streamline the operation and
processes of the business.
RE:
Conceptual Kinja Cager
Design
7/23/2012 11:39:21 PM
Conceptual design process, i believe there is 5 steps to this process.
1.Fact Gathering-putting your best ideas together in order to begin.
2.Processing-note taking, sketching and organizing the work and information
you just gathered.
3.Design-If the first two steps go well then the designer will be able to just
flow through this step of putting all their thoughts together to create a
finished product
4.Refinement-Once the design is completed , this step is where you would
apply any finishing touches in order to bring it up to industry standards
5.Implementation- Getting your finished product out to vendors
RE:
Conceptual Sean Mccauley
Design
7/26/2012 10:36:19 AM
Kinja this a good explanation of the processes involved in conceptual
design. It illustrates that there is not an immediate focus on the
details and structure right away. Rather, there is a focus on the
concept of the data involved that can allow for a more organized end
product. There must always be a beginning step of information
gathering and understanding. This can be compared to just about any
aspect of informative tasks. Information gathering can set the ground
work for the steps to come. With a good understanding of the data
you'll be working with, it will be much easier to begin moving
forward with the next steps such as designing the database itself and
checking to ensure the information is accurate and not redundant.
The ER model begins to be used once the information is understood,
and thus begins the actual organizational aspect of the database
itself. The importance of using a conceptual design process, jus to
reiterate, is that it allows someone to become familiar with the data
they will be working with, begin organizing said data in logical ways
and eventually allowing that data to be presented in a way that allows
understanding to those that will be utilizing it.
RE:
Lemmesha Wilbert-James
Conceptual
Design
7/28/2012 4:18:39 PM
This is very good and very useful to those who don'tknow what
conceptual design is. You break it down so they understand not to
rush into it and give them step by step that they need to follow to get
the design done. Great Job!
RE:
Conceptual Jennifer Reed
Design
7/24/2012 6:10:10 AM
Conceptual design involves requirements gathering and constructing
a diagram (ERD) of how the database will be created in the DBMS. The first
step for a developer when creating a conceptual model is collecting data. It
would be difficult for a developer to create a successful database without
being well informed about the business or organization. Data is collected
regarding the policies and operation of the organization/business; data is also
collected through interviews, research, and questionnaires. The information
gathered will help identify primary keys, relationships, data sizes and their
growth rates as well as the process that should be modeled in the ERD. The
ERD created in the conceptual model will describe the data that will be
entered into the DBMS and how the data is related by using entities,
attributes, and relationships.
Reasons for Conceptual Modeling:
-Independent of DBMS-a model (ERD) can be created that is not directly
related to any specific database. Meaning, a model is created prior to entering
the data in a database-the model is separate from the database.
-Allows for easy communication between end users and developers.
-Has a clear method to convert from high-level model to relational model.
-Conceptual schema is a permanent description of the database requirements.
Reference: http://www.dcs.vein.hu/CIR/cikkek/conceptual_design.pdf
RE:
Conceptual Joelle Yule
Design
7/22/2012 6:10:11 PM
According to our text, there are 5 main steps in the Conceptual Design
Process (
1. Identify Entities and Create Tables - Brainstorm
- Ask yourself how many, or is there more than one?
- Is there change/variation over time? - If yes, there may be a requirement
for another table
- Ensure each entity is a separate table
- Make all tables: if am entity is a possibility, make the table as it can be
removed later if it's not required.
2. Relationships
- Demonstrate/create the relationships between entities
- Most relationships will be one-to-many
- Create the required associative tables for the many-to-many relationships
3. Fields
- Determine the attributes of the entities
- Set them up as fields within the tables
- Double check that a single field that exists within a table by itself really
needs to be there, or if it can be combined into another table/entity
4. Primary Keys
- Determine the Primary Keys
- Ensure all child tables have their respective foreign keys (Note: Parent
Primary Key always has to come first!)
5. Data Types
- Set data type and field size
- All keys (primary and foreign) must be matching in data type and size
All of this can be found in further detail beginning on page F-30 in our text.
Grauer, R. T., Mast, K., Poatsy, M.A., Frost, R., Day, J., and Slyke, C.V..
(2010) Database Design Essentials for Business for DeVry University, 2nd
Edition. Boston, MA: Pearson Learning
Solutions.
RE:
Conceptual Ashlie Ouellette
Design
7/22/2012 7:26:07 PM
A conceptual design is a 5 step process which includes:
Step one: Represent entites as tables
step two: determine relationships
Step three: list fields
step four: identify keys
step five:determining data types
these are listed in the text book on F-30
first you have to have entites liek the persons places and things, you have to
determine the releationship, list the fields identify keys all keys much have
primary keys to uniquely identify, and determine data types the size etc.
