1. INFSY540 Information Resources in Management Lesson 6 Chapter 5 Database Management

2. Slide 2 Portfolio and Ecommerce HTML Assignment Assignment is on course web space at http://www.courses.psu.edu/infsy/infsy540/rak13/ HTML_Portfolio.html Part of the assignment is to do research on ecommerce. The first version of your portfolio.html page and subsequent sections of your site must be posted by the October 31st class. The final site must be online by November 28. –There are individual and team activities that need to take place between these times.

3. Slide 3 Case 2: Cisco Systems Architecture What’s this case about? When did Cisco go public? What does Cisco stand for? What is Cisco’s mission? IT Interaction Model http://equity.stern.nyu.edu/~msilver/mbacore/itimhdo.htm

4. Slide 4 Learning Objectives Know the difference between a database and a spreadsheet. Identify the objects available in a relational database and their purpose. Know the difference between a query and a filter. Identify typical problems that occur with MS Access and other “personal” vice “enterprise” databases.

5. Slide 5 Shared Data Poorly organized data prevents sharing that data with other “databases” Think of all the “databases” that lists your name, department, etc.: Messiah College Phone List Database Students Using College Networked Computers Students Using Dining Facility Students Using Nursing Facility

6. Slide 6 Database Management System Computer program designed to help a user store and retrieve data –Access, Oracle, DB2

7. Slide 7 abcd 1234 defg 12 asd 123 kghb 112 abcd 1234 defg 12 asd 123 kghb 112 abcd 1234 123 asd 123 12 kghb 112 34 DBMS abcd 1234 defg 12 asd 123 kghb 112 tables forms query abcd 1234 defg 12 asd 123 kghb 112 abcd 1234 123 asd 123 12 kghb 112 34 reports labels Data Dictionary Outside Applications DBMS Engine attached import

8. The Traditional versus the Database Approach to Data Management

9. Slide 9 Fig 5.3

10. Slide 10 Problems with the “Traditional” Approach Data redundancy Program-data dependence Inflexibility

11. Slide 11 Fig 5.4

12. Data Modeling & Database Models

13. Slide 13 Data Design Issues Content: What data should be collected? Access: What data should be given to what users? Logical structure: How will the data be organized to make sense to a particular user? Physical organization: Where will the data actually be located?

14. Slide 14 Data Modeling Logical design Physical design Planned data redundancy Data model

15. Slide 15 Data Models Hierarchical models Network models Relational models

16. Slide 16 Fig 5.6

17. Slide 17 Fig 5.7

18. Slide 18 Fig 5.8

19. Slide 19 Operations Select rows Project columns Join tables

20. Slide 20 Fig 5.9

21. Slide 21 Object-Relational Database Management Systems Stores objects Hypertext Hypermedia Spatial data technology

22. Slide 22 Database Management Systems (DBMSs) Provide a user view Provide tools to create & modify the database Store & retrieve data Manipulate data Produce reports

23. Slide 23 Selecting a DBMS Number of concurrent users Database size Performance Integration Features Vendor Cost

24. Slide 24 Database Developments Data warehouses Data marts Data mining Online analytical processing (OLAP)

25. Slide 25 What Is a Database? Database: Table: Record: Field:

26. Slide 26 What Is a Database? Database: a collection of data Table: the primary element for collecting data, organized into rows and columns Record: an individual entry in a table (row) Field: a piece of data in a record (column)

27. Slide 27 Access97: A Database Example Field (column) Record (row) Table

28. Slide 28 Access Database Objects Table: Query: Form: Report: Macro/Module:

29. Slide 29 Access Database Objects Table: Used to store and manipulate data. Query: Used to retrieve information. Form: Used to view one record of data. Report: Used to present, calculate, summarize, and print table data. Macro/Module: Used to automate frequently performed procedures.

