BIT 200 FINAL STUDY GUIDE

• What is the difference between data and information: o Data is a set of discrete, objective facts about events. In an organizational context, data is most usefully described as structured records of transactions. o Information is a message to change the way the receiver perceives something to have an impact on his or her judgment or behavior.
• Ex. Your doctor tells you are on the verge of being obese. If you do not want to increase your risk of heart disease or diabetes, then you need to change your eating habits.
• What are the reference disciplines in information systems: o Computer Science- Computer Science is the discipline that seeks to build a scientific foundation for topics like computer design, computer programming, information processing, algorithmic solutions or problems, and the algorithmic process itself. o Management Science-The discipline using math and other analyzed methods to help make better decisions in business. Field includes- decision analysis, probability, and math modeling.
• Management Science body of knowledge – uses quantitative approaches to decision making and is referred to as management science, operations research, and decisions science.
• What do processors do: o A processor interprets computer program instructions and processes data.
• Moore’s Law- Moore’s Law state that processor speeds will double every 18 months
• The different kinds of storage memory are: kilobyte, megabyte, gugabyte, terabyte, petabyte, exabyte, and zeltabyte
• The difference between a bit and a byte are: o A bit is a single numeric value either a 0 or 1. A byte is a sequence of bits, usually 8 bit=1 byte. For example 00110101
• What are the components of an information system?
• An information system is a group of interdependent elements that transform data into information
• Data, people, hardware, software, databases, networks, information
• What is the difference between data and information?
• Data is raw material for data processing. Data relates to fact, event and transactions. Data refers to unprocessed information.
• Information is data that has been processed in such a way as to be meaningful to the person who receives it. It is any thing that is communicated
• What are the reference disciplines in information systems?
• Management (Org. Psych), Management Science (Statistics), and Computer Science (Mathematics)
• Know major milestones in the History of Computing.