RE:
Conceptual Willeen Smith
Design
7/22/2012 7:55:15 PM
I found this article that give a great view of what conceptual design
is. Conceptual design, along with need identification ad analysis,
make up the initial stage of the design process. Need analysis
transforms the often vague statement of design task into set of
design requirements. Conceptual design encompasses the generation
of concepts and integration into system-level solutions, leading to a
relatively detailed design. They focus on parameter analysis, a
methodology that leads the user through the design process, helping
identify critical issues (parameters) of the design and propose
configuration-specific examples and variety of real-world
case studies. This site is very interesting and they even have a
design on the website.
Reference:
http://eyedave4.wordpress.com/other-portfolio-projects-by-david-mfreeman/2b-what-is-conceptual-designing/
RE:
Conceptual Arlene Lazare
Design
From what I
the process
view of the
independant
7/23/2012 7:25:35 AM
have read, conceptual design is
of creating a data model for each
real world issue which is
of physical consideration.
This step involves:
- Constructing the ER model
- Check the model of redundancy
- Validating the model against user
transaction to ensure all the scenarios are
supported
http://www.prowareness.com
RE:
Conceptual Sharon Gibson
Design
7/24/2012 12:57:29 PM
Conceptual design consists of requirements analysis and database analysis as one.
Conceptual design focuses on understanding the business and its functional areas
or business processes. The first step in the conceptual design is to determine
specific needs of the database; which focuses on the following:
1. What are the information needs? What kinds of outputs are needed, what
2.
3.
is currently generated, and how adequate is it?
Who will use the information generated by the database, how many types
of users are there, and what are their data view requirements?
What are the data elements needed to produce information? What are your
data entities, attributes, and relationships among data?
RE:
Conceptual Navdip Singh
Design
7/28/2012 11:14:23
PM
A collection of interrelated data together with a set of
programs to access the data, also called database system, or
simply database. The primary goal of such a system is to
provide an environment that is both convenient and efficient
to use in retrieving and storing information.
RE:
Conceptual Jb Avery
Design
7/25/2012 7:05:23 PM
A conceptual design database involves modeling the collective information at
a high level of abstraction without using a particular data model.
RE:
Conceptual Caromill Almanzar
Design
7/25/2012 10:08:10 PM
There are two theoretical definitions, as follows:
1) Conceptual design process, is the process of constructing a model of the
information used in an enterprise, independent of all
physical considerations. [Conn1998]
or
2) Conceptual database design, is the process of building a model of the
essential part of the enterprise business process and the used information,
independent of all physical considerations.
The focus of the conceptual database design has to answer the question of the
reason for persistent data. Last but not least the conceptual database design
handles the data view of the business process. It is a part of the
business model of the entire enterprise. It defines the global need for
persistent data, but not the physical details of the implementation. It includes
use cases and use case realization, including activity, collaboration,
and sequence diagrams, but does not require all of the content.
Reference:
1) Textbook
2) http://www.uml.org.cn/oobject/pdf/logical.pdf
3)http://www.dcs.vein.hu/CIR/cikkek/conceptual_design.pdf
RE:
Conceptual Rod Chapman
Design
7/28/2012 6:35:50 PM
Conceptual design would be similar to brainstorming in that you decide what you want the
outcome to be, without worrying about the rules and concerns on how to get there.
RE:
Conceptual Adam Rogers
Design
7/28/2012 8:46:13 PM
Modified:7/28/2012 8:51 PM
The conceptual part of the design process is where the outline for the database
is thought up. This is where you brainstorm about all the data you may need.
The tables and relationships are not the top concern during this phase because
we want to make sure nothing will be left out. It helps to put it down on paper
because seeing one piece of data that you know you will need to include can
remind you of another. Then after you have all the data, then you can start
grouping it together into groups that will make sense.
RE:
Conceptual Deanna Clavell
Design
7/26/2012 6:32:45 PM
When using a conceptual design process we must take into consideration the
following. We must gather all information related to the topic. You must
determine the specific needs of the database or program. What exactly are we
using it for, when are we using it, and what will it tell us. We then have to
determine the cost of it. Will is cost more upfront or later on? What included
features will it have. Will it go above and beyond our primary needs? What
type of portability will it have? Wireless, will it need a network? What
underlying technology will it entail, do you need to hire additional bodies to
maintain the databases? Will it be compatible with other software being used?
What hardware requirements or computer system will it be compatible with?
RE:
Conceptual Professor Schiller
Design
7/28/2012 1:51:28 PM
Class: Awesome job on the steps required for conceptual design.
Once a conceptual design is completed, you can implement it with
Access or the other relational databases that we have mentioned
earlier.