30. Slide 30 The database window is the command center; it provides the means to create, view, and edit database objects, such as tables, forms, and reports. Control icon Object tabs Processing or Command Buttons

31. Slide 31 What is the difference between a database and a spreadsheet?

32. Slide 32 Use Microsoft Excel to analyze financial and statistical data. Excel Spreadsheet

33. Slide 33 Use Microsoft Access to create, maintain, and summarize very large quantities of data. Access Database

34. Slide 34 Why do “databases” in spreadsheets? Because we can We use 1 or 2 massive tables –“Lots of tables make the database complex” –Discomfort with databases and multiple tables Because we “think it’s simple” –Skip organizing the data into relational tables –Go straight to designing forms NAME POSITIONSPOUSECHILDRENPHONE JonesChiefGloria,Karen3274 SmithClerkBetty3241 JonesChiefMary Glorai, Karen3296

35. Slide 35 Data Redundancy Problems Redundancy breeds errors –Same data defined in multiple places is BAD –Spelling/typographical error prone –Lack of data integrity Inability to perform simple queries Inflexibility and inscalability Impossible to MAINTAIN!

36. Slide 36 Relational Database PROJECTCHIEF Project Project Chief Computing 333-22-1111 Intranet 987-65-4321 Contracting 123-45-6789 Jordan 333-22-1111 DEPARTMENTS DeptDept. DirectorRoom Engr181-94-5676B115 Math987-65-4321123 M&B123-45-6789147 EMPLOYEES LNameFNameSSN Dept JonesMike123-45-6789 M&B SmithTony987-65-4321 Math LeeBruce 567-89-1234 Engrr DoodleYankee333-22-1111 M&B 1 1

37. Slide 37 Example Employee SSN L Name F Name Rank Spouse Children Office Phone# Home Phone# Office Room# Dept Dept. Chief EmpProj Project Name Employee SSN Function Must know all constraints on data –project name is unique –only one chief per project –employees can have more than one phone# –employees can have only one office –many employees can use the same office

38. Slide 38 Just a Reminder A table is a single object within a database A database can have other objects such as queries, forms, reports, macros, and programming modules However, at least one table object must be created before you can create any other type of object

39. Slide 39 Database Design Templates CHOOSE: File, New Database or CLICK: New Database button Design Templates

40. Slide 40 Using Datasheet View (Usually used for entering data into records) Using the Table Wizard (Usually used for creating tables) Using Design View (Usually used for creating tables and editing fields) How Do I Create a Table? Sample Table in Datasheet View

41. Slide 41 Using the Table Wizard Pick fields from existing business and personal table structures

42. Slide 42 Using Design View Specify field names, data types, and indexes from scratch Define fields and data types Define field properties Note: Fields are shown in rows in the design view, not in columns.

43. Slide 43 Field Data Types Text Memo Number Date/Time Currency Autonumber Yes/No OLE Object Hyperlink Lookup Wizard

44. Slide 44 Field Properties Field Size Format Decimal Places Input Mask Caption Default Value Validation Rule Validation Text Required Allow Zero Length Indexed

45. Slide 45 Primary Keys (Are extremely important in databases.) Primary key is a field that uniquely identifies each record in a table –Data is automatically displayed in the datasheet sorted by the primary key. –There are 3 types of primary keys: AutoNumber, Single-Field, and MultiField. –You can use Access AutoNumber as a primary key (since it is unique) but it is not a good idea. CHOOSE: Edit, Primary Key or CLICK: Primary Key button

46. Slide 46 Primary Keys A primary key is one or more data fields (columns) that uniquely identify each record in the table What would the primary key be below? –“table of employees, assigned to a department.” EMPLOYEES LNameFNameSSNDept JonesMike123-45-6789Math SmithTony987-65-4321 M&B LeeBruce 567-89-1234Science

47. Slide 47 Indexes Like Primary Key, can be used to determine the order in which data is displayed CLICK: Indexes button Primary Key Index Definition Indexes can slow down data entry. Access automatically creates indexes for fields with ‘ID’ in their names.

48. Slide 48 Access Uses Automatic Saving CLICK: a cell using the mouse pointer Make changes to the cell’s information. SELECT: another record to save the changes CHOOSE: Edit, Undo from the menu if you want to reverse the most recent changes Note: This is a very important difference between Access and other Office 2000 products..