o Hardware
• Review the hardware quiz you did at the beginning of the term
• What does a processor do?
• Microprocessor is the brain of the computing device. Executes the instructions of a computer program allowing it to run a web browser.
• The number of cores can distinguish different processors
• Volatile memory is data lost during a reboot. It is RAM. If your power goes out during a storm, the information that you were typing on your computer will not be saved. Nonvolatile memory is data saved to a hard drive or flash drive or it can be a hard coded chip. This is ROM. This is data saved when you shut your computer down.
• RAM (Random access memory) and disk storage both refer to internal storage space in a computer. RAM is a hardware that allows a computer to perform more than one task at a time efficiently. Disk storage refers to hard drive storage. Hard drive storage is typically used for long term storage of various types of files. High capacity hard drives can store large amounts of sizes of files such as videos, music, pictures, and documents.
• Operating System: An operating system manages the hardware and software resources. The operating system makes sure the application get the necessary resources it needs and providing users of applications get the most capacity it can. It’s second task is that it provides a consistent application interface. (LOOK AT OS on Ctools this was a definition from the web).
• Virtual memory combines your computers RAM with temporary space on your hard disk. When RAM runs low, virtual memory moves data from RAM to a space called a paging file. Moving data to and from the paging file fires up RAM to complete its work. RAM memory allows you to perform more than one task at a time on a computer ex. Writing a paper on Word and Listening to music.
• The difference between running a compiled program compared to running an interpreted program is compiled programs are faster for the user. If you make an interpreted program then the computer must read it and execute it (meaning it is slower). Programmers care about the difference because in compiled-they would have to make different programs for different operating systems and thus the instructions would be different.
• Two types of files stored on disks are data files and software. Data files are HTML (a brower). Programs are software.
• Open source software is a different way to develop and distribute software. It makes sure the source code (the language that a programmer writes) is available to anyone. It is free and no one has to pay for it. o Open source software examples:
• Operating systems-linux
• Office Applications-Open office (like Microsoft Office, Mediawiki, wordpress
• Database- MySQL
• Programming languages- PHP, Python
• Internet software-Firefox, Apache
It is possible to make money off open source software by selling support and related services, licensing the software for incorporation into commercial products.
• LAN vs. WAN: o LAN (Local Area Network)- local area networks are like a bus connection that supports many computers. It is generally inexpensive compared to WAN and has comparable speed. LAN spans short distances. o WAN (Wide Area Network)- WAN spans long distances, it is point to multipoint, generally more expensive than LAN and has comparable speed, it is depicted as a lightning bolt. Wolverine Access could be considered a WAN (I think).
-Ethernet ( a type of protocol is considered LAN)
• Components of a computer network: o 1) Computers—ex. Servers o 2) Networking hardware—Physical devices that control the flow of electromagnetic signals of the network media ex. Router, interface cord o 3) Media- intervening substance through which something else is transmitted ex. Twisted pair, optical fiber o 4) Communications software- Programs that control the transfer of data over a network ex. Windows 7, Novell o 5) Protocols- allowed and expected sequence of messages and their formation- ex. Ethernet o 6) Providers- Outside companies that provide pieces of a network ex. AT&T, Verizon o 7) Applications- the reason why we care about networks ex. Gmail, Microsoft Outlook
• Router and Switch- o Routers connect local area networks to the internet, they route and forward information, they are intelligent “active” devices o Switches link segments of LAN they control network traffic, “active” devices
• Examples of wireless media in LAN and related speed o Wired—twisted pair, less than or equal to 10 mega bits per second, coaxial cable, less than or equal to 200 mega bits per second o Wireless-Wifi o Mega bits per second (Mbps) is the “bandwidth”- the total number of bits that move from point A to point B in a time interval. Also referred to as data transmission rate.
• The largest WAN is the internet o Wireless media is WAN is WiMax—“last mile” wireless broadband access, runs up to 6 miles, communication satellites
• Switching—The most WAN media is owned by the phone companies (or other third party providers) eg. AT&T, Verizon o Two methods of switching used to make phone lines are: circuit switching and packet switching.
• Circuit switching is used for phone calls, leased lines for data communication. The characteristics of circuit switching are continuous transmission, dedicated circuit, the switch. Implications are that it can monitor transmission and determine length of transmission.
• Packet switching- a packet is a collection of bits that are part of a message plus other information (eg. Addresses)
-Router is hardware that moves packets.
-Characteristics include- intelligent transmission, stores and forwards information.
-Implications are: hard to monitor, hard to control, hard to keep track of the status of information. o Packet switching is a switching network that moves data in separate small blocks (packets) based on the destination address in each packet. When packets are received, they are reassembled in proper sequence to make up the message. Circuit switching requires dedicated point to point connections
-Packets are used to handle data while Circuits are used for phone calls
• The web is a collection of documents and applications accessible via the HTTP protocol. The Internet hosts the web plus-voice over IP, chat, streaming video or audio etc.
• The internet is a group of all computers connected around the world. The internet is bigger than the web.
• Key internet protocols o Internet protocols- IP, movement packets over internet based on IP address o Transmission errors are handled by TCP o Hypertext transport protocol-HTPP-it is for sharing documents over the internet
• Domain names are friendly names of internet servers (eg. www.umich.edu) is a domain name
Domain name servers maintains tables of domain names and related IP addresses and converts domain names into IP addresses -HTTP=protocol -edu=top level down -www.umich=sub domain -~ regoff=directory - index.html=file
• HTML is used to create websites=a standard system used for coding and creation of sites.
• Carrier sense multiple access with collision detection is the local area network assess method used in Ethernet. When a device wants to gain access to the network, it checks to see if the network is free.
• Cookies are small text files that contains a unique ID tag, placed on a users computer by a website. In the file, various information can be stored such as the pages you visit to information voluntarily given to the site (like your email or age when you sign up for something) o Ex. Twitter- if you go to a persons page—you can type their Twitter name into the URL space in the browser and it will show you the page.
• Compare and contrast application software and system software.
• System Software: OS- master control program, provides common functions that application software needs. Utilities- Support programs, used to maintain a computer system. Device drivers- handle communications with peripheral devices. Compilers/ interpreters- used to turn programming language statements into hardware instructions
• Application Software- provides tools tailored to perform a particular kind of task (Excel, PowerPoint, TurboTax, etc…)
• Why will all internet users eventually need to adopt IPv6?
• We are running out of IP addresses due to inefficient allocation of addresses and exploding number of interned connected devices
-IPv6 has 7.9*10^28 times as many addresses as IPv4
-Protocols are not compatible