RE:
Conceptual Shannon Busse
Design
7/29/2012 6:45:21 PM
Conceptual design means that the exact means of implementation is not a
concern. The only thing that is worried about during the conceptual design
process is the entities about which the database must store data, what data
should be stored, and how they are related to each other. A good thing to
watch for is normalization. This is the process of ensuring that a database
design meets the relational rules. Inconsistencies can become if these rules
are not followed.
Database
design
Staci Lee
7/23/2012 1:45:02 PM
It is important to organize the tables and relationships because this is what is going to
maintian all your data and organiztion and caorrect relationships is important for
accurate information.
Organization
Nicole Palazzolo
7/23/2012 4:31:06 PM
I think one of the main reasons organizing data into tables and relationships is a good
way to design a database because it keeps everything in order and it will be easier to
create your database afterwards. It will also be easier for someone to locate any
information that might need changed in the future. Relationships are especially helpful
because it will tell you where you can find certain information in more than one
location when you need to alter the information.
RE:
Organization Sara Floodberg
7/24/2012 8:57:25 AM
I agree! If you start with the design you may be missing important
information and mess up the relationships. Slowly adding to the ERD
construction (the 5 step process) insures that you are seeing the big picture
and the details. The design of the database and reports will be a lot easier.
I have started to look at all this like my filing cabinet. I have have one that
has a few drawers, one is my old records that get moved to that drawer when
the account is closed or no longer in use ( I keep records up to a certain
amount of time incase I need to refer back to them, but I want them out of my
current drawer to save space and time to look up something. With in my
current drawer I have it separated into different things like taxes, bills,
insurance, legal, school and so on. Within each section I have them separated
into their individual files. I have some files like my cars that have a few
different files because I keep records on the fiance company, insurance
company and maintenance and misc records. It sounds confusing, but I have
started to think about making my files into a database and it has started to
help me understand designing a database!
RE:
Organization Nicole Palazzolo
7/24/2012 9:11:05 AM
Organizing can also prevent you from forgetting a lot of information.
This will ensure that you have everything you need so nothing is
omitted.
RE:
Organization Kenneth Joa
7/24/2012 12:38:29 PM
Agreed, when you do this it condenses the data so its not just everywhere and
disorganized. In addition to the ascetic benefits of not having a ton of data
just floating around in utter chaos. This like Nicole says makes it easier to
change in the future and find certain data if you have any desire to look for
specific information because it already organized.
RE:
Organization Ashlie Ouellette
7/25/2012 8:04:16 AM
yes im going to agree with you nicole, when you can keep everything in order
and everything that you need together it makes for a better database. You
dont have to worry about if you missed soemthing. Relationships i think
saves you time looking for them later like you said location if you have
everything done and out in chart you can find things or even notice things you
wouldn't if you didn't have them together.
RE:
Organization Caromill Almanzar
7/27/2012 11:10:08 PM
I agree with you Nicole, the tables help to compile all the most important
information that wants to be gather so it will be easier to search and modify in
any period of time. Also the relationship creates a bond between data that
allocates the information, so when retrieving data there were not be any
excessive, but the data that was asked to be retrieved.
RE:Benefits
of tables and
relationship
Jb Avery
7/24/2012 9:29:00 PM
Relationship connects the tables together to show relationship. They can show
accuracy of data because they can have more than one relationship.
Data
and
Tables
Deanna Clavell
7/24/2012 10:06:44 PM
Organizing Data into tables and relationships allows you to organize your information.
This allows you to see what relates to what and how it affects other areas. This will
allow you to fully examine your criteria and get the most complete and accurate
reporting.
RE: Design
ProcessProfessor Schiller
More
questions
7/25/2012 2:03:26 PM
Modified:7/25/2012 2:06 PM
Class: Awesome work so far on the steps in the design process. Here are a couple of
questions to keep it rolling.
1. What questions can help identify an entity?
2. What questions can determine whether a relationship is one-to-one, one-tomany, or many-to-many?
3. Provide examples of many-to-many relationships from your work life and
explain how to create an associative table to handle the many-to-many
situation.
RE:
Design
Process- Brittani Wigal
More
questions
7/25/2012 8:05:33 PM
What things do we
need to store data about? What things
are essential to the organization? What
things do we talk about in the organization? What questions and reports do we
need to process? What are the important
people, places, physical things, organizations, events and abstract concepts in
the organization?
http://www.it.iitb.ac.in/~palwencha/ppt/Intro%20to%20Databases/EntityRelationship%20modelling%20(IEEE).pdf
I agree with the article I read on the questions of how to identify an entity.
RE:
Design
Process- Kelly Dutcher
More
questions
7/25/2012 8:32:07 PM
So I'm thinking in order to help identify an entity one would have to ask what
information you will need in order to fulfil the purpose of the database. One
needs to fully understand that intent of the database in order to determine
what the proper entities will be.