49. Slide 49 Customizing Datasheet View Remember: formatting changes are not saved automatically. Only structural and data changes are saved automatically.

50. Slide 50 Adjusting Column Widths DRAG: the column border between the field names at the top of the window DOUBLE-CLICK: the column border to have Access calculate the “best-width” Column Borders

51. Slide 51 Adjusting Row Heights DRAG: the border between rows to change all row heights in the datasheet Row Borders

52. Slide 52 Reordering Fields SELECT: the entire field column DRAG: field name to move the column To save the Datasheet view: CLICK: Save button

53. Slide 53 Sorting Records Allows you to better organize and present data; makes information out of raw data (alphabetical phone listing) SELECT: column or field to sort CLICK: Sort Ascending button CLICK: Sort Descending button

54. Slide 54 Filters Lets you limit the display of records in a table using a simple matching criterion Methods for filtering data:  Filter For Input  Filter By Selection  Filter Excluding Selection  Filter By Form  Advanced Filter/Sort

55. Slide 55 What Is a Query? A query is a question you ask of your database –How many customers live in Chicago? –What is the average age of our employees? There are two types of queries –Select queries let you retrieve information –Action queries let you modify information

56. Slide 56 Queries versus Filters Although similar to filters, queries provide additional functionality: –you can display data from multiple tables –you can control which fields display –you can perform calculations on field values While filters are temporary, queries are saved as independent database objects

57. Slide 57 Query Design Window A graphical query-by-example tool. Displays tables on which you’ve chosen to base your query Displays the grid that you use to specify your criteria and sorting options

58. Slide 58 Query Grid Area Field: used to add a field to the grid Table: used to clarify the field’s table Sort: used to sort the resulting table Show: used to hide or show the field Criteria: used to set the query criteria Or: used to specify a second criterion

59. Slide 59 Specifying a Search Criteria Enter an example of value you are searching for in the Criteria row Use the question mark (?) wildcard to represent a single unknown character Use the asterisk (*) wildcard to represent more than one character Use operators (, =) to limit records between a range of values or dates

60. Slide 60 Examples of Search Criteria Like Sm?th returns records with Smyth and Smith Like Ch*ng returns records with Chang and Chickering Between 21 And 65 returns records with values from 21 to 65 <=98000 returns values of less than or equal to 98000

61. Slide 61 How Do I Create a Form? Using the AutoForm Wizard Using Design View A form created using the AutoForm Wizard Form Navigation Controls

62. Slide 62 What Is a Report? An on-screen or printed display of organized data from a table Examples include: sales summaries, invoices, mailing labels, personal address books, and inventory listings Report Title NameAddressPhone

63. Slide 63 AutoReport: Columnar Created using the AutoReport Wizard. Field Names Table Data

64. Slide 64 AutoReport: Tabular Created using the AutoReport Wizard. Field Names Table Data

65. Slide 65 Questions to consider when designing a DataBase Who will use it? What type of tasks? What are the data sources? What output is required?

66. Slide 66 Data Modeling Determine Data Requirements Entity Class something that can be identified in environment each entity class is a separate table each entity becomes a separate row in a table Attributes property or characteristic of entity each characteristic of an entity class become a column each characteristic of an entry become an entry in table Keys one or more attributes that uniquely identified an entity Constraints values or rules the DBMS must enforce

67. Slide 67 Designing a Database  Determine your output requirements  Design your database on paper first  Divide information into separate fields  Divide information into separate tables  Identify each record with a unique code  Place important fields at top of structure  Test your database

68. Slide 68 Access Lab and Assignment If not familiar with Access, then go to lab and on course web space do either Access 97 or Access 2000 tutorials. –access_tutorial_2000.html –access_tutorial_97.html Try doing exercises 1-5 and 20-25 on page 205 and 206 using c05Ex15.mdb and Rolling Thunder Database from student CD (or from G:\Courses\Infsy540). Database Assignment will be on course web space next week –dbms_assignment.html –Due by beginning of class on Oct 17th

69. Slide 69 Questions?