• Client & Servers: o Client/Server are two computers working together to accomplish a goal. MAC or PC are clients while servers are over the network they are webpages for example. Server finds and sends the webpage while client shows you what the webpage looks like o Google docs is client/server example. Word is not a client server because it is not down over the internet. o Servers are the “boss” of the computer in charge of the network. Clients rely on resources controlled by the server. A large client database would be stored on the network server. Man client computers can access this data. EX. Excel and Access tutorials we do in class. The University of Michigan Ross School of Business owns the database. o Clients are an application system that accesses a remote service on a computer.
• Provide an example of client/server computing. Describe how a Web site serves as an example of client/server computing.
• Web services allow different applications to communicate with one another. Application Programming Interfaces (API’s) define the method to call a web service and the response back. Web services make it easier to link applications as distributed systems, and can make it easier for firms to link their systems across organizations.
• Southwest Airlines allows car rental and hotel firms to book services through Southwest. This process transforms Southwest.com into a full-service online travel agent.
• Client = browser. When you type a Web site’s address into the location field of your browser, you’re telling the client to “go find the Web server software at the address provided, and tell the server to return the Web site requested.”
• Software development life cycle is a series of steps or phases that provide a model for the development and lifecycle management of an application or piece of software. The purpose of the SDLC is to help produce a product that is cost effective, efficient, and high quality.
• Why does the cost to fix an error or make a change go up in the later stages of the SDLC?
• As you get closer to the deployment stage the cost of errors increases due to the amount of work that is required to go back and fix the problem. If a mistake is caught early then you can start over without many consequences. But if you are testing the product and find a fundamental flaw you must go all the way back and reanalyze the system and redesign it from the beginning.
• System development is a set of activities involved in moving from an idea for a new information software to having one that is actually in use by people in a company. o System development life cycle is the framework used by companies to organize information software projects. Life cycle starts with an idea and ends with replacing the old system with a new one “birth to death” ex. Tablets may one day replace laptops and desktop computers.
• System development methodology—a formalized, standardized, documented set of activities used to manage a system development project based on SDLC. o EX. Accenture NYC 311—a non-emergency communication system for people in New York City. o You plan, analyze, design, build, test, and deploy
• EX. Building a house—think about it (plan), specify it eg how many rooms, square footage (analyze), form blueprints (design), build the home (build), inspect the home (test), and you move in (deploy)
• Cloud computing is like client/server (you need this to have cloud). Cloud can do computational things like payroll, salesforce.com etc. You buy computing power from a network as opposed to buying software.
• Flat file to relational- insertion (adding records), updates (modifying existing rows), deletion, and anomalies. You get rid of these 4 problems when you convert from flat file to relational. o In one of the powerpoint lecture slides there is a slide that displays flat file and the slide after it shows relational. Look at these to understand what I am referring to here.
• If you delete a row in flat file- (ex. Chan does not want to be a client (if you delete his row all of GM’s stock is deleted as well which you did not want to delete).
• If you are updating-Lets says an individual moves from KC to CHI you have to change two places. If you change all KC to CHI those who did not move are messed up now. The extra computation takes time and money.
• If inserting- if you add stock without a person attached to the stock you will not be able to do it because you need a primary key with a person and stock.
• Normalization-third normal form due to separate things in separate tables (see relational slide).
• The differences between multi threading, multi tasking, and multi processing: o Single- 1 thing o Multi tasking- you have three different programs running like word, a web brower, and Spotify. The CPU can only execute one instruction at a time o Multi threading- could have 1 program running like Word and within it you have different components that do different things (such as editing, autosave etc. The threads can be executed at the same times.
• Harley-Davidson Case
• To help make its software decision, Harley used a scoring sheet with qualitative criteria, weights, and ratings. What was the value of this approach?
• This approach was helpful in determining what values were most important to the executives at Harley Davidson, and ultimately which consulting firm was the best based on the weighted criteria. Certain values were more important than others and this strategy helped identify which company is the best based on these different weights.
• Which provider did Harley choose and why?
• Provider 2 because of their functionality. However, their values did not line up with Harley Davidson’s
• Spreadsheets and Modeling: o The five fundamental uses of spreadsheets are to perform calculations, to record and organize data, to present data in easy to understand forms, to build models, and to perform simulations (eg. What if analysis) o A model is a presentation of a real object of system:
• There are physical models, mathematical models (analytical models, statistical models, financial models)
• Spreadsheet are tools for expressing a mathematical model and doing simulations with it
• “What if analysis”—change the inputs to obtain certain outputs --- the inputs involve calculations, rules and relationships. o Three kinds of what if analysis come with Excel: scenarios, data tables, and goal seek. Scenarios and data tables take sets of input values and determine possible results. A data table works only with one or two variables, but it can accept many different values for those variables. A scenarios can have multiple variables, but it can accommodate only up to 32 values. Goal seek works differently from scenarios and data tables in that it takes a result and determines possible input values that produce that result.
• Developing a spreadsheet model is similar to computer programming. (Think about it- not hard to know)
• What is a valid model: o Valid-logically correct o Valid argument- if the premise are true, then the conclusions will be true o Valid model- if the inputs represent reality, the outputs will represent reality o Model validation is important because when you create a spreadsheet you have determined assumptions/goals you want to achieve. The output will tell you if you are correct and creating reality. Ex. If I want to increase sales by $500,000 I believe buying new equipment will help me achieve this. When I factor is the cost etc. will the spreadsheet calculate a sales increase of $500,000. o In Excel, dates are sorted based on the serial number of the date, instead of on the displayed number. Therefore, when you sort dates in Excel, you may not receive the results you expect.
For example, if you sort a series of dates that are displayed in the mmmm date format (so that only the month is displayed), the months are not sorted alphabetically. Instead, the dates are sorted based on their underlying date serial number. o The fractional portion of the number, ttttt, represents the fractional portion of a 24 hour day. For example, 6:00 AM is stored as 0.25, or 25% of a 24 hour day. Similarly, 6PM is stored at 0.75, or 75% percent of a 24 hour day. o As you can see, any date and time can be stored as the sum of the date and the time. For example, 3PM on 19-Jan-2000 is stored internally as 36544.625. When you enter a time without a value, such as entering 15:00 into a cell, the date portion is a zero. The zero indicates that there is no date associated with the time. You should remember that entering just a time does not automatically put in the current date.