As far as determining what type of relationship exists you need to ask
whether or not one entity is capable of [insert verb] the other entity. From
here you need to identify how many of each entity is able to [insert verb] how
many of the other entity. Depending upon the answers which you come up
with you will determine what type of relationship is present between the
entities.
An example of a many to many at the bar/restaurant that I work at is when we
are ordering liquor. We deal with many different liquor distributors and
many of these distributors sell the same type of products but just different
brands. So there are many different distributors that sell vodka for instance
and there are many different vodkas sold by each distributor.
RE:
Design
Process- Willeen Smith
More
questions
Hello Kelly
7/26/2012 2:25:55 PM
You have made a great example of many to many it's so true
regarding the different liquors. Some are almost the same
just different names and different prices and made my
different companies. That would make a very interesting
table if we had to see who made what liquor and what brand,
boy that's a list that could go on for some time. But you
made a really good example of many to many.
RE:
Design
Process- Rebeka Andrade
More
questions
7/25/2012 10:53:55 PM
Different questions that can help identify the relationship would be perhaps
the ratio of employees to a manager or the ration of customers to employees.
Also the amount of visits to that location like the dentist or a grocery store. It
would also have to vary through the different relationships you can make
depending on the combinations of many-to-many or one-to-many.
RE:
Design
Process- Jennifer Reed
More
questions
7/26/2012 5:56:22 AM
Modified:7/26/2012 5:56 AM
As we all know, an entity is a person, place, thing, event, or object in which
data will kept about. An entity will normally have attributes that will describe
it further. Along with gathering information, identifying entities in one of the
first steps in the modeling process. After the information is gathered to begin
creating the database, entities can be identified by working through the
information and highlighting words (persons, places, things) that correspond
to potential entities. The designer of the database should ask Who? What?
Why? about the information to also aid in identifying entities. A true entity
should appear more than once in the information being reviewed. Some
things may appear as entities but should not used as entities such as
processes, calculations, reports, and facts about entities.
Relationship describe how the entities interact. Questions that could be asked
to determine relationships would be:
Does data in table A relate to table B in one or more ways?
Are there many items in table A that relate to many items in table B?
Borysowich, C. (2007). Understanding Entities in E-R Diagrams. retrieved
from: http://it.toolbox.com/blogs/enterprise-solutions/understanding-entitiesin-er-diagrams-14255
http://www.javaguicodexample.com/erddatabasemodelnotes.pdf
RE:
Sara Floodberg
#3
7/26/2012 7:51:59 AM
Modified:7/26/2012 7:59 AM
Okay, I choose this one because I am having troubles with it in the iLab!
So I don't know if this works but lets say for christmas there are many kids
and many toys. One kid can have many toys and one toy can go to many kids,
so the associative table could by named Santa?
Kid Table
PK Kid ID
Girl or Boy
Age
Toy Table
PK Toy ID
Girl or Boy
Age Group
Santa Table
Present ID
FK Toy ID
FK Toy ID
Good or Bad
Coal or Toy
RE:
#3 Lorrie Sullivan
7/28/2012 8:49:57 PM
I found this bit of information which helped me understand the
Professor's response better.
The database designer is responsible for translating that relationship into
something that will be functional. To do this the designer has to create a
third table… the associative table. The essential purpose of an associative
table is to store foreign keys only. In other words, it doesn’t do anything
except store the association relationship between a user and a group.
Here is the link to the entire article:
http://www.phpbbdoctor.com/blog/2007/02/04/database-design-1-
using-associative-tables/
RE:
#3 Professor Schiller
7/28/2012 1:58:22 PM
Sara, Your third table (associative table) would be:
Santa Table
Fk/Pk Kid ID
Fk/Pk Toy ID
RE:
Design
Process- Ashlie Ouellette
More
questions
7/25/2012 2:35:47 PM
A many to many that i can think about here at work would be we just loaded
a computer in our shop so when an order is ready to be ran it needs to be
scanned which will tell you where the paper is located that you need to fill the
order and then it will need to be scanned after to make that paper come out of
inventroy, thy want to know who done the job, and which press.
I would have employee as a table, I would have Each press as a table so i
would have three here, and then i would have inventory.
under employee i would have ID, Name, Which department.
under each press i would have Name of person running press, I would have
job number, Paper.
and then under inventory i would have name of person that ran job, job
number, paper style, and qty.
RE:
Design
Process- Yuri Lazare
More
questions
7/25/2012 6:27:24 PM
While working as a banker we offered many different products so in order to
effectively market these products to our clients we had split them up by type.
For example we had multiple credit card products but each is designed for a
customer with a particular lifestyle. We had many customers and we would
sell the many products therefore most clients had multiple products so we
basically had to group them by customer portfolio. A customer's portfolio
would include many products but at the same time a customer could have
multiple portfolios if he had products associated with his business, or joint
products with his wife. Therefore the products table would serve as the
associative table between customers and portfolios as customers would have
a many to many relationship with portfolio.
RE:
Design
Process- Arlene Lazare
More
questions
7/25/2012 4:36:29 PM
I had to do a little online research for this
question but here's what I gathered.
Generally, there are just two queries that
essentially needs be asked, in order to start
the degree of the relationship that occurs
between any two entities.
In order to identify the degree of the relationship between
the entities X and Y the following two questions need to be
asked.
Question 1
Can an occurrence of X to be associated with more than one
occurrence of Y?
Question 2
Can an occurrence of Y to be associated with more than one
occurrence of X?
Each of these questions can be answered 'Yes' or 'No' and
both questions must be answered. This means that there are
four possible outcomes as shown in the table.
The nature of the relationship associated with each outcome
is as follows:
Option 1, Question1 equals Yes, Question2 equals No.
In this case a one-to-many relationship has been identified,
represented by the relationship line shown.
Option 2, Question1 equals No, Question2 equals Yes
As in the first case a one-to-many relationship has been
identified, represented by the relationship line shown.
Option 3, Question1 equals Yes, Question2 equals Yes
In this case a many-to-many relationship has been identified.
Many-to-many relationships may be shown in the early
'preliminary' data model in order to aid the clarity of these
early diagrams. However, such relationships are invalid and
are therefore always re-modeled using 'link entities' in later
diagrams. This process is explained later in the course.
Option 4, Question1 equals No, Question2 equals No
In this case a one-to-one link has been identified.
Legitimate one-to-one relationships are rare and it is likely
that this relationship is one that needs to be rationalized. The
methods used to investigate one-to-one relationships and to
re-model them where necessary are explained later in the
course.
http://www.itteam-direct.com/gwentrel.htm
RE:
Design
Process- Caromill Almanzar
More
questions
7/27/2012 11:30:50 PM
Modified:7/27/2012 11:31 PM
Answering question one:
The first step is to find out of type of organization I will be writing for. Let
say that I choose a manufacturer company, I can start with general questions
as:
A) What are the inputs and resources?
B) What are their Products and by-products?
c) What are their internal artifacts such as inventory and work in process?
Then I will have to gather more data and continue with other questions to
relate to the previous questions, such as:
a)How big is it?
b)How much is there?
c)How fast is the production?
d)How long does it take?
e)How much does it cost?
These questions to the ability of the information gathered would allow to
have a idea of the design of tables and the creation of the relationship in
between them.
http://www.databasedesign.co.uk/bookdatabasesafirstcourse/chap3/chap3.htm
RE:
Design
Process- Nicole Palazzolo
More
questions
7/26/2012 12:49:02 PM
#3:
The company I work for services vacuum cleaners. The most popular vacuum
cleaner we see come in is the Kirby. Many-to-many would be many
customers bring in many Kirbys. We see probably 4 Kirby vacuum cleaners a
week.
RE:
Design
Process- Jb Avery
More
questions
7/26/2012 7:08:21 PM
1).Questions to ask that would help identify and entity would be are there
more than one and is there variation over time.
2). one to many relationship is determine means that a row in one table is
matched to multiple rows in the second table, and a row in the second table is
matched back to one row in first table.
In many to many relationship, rows in one table are associated with many
rows in the second table, and a row in the second table is associated with
many rows in the first table.
RE:
Design
Process- Shannon Busse
More
questions
7/28/2012 7:01:25 PM
A many to many relationship that I deal with is "many customers are served
food by many employees." Many types of sandwiches are preferred by many
customers. Anything that is many to many relationship is when more than one
entity is followed by another more than on entity. We have one salad type but
is bought by many customers. One special ordered sandwich is ordered by
one special person. These could be examples of relationships that I deal at
with my job. I work in the food industry and we are one restaurant dealing
with many customers to keep them happy.
RE:
Design
Process- Sharon Gibson
More
questions
7/28/2012 2:29:45 PM
A many-to-many relationship is really two one-to-many relationships with a junction/link
table.