• Sensitivity analysis with Excel:
It is important to analyze the effects of different variables on an outcome, if they were to change. For example, what would be the effect on NPV if wages were to rise? At what range would the NPV change from positive to negative or vice versa? The answer to such queries can be formulated conducting a sensitivity analysis. In other words, try to determine how sensitive an outcome can be to changes in a specific variable.
The obvious method to conduct a sensitivity analysis is to enter different values into a spreadsheet model and determine the corresponding outcomes.
Microsoft Excel includes a table function that vastly simplifies the process of conducting a sensitivity analysis. When using the function, the computer determines the outcomes based on varying input values that is determined by the user.

For example, suppose we have a simply scenario where price is 10 and quantity is 100. The simulation model would be:

Price X Quantity = Sales
10 X 100 = 1000

If the price were to change from 8 to 12, the corresponding outcomes would be:
8 X 100 = 800
9 X 100 = 900
10 X 100 = 1000
11 X 100 = 1100
12 X 100 = 1200

In order to conduct the same analysis in Microsoft Excel, you must follow these steps: 1. Construct a model in excel where price and quantity are entered by the user, and the Sales is calculated by the formula Price * Quantity.
2. Construct a table area
3. Highlight the table area
4. Click on menu item Data, and then select Table.
5. You will be presented with a dialog box.
6. Click on Column Input Cell in Dialog Box
7. Locate and click on the Excel cell that has the price input value (A1 in diagram) 8. Click OK

• Absolute cell reference: formula=$A$1. The column letter A and the row number do not change.
• Cell Address- the cell identifier determined by its column letter(s) followed by the row # as in cell A1. The very first cell of each worksheet at the intersection of column A row 1. o Read about absolute and cell address online
• Naming cells and ranges in excel
1. Select the cell or cell range that you want to name.
You also can select noncontiguous cells (press Ctrl as you select each cell or range).
2. On the Formulas tab, click Define Name in the Defined Names group.
The New Name dialog box appears. Use the New Name dialog box to assign a name to the selected range.
3. In the Name text box, type up to a 255-character name for the range.
Range names are not case-sensitive; however, range names must follow these conventions:
• The first character must be a letter, an underscore, or a backslash.
• No spaces are allowed in a range name.
Then click Ok. Ranges:
To use a named cell or range, click the down arrow in the Name box at the left end of the Formula bar. Select the range name you want to access, and Excel highlights the named cells. You can select a range name in the Name box to quickly locate an area of a worksheet.
You also can use range names with the Go To dialog box, to make it easier to locate specific areas of a worksheet. Press F5 to display the Go To dialog box, select the range name you want to jump to, and click OK.
You can insert range names into formulas just like they were normal cell references. Be careful using named multi-cell ranges, though. Remember to use functions that require a range instead of a single cell reference — such as MAX, SUM, or AVERAGE — or else you'll get an error message.
• An Excel table is simply a set of rows and columns in a worksheet that contains related data and is displayed in a specific table format. If you have a large list of data, it's often useful to display that data in such a table. Not only does a table help you organize related data, it's also helpful for calculating values and displaying totals and grand totals.
• By using a table, you can more easily: o Manage and analyze data independently of data outside the table. o Apply one of many table formats to make data easier to view and scan o Add calculated columns to instantly calculate values o Use a Total row to quickly calculate and view totals o Filter data in table columns to display only data that you want to analyze
• A PivotTable is an interactive table that quickly summarizes large amounts of numeric data, which you can then analyze in detail. By using a PivotTable, you can more easily: o Display the exact data you want to analyze, make data comparisons, detect data patterns, relationships, and data trends.
• Goal Seek is a built in Excel tool that allows you to see how one data item in a formula impacts another. You might look at these as “cause and effect” scenarios. For example, you might be looking at your local election results and see: Votes % of Votes
YES 4478 63.90 *
NO 2530 36.10
Total 7008 100
* Needs approval from 2/3 of the voters
In our example, the YES votes are a majority, but shy of the required 2/3 approval to win the election. People quickly realize they were close, but which item do they change to find out how close. What would've made a difference?
Using Goal Seek we can change the value of various cells to see how the results change. This would allow you to answer these types of questions.
• How many “NO” voters needed to be converted to YES to win the election?
• How many more votes were needed by the YES team to win the election?
• If 500 more people voted could the YES team have won?
In each of these questions, the goal is to change a data value to see if the YES percentage went over that two-thirds mark or 66.67%.
• One-variable data tables Use a one-variable data table if you want to see how different values of one variable in one or more formulas will change the results of those formulas. For example, you can use a one-variable data table to see how different interest rates affect a monthly mortgage payment by using the PMT function. You enter the variable values in one column or row, and the outcomes are displayed in an adjacent column or row. o In the following illustration, cell D2 contains the payment formula, =PMT(B3/12,B4,-B5), which refers to the input cell B3. ________________________________________
• Two-variable data tables Use a two-variable data table to see how different values of two variables in one formula will change the results of that formula. For example, you can use a two-variable data table to see how different combinations of interest rates and loan terms will affect a monthly mortgage payment. o In the following illustration, cell C2 contains the payment formula, =PMT(B3/12,B4,-B5), which uses two input cells, B3 and B4.