Because I am a singer I found this really cool example that made it easier for me to
comprehend the many to many concepts. The relationships for the Artists and Albums
database
ONE ARTIST can have ONE or MANY ALBUMS and an ALBUM can have ONE or
MANY ARTISTS related to it. This can be especially applicable if the ALBUM is a
COMPILATION of many artists. The ARTIST table consists of only the Artist ID and the
Artist Name (Full name).The ALBUM table consists of the Album ID, Album (or Single)
name the Genre ID (lookup to the Genre table), the Label ID (lookup to the Label table) and
the Album Release Date .The two tables are linked together by the LINK Artist_ Album
table. This table contains a composite Primary Key containing the Artist ID and the Album
ID. The database contains 2 main forms, where you can view Albums relating to each Artist
and Artists relating to each Album
http://www.databasedev.co.uk/many_to_many_example.html
RE:
Design
Process- Joelle Yule
More
questions
7/27/2012 10:07:00 PM
I am going to give it a shot at the associative table for a many to many
relationships because this is where I struggle the most. I have 5 sales reps that
each have 1200 customers. Those 1200 customers all place orders, but they
may not always place it with their regular sales rep. Sometimes, a different
rep takes the call and helps the customer. I want table with the employee
numbers, and a table with the customers. The associative table would be the
invoices, where the foreign keys would be the employee ID and the customer
number. I need to ensure I can see the invoice numbers of the orders that are
being placed by which customer, and which rep entered it. I could go further
into what was ordered, but that would require more tables - parts and then
tied to each invoice, as well as setting up customer addresses, contact names,
etc.
I hope I didn't confuse this further! lol
RE:
Design
Process- Mark Ramsey
More
questions
7/28/2012 4:51:23 PM
A one-to-one relation
If you think of relations as people sitting on a restaurant, this means that no one is sharing
a seat.
One-to-many and many-to-one relationships
An employee can work in only one department; this relationship is single-valued for
employees. On the other hand, one department can have many employees; this relationship
is multi-valued for departments. The relationship between employees (single-valued) and
departments (multi-valued) is a one-to-many relationship.
Many-to-many relationships
A relationship that is multi-valued in both directions is a many-to-many relationship. An
employee can work on more than one project, and a project can have more than one
employee. A many-to-many relationship can be expressed.
http://publib.boulder.ibm.com/infocenter/db2luw/v8/index.jsp?topic=/com.ibm.db2.udb.do
c/admin/c0004733.htm
RE:
Design
Process- Yesenia Lopez
More
questions
7/28/2012 9:33:18 PM
To determine whether a relationship is a one to many relationship is “will the parent table
have many relationships with child(ren) tables?” or “Will the personal trainer have more than
one client?”.
A question to determine a one-to-one relationship is “Will the parent table only have a
relationship with one child table and vice versa?” or “Does the cell phone have only one
phone number and is the phone number only assigned to one cell phone?”.
To determine if a relationship is many-to-many a question to ask is “if there will be more
than one relationships between several entities? “Will the high school students have more
than one teacher and will the teachers have more than one student?”
RE:
Design
Process- Deanna Clavell
More
questions
7/29/2012 9:11:35 PM
Questions to ask for a one to many would be Can the first item have or
provide many of the second items considered? But the second item cannot
have or provide many of the first.
For a many to many you must ask yourself can the first item have many of the
second and the second have many of the first?
Conceptual
Database
Lemmesha Wilbert-James
7/25/2012 2:36:49 PM
It is a good way to organize data into tables and relationships because it looks more
nice and more presentable to those who are looking at you design. If it wasn't like that
your information will be jumbled all over the place and and it wouldn't look decent
enough to want to figure out ok whats the relationship for this info and why is it
relevant to it. It improves it by making it that easier to read versus in excel where you
will have all your informaiton into colmuns and rows and you have to figure out what
goes with what and what is relevant and irrelevant.
RE:
Conceptual Kelly Dutcher
Database
7/27/2012 3:59:30 PM
LammeshaI agree that it makes the database much more presentable when the data is
organized into tables and relationships. It also eliminates the guess work
involved in trying to figure out how entities are related to eachother. But just
as much as it helps the user I believe it also is beneficial to the creator in the
same ways. By organizing the data into tables and defining their
relationships it helps the user to understand better how the information works
together and which features are most important to which tables.
Efficiency and
organization Adam Rogers
7/25/2012 4:37:12 PM
The reason for relational table is to organize data so that you can get information
quickly. Excel is a good program is you have small amounts of data to work with. a
couple hundred rows formed into a table will return results from the manipulation of
filters fairly quickly. However, when the data becomes large, several thousand rows,
the process slows down. With Access, or similar database program, the data is
organized into groups, or entities. When you send a query in a database it searches
only the relevant data. For example, if your local school system has 30 schools and
the superintendent has a database with all the information for every school, she can
make a query about grade average for only school A, and the database will only look
through school A's data, giving you a return much faster than Excel which would have
to go through all the rows to make sure it got all of school A's records.
The relationship mode improves accuracy by the grouping that is inherent to the
model. you keep all the information about school A in the school A table, it won't be
duplicated anywhere else. Avoiding data duplication is another way to speed up
a query. The lack of duplicated data also makes updating records easier because you
don't have to find more than one place in a database if you want to update someone's
address for example.