• Input cells are cells in excel that you want to substitute
• Result cells show your configurations in the data table.
• Understand and be able to apply absolute and relative addressing in Excel.
• Relative- type a formula using the cell references (B2*C2), when you copy this formula and paste it in another cell, it will copy the relative locations of the cells. Good for copying and pasting functions that are generic and only need relative locations of the cells.
• Absolute- type a formula using the cell references and names (B2*C2*Multiplier) When pasted in another cell, it will take the relative locations of the cells and multiply them by the absolute reference to the shesmultiplier cell. Good for when you must multiply numbers by a certain value that is in a cell. Give the absolute cell a label and then include it in the formula.
• Understand how to name cells and ranges in Excel, and understand how to use the names in formulas.

o Excel Tables and Pivot Tables
• What is a structured range of data? What is it used for?
• Object records that contain data
• Used to track information about an object or topic
• What is an Excel table and why might you use one?
• Makes it easier to identify, manage, and analyze groups of data. Can be more productive with a table, and can reduce the chance of error. o Format, add new rows and columns, add total row, enter and copy formulas, create formulas and reference cells
• What is a pivot table and what does it enable you to do?
• Pivot tables help organize data into a meaningful summary, summarizes data into categories
• Takes a large amount of detailed data and puts it into a clear view of information
• Great way to summarize data from selected fields of an Excel table or range
• Enables readers to focus on the bigger picture
• Display values in different views
• Understand how to interpret the structure of data tables and PivotTables.
• Row labels- the fields that you want to display as the rows in the PivotTable. One row is displayed for each unique item in this area. You can have nested row fields
• Column labels- the fields yoso u want to display as columns at the top of the PivotTable. One column is displayed for each unique item in this area. You can have nested column fields
• A field used to filter the report by selecting one or more items, enabling you to display a subset of data in a PivotTable report
• The fields you want to summarize o What-If Analysis with Excel
• How do you do “what-if” analysis with Excel?
• Explore the impact of changing different variables in a worksheet
• Change the value of a worksheet cell (input cell), observe the impact on one or more calculated cells (result cells)
• Change projected values
• How do you do sensitivity analysis with Excel?
• Data tables
• What is a one-variable data table? Two variable data table? What is an input cell? A result cell?
• A one variable data table specifies one input cell and any number of result cells. Change a single variable and see the impact on several result cells
• In a two variable data table you can analyze a variety of combinations simultaneously by changing two variables. Two variable table shows the results of 36 what-if analyses on different conditions
• Input cell is the variable that will be changing in the analysis
• Result cell is the cell that takes into account the change in the input cell
• How might you use goal seeking? Be able to give an example?
• If you know the end number that you want to achieve you can goal seek to see the inputs necessary to achieve that goal
• Specify a value for a calculated item and Excel will return the input value necessary to achieve it
• How might you use scenario analysis? Be able to give an example.
• If you want to change certain values to see the impact on other components. Creating scenarios allows you to see how changes in certain values impact the big picture
• Databases, Database Design, and Access o Database Fundamentals
• What is a database? What is its purpose?
• a repository of structured business data
• Contains a large amount of data that people can access simultaneously
• What is a database management system? What are its components?
• Software for creating, maintaining, and manipulating data
• Handles storage of data on physical disk drives
• Makes it easier to manage large amounts of data
• Ex. Access, Oracle, DB2, MySQL

o Relational Databases
• Be able to identify all of the parts of a relational data table.
• Attribute- fields/data items
• Relation- table/file
• Primary key
• Attribute value
• Tuple- row/record
• Understand how relational tables “relate” to one another using keys.
• Tables relate to each other when they contain a common field
• Be able to define the terms field, record, table, relational database, primary key, and foreign key.
• Field- a single characteristic or attribute of a person, place, object, event, or idea
• Record- set of field values
• Table- collection of fields
• Relational database- collection of related tables
• Primary key- collection of fields, whose values uniquely identify each record in a table
• Foreign key- when the primary key from one table is included as a field in a second table to form a relationship between the two tables
• What is the defining characteristic of a composite primary key?
• A composite primary key is when two or more fields might be needed to function as the primary key
• What is the defining characteristic of a composite (or associative) entity, and how might one be used?
• Entity that associates the instances of one or more entity types and has attributes that are peculiar to the relationship between all of those entity instances
• Help combine multiple entities that do not have an attribute in common. Has the necessary primary keys to link the two entities o Database Design
• What types of problems are fixed by moving from a flat file structure to a relational structure? That is, understand the “anomalies” (related to data redundancy and dependencies).
• What is normalization? What’s the purpose?
• The process of ensuring that every field in a table depends on the key, the whole key, and nothing but the key
• Results in a database where facts are stored only once, easy to relate data in different tables, can ask ad hoc questions
• Understand the meaning of “Every field depends on the key, the whole key, and nothing but the key.”