RE:
Organizing
Data
Lorrie Sullivan
7/25/2012 4:46:25 PM
Storing data in a proper form makes for a higher level of efficiency and performance.
Using the integrity rules ensure proper placement of data. [This reminds me of my
mother-in-law when I first started dating my now husband... she had her own
"database" in the refrigerator, the food pantry, and the linen closet. Each item had
a specific integrity, everything labeled appropriately - to her liking... who's food
was who's, who's towels, bed sheets, etc... You'd think I would have ran away and
never looked back! :o) ]
Access organizes your information into tables: lists of rows and columns reminiscent
of an accountant’s pad or a Excel worksheet. In a simple database, you might have
only one table. For most databases you will need more than one. For example, you
might have a table that stores information about products, another table that stores
information about orders, and another table with information about customers.
http://office.microsoft.com/en-us/access-help/database-design-basicsHA001224247.aspx#_Toc270678227
RE:
Organizing Yuri Lazare
7/27/2012 5:25:21 PM
Data
Lorrie the reference to your mother in law is very funny partly because I have
seen the same behavior in my in-laws. Organizing data did not hit home until
I completed this week's Lab assignment. Without the step by step instructions
I really had to study the data and figure how to arrange the relationships
according to the given rules. I guess I will know soon enough if I got the
concept of relationships correct.
RE:
Organizing Kinja Cager
Data
7/26/2012 11:03:15 PM
Lorrie, I can fully understand the mother in law story , except it is my mother
she has her house set up in a very similar fashion. In fact once you used that
example database structure makes a lot more sense and how important it is to
running a business efficiently.
RE:
Organizing Lorrie Sullivan
Data
7/28/2012 8:41:57 PM
Thanks Ladies. I did put some labels in the fridge one time and I thought my
husband was going to have a heart attach. LOL.
RE:
Organizing Staci Lee
Data
7/26/2012 9:46:59 AM
Lorrie,
That is a great example of databases and how they store data and orgainze
information.
week 3 Navdip Singh
7/26/2012 1:21:56 PM
Databases have become more and more indispensable in our daily life. We deal with
data everyday and everywhere - cellular phone contacts, medical records, logistical
data and transaction records, etc. They are all stored in databases. It is hard to imagine
what the world would be like without databases
RE:
week Rebeka Andrade
3
7/28/2012 9:21:18 PM
I would definitely have to agree, not just that, but the technology today is
definitely evolving and growing very fast. To rely on databases does have its
own pros and cons, but it definitely makes it easier to keep things on track
and not having so much paper work. Having electronic versions of all
documents and storing them in a well organized system keeps things much
easier to find and much more effective and efficient to use.
RE:
week Lemmesha Wilbert-James
3
7/26/2012 4:21:12 PM
That is true especially when storing any type of contract. Making sure that
information is put in properly so they don't mistake someone elses medical
records for someone elses or contrat for anyone elses for that matter too.
RE:
week Kenneth Joa
3
7/26/2012 5:06:12 PM
I agree as well with this statement. At my current job we use databases for
transaction records and inventory and it would not be possible or just very
difficult and inconvenient without the use of databases. They make doing the
work a great deal easier that it would otherwise be if we did not have access
to them. The world would be a lot less organized if we did not have anything
resembling a database that is for sure.
RE:
week Sara Floodberg
3
7/28/2012 1:07:40 PM
I agree! We have become very dependent on things like this. Could
you imagine going through a filing cabinet to find some or something
at a business! Or even doing the reports by hand!
RE:
week Kenneth Joa
3
7/29/2012 6:23:24 AM
I am too young to appreciate that statement, but I do
remember when I was younger I did go to work with my
mom and have to go through a filing cabinet to find
documents, it was not quite as quick as it is now. The "good
old days" of reporting and filing are so far behind us it is
easy to forget that this technology was made to replace that
way of doing work entirely.
RE:
week Rod Chapman
3
7/29/2012 6:17:27 PM
Sara, I agree with you, only a few years ago this kind of work would still
be done manually. Then along came spreadsheets which could help to a
certain point.
How do
related
tables
improve the Arlene Lazare
accuracy of
data in a
database?
7/27/2012 7:46:37 AM
Related tables makes it easier to retrieve data and
the amount of storage that is required is smaller.
That process is called normalization. Relational
database design is the process of organizing data
to minimize repetition. Normalization usually
involves dividing the database into two or more
tables.
Summary Conceptual
Design
Process
Professor Schiller
7/28/2012 2:09:35 PM
Thank you, everyone, for your participation in this week’s discussion! Please remember you still have 2
days left to make posts!