o Entity-Relationship Diagrams
• What’s the purpose of building an ER diagram? Be able to convert an ER diagram into a database design.
• Tells you what tables you need in your database
• Tells you what primary keys you need
• Tells you what foreign keys you need
• Helps document the database for you, someone else, and for possible changes that have to be made
• What is a primary key? What is a foreign key?
• Primary key- collection of fields, whose values uniquely identify each record in a table
• Foreign key- when the primary key from one table is included as a field in a second table to form a relationship between the two tables
• Be able to define entity, attribute, and relationship as used in ER diagrams.
• Entity- a collection of things that have common properties or characteristics
• Attribute- named property or characteristic of an entity of interest to an organization
• Relationship- an association between instances of one or more entity types
• Be able to give examples of real-world situations involving data relationships that are 1:1, 1:M, and M:N
• 1:1- state:capital
• 1:M- patient: patient history
• M:N- Employee: course
• How do you implement a 1:M relationship in a relational database? How do you implement a M:N relationship?
• 1:M- just make a link between the primary key of one entity and an attribute (foreign key) in another entity. Add the primary key of the table on the 1 side of the relationship as an attribute (foreign key) of the table on the M side.
• M:N- must use a composite entity. Make 2 1:M relationships with the composite entity in the middle. Create a separate table where the primary key is a composite key consisting of the primary keys of the two tables (entities) in the relationship.
• Understand and be able to read schema notation.
• What is meant by the ”cardinality” of a relationship?
• Cardinality is the number of instances of one entity that are associated with on instance of a second entity

o Referential Integrity
• What is referential integrity? What might happen to a database if referential integrity were violated? Be able to give examples.
• A set of rules that access enforces to maintain consistency between related tables
• This prevents the possibility of orphaned records
• What are the rules that Access enforces to maintain referential integrity?
• Cant add a record to a related table unless a matching record exists in the primary table o Example: can’t add a contract for a customer unless the customer already exists
• Cant change the value of the primary key in a table if matching records exist in a related table o Example: can’t change a customer number if there are contracts recorded for that customer
• Cant delete a record in a table if matching records exist in a related table o Example: can’t delete customer 11031 if there are open contracts for him
• What is an orphaned record?
• A record whose matching record in either the primary or related table has been deleted

o Access
• What are the four types of Access objects that might be displayed in the navigation pane?
• Tables, queries, forms, reports
• What is an Access data type? Give three examples.
• The field property that determines what field values you can enter for the field and what other properties the field will have
• Text, memo, number, date/time, currency, yes/no, autonumber
• What is an Access form and what can you do with one?
• Use a form to enter, edit, and view records in a database. Can present data in many customized and useful ways
• What is an Access report?
• A formatted printout of the contents of one or more tables or queries in a database.
• What happens when you compact a database?
• Compacting the database rearranges the data and objects in a database to decrease its file size, thereby making more space available on your disk and letting you open and close the database more quickly o Queries and SQL
• What is a query?
• A question asked about the data in the database. Queries allow you to extract data from a collection of data tables based on certain criteria.
• What are two different ways of creating an Access query?
• Query by example- specify what you want by showing an example
• Query wizard- leads you through a series of questions to specify what you want
• In addition to retrieving data from a single table, what can you do with an Access query?
• Be able to read an Access query form and determine what information it would retrieve. Be clear about how “and” and “or” are implemented.
• What is the purpose of SQL? Be able to read and interpret a simple SQL statement.
• The standard language for defining and manipulating data in a relational database
• When you want to retrieve data from a relational database, you ask for it using SQL
• Select o From o Where
• Select price o From stock o Where price > 80
• What is a join?
• The process of relating tables using a common field