This week we covered Terminal Course Objectives: 2, 3, and 4. We discussed the Conceptual Design
Process. Here is a brief overview of what we discussed in this topic:
Conceptual Design Process Steps
Step 1: Represent Entities as Tables
• Entities are objects where we collect and store information. The information regarding entities is
stored as a table.
Step 2: Determine Relationships
• Relationships connect the tables together. Each table must connect to at least one other table in the
database.
Step 3: List Fields
• Entities usually have attributes. We model the attributes as fields listed inside each table.
Step 4: Identify Keys
• All tables must have a primary key to uniquely identify each record and the primary key must be
unique.
• All child tables must have a foreign key field to connect each child record with its corresponding
parent.
Step 5: Determining Data Types
• Determine the data type and size of each attribute as a final design step.
• Every attribute must have a data type describing the kind of information that may be stored in that
attribute.
Relationships and Keys
When designing a database, relationships are determined before defining the keys of the database. Once
the relationships are in place between tables we can then implement and define our keys, primary and
foreign. Be sure that the data type matches between the primary key and the related foreign keys.
RE:
Summary Conceptual Caromill Almanzar
Design
Process
7/29/2012 9:15:09 PM
It was pretty much difficult to define the many to many relationship. So I had
to do research. The situation is that there are many entities that are related to
many others, which it makes it harder. So I just discovered that in a many-tomany relationship, the only way to resolve this situation is minimizing
redundancy and create an intermediary table that would contain primary keys
from the main tables.
RE:
Summary Conceptual Sean Mccauley
Design
Process
7/29/2012 10:11:21 AM
This week was definitely a learning experience for me as far as understanding
database designs on a conceptual basis. The biggest question I have coming
out of this week and moving forward with the class is going to be associative
tables and how to gauge exactly what FK/PK applies and how to actually
relate the tables themselves. Going through the lab, figuring out how to break
down the data and list the fields appropriately was the simple steps. It's
difficult however to determine exactly when to associate a table with an
existing key or when instead to make a completely new associative table.
The foreign key step seems like it should be fairly simple, however given that
we are working with multiple tables rather than just two, makes it a bit more
difficult to understand exactly how to relate them. Hopefully moving forward
in the class it clarifies itself!!
RE:
Summary Conceptual Joelle Yule
Design
Process
7/29/2012 1:13:12 PM
Sean, I agree with the associative table. I feel a little like I'm
guessing too much. I am actually just looking for what the two other
tables might have in common. As for the keys though, I am simply
sticking to the primary keys for both will be the foreign key for the
table. I think this would ensure that it's all unique identifiers.
RE:
Summary Conceptual Kinja Cager
Design
Process
7/29/2012 8:43:35 PM
I find myself in the same situation, I feel like I'm guessing too much, I
might need a Tudor. Between the primary key and the related foreign
keys. I cant seem to get them to relate. Any suggestions?
RE:
Summary Conceptual Charlotte Hagans
Design
Process
7/29/2012 5:11:32 PM
This week has been a struggle for me in understanding how to
determine when to use a new table as well. I hope next week is
better.
RE:
Summary Conceptual Sara Floodberg
Design
Process
7/29/2012 6:01:27 PM
I think I have finally understood the concept of when to add
a junction table, but my problem is getting it to actually
working Access. I couldn't get my relationships to link
together other than 1:1.
RE:
Summary Conceptual Mark Ramsey
Design
Process
7/29/2012 7:55:15 PM
I would have to agree as i'm trying to play catch up on this weeks
project. The hardest part I was trying to wrap my head around as well
was exactly what FK/PK to applie and how to actually relate the
tables themselves.
Main
Question
Brittani Wigal
7/28/2012 9:51:35 PM
I think organizing data into tables and relationships are a good way to design a
database. I think this because having a database that is organized is easier to manage.
Having tables and relationships keep the information you need and you don't have to
search as much for the certain information you are looking for. I think that related
tables improve the accuracy of data in a database in a few ways. One would be the fact
that there is a primary key. Everything has to be a certain way before the database is
correct and it should show yo what errors you have. I hope I am right, I had a little
trouble answering this question.
How do
related
tables
improves
accuracy
database?
Caromill Almanzar
7/29/2012 9:09:58 PM
An effective Database design ensures that key aspects for a successful project
implementation are executed within expected time-lines that eventually lead to a costeffective approach during the project development phase.
Conceptual
Database
Sharon Gibson
7/29/2012 10:37:21 PM
Design
I’m not convinced that improve accuracy but, they do make it easier to
retrieve data and they make the amount of storage needed smaller. The user
sort through and organize large amounts of data. When the data is organized
in a systemic fashion, the data will be easier to work with.