- Data is often a company's most valuable asset and belongs in a data model that avoids anomalies like redundant data. - When building a database, identify required data fields, organize related fields into tables, and define primary keys and relationships between tables to avoid issues from updates, deletions, and insertions. - Normalization is the process of structuring data in tables to eliminate anomalies and ensure tables are in at least third normal form.

1. BSYS 2060 Lecture 2 – Data Literacy & Data Modeling

2. We live in an information age where data is king.

3. Data often most valuable asset of a company e.g. Aeroplan worth more than Air Canada

4. We live in a data mash-up world.

9. Where does data belong?

10. Diaspora Many “fly by night” Web 2.0 apps Self-hosted Website containing all your data You don’t control the data at all You control completely Not so easy... convenient Trend is towards you controlling your data

15. Who owns data?

17. Building a database for an organization?

18. What is the organization’s mission?

19. What is the project’s mission?

20. What data is required to make good decisions or for other reporting needs?

21. What data is currently being collected?

22. How is the data collected being used?

23. What data should be collected?

24. What are the main data entities? These will become your tables

25. What are the required fields and field data types?

26. What are the relationships between the tables?

27. Select your tools? e.g. MS Access, MS SQL, MySQL, Oracle What is being used now if anything?

28. Be careful of the hammer! To a hammer, everything looks like a nail. If you only know MS Access, you may see always see MS Access as the solution even when it’s not. If you only know MS Excel, it seems like the perfect choice! Source: http://www.flickr.com/photos/fixersphotos/3199566032/

29. Normalization A brief introduction to the first three forms...

30. “Normalization” In the field of relational database design, normalization is a systematic way of ensuring that a database structure is suitable for general-purpose querying and free of certain undesirable characteristics—insertion, update, and deletion anomalies—that could lead to a loss of data integrity. Codd, E.F. The Relational Model for Database Management: Version 2. Addison-Wesley (1990), p. 271

32. “...insertion, update, and deletion anomalies...” Until a Course Code is assigned to this record, it can not be inserted in the table

33. “...insertion, update, and deletion anomalies...” An edit made to one record may not be made to ALL records for the same employee

34. “...insertion, update, and deletion anomalies...” If the Course Code is deleted the information for the Faculty Member will be lost.

35. Three Normal Forms 1NF Eliminate repeating groups No redundant data 2NF Eliminate independent data All fields depend on Primary Key 3NF Eliminate dependency on non-key fields Fields do not depend on each other

36. Un-Normalized Table (i.e. Excel)

37. First Normal Form (1NF) 0NF – “un-normalized” 1NF

38. Second Normal Form (2NF) 1NF 2NF

39. Third Normal Form (3NF) 2NF 3NF

40. Access Tutorial 2Building a Database and Defining Table Relationships

41. Objectives Learn the guidelines for designing databases and setting field properties View and modify field data types and formatting Create a table in Design view Define fields and specify a table’s primary key Modify the structure of a table New Perspectives on Microsoft Office Access 2007 41

42. Objectives Import data from an Excel worksheet Create a table by importing an existing table structure Delete, rename, and move fields Add data to a table by importing a text file Define a relationship between two tables New Perspectives on Microsoft Office Access 2007 42

43. Guidelines for Designing Databases Identify all the fields needed to produce the required information Organize each piece of data into its smallest useful part Group related fields into tables Determine each table’s primary key Include a common field in related tables Avoid data redundancy Determine the properties of each field New Perspectives on Microsoft Office Access 2007 43

44. Guidelines for Setting Field Properties You must name each field, table, and other object Choose an appropriate data type New Perspectives on Microsoft Office Access 2007 44

45. Guidelines for Setting Field Properties The Field Size property defines a field value’s maximum storage size for Text, Number, and AutoNumber fields only Byte Integer Long Integer Single Double Replication ID Decimal New Perspectives on Microsoft Office Access 2007 45

46. Viewing and Modifying Field Data Types and Formatting New Perspectives on Microsoft Office Access 2007 46

47. Creating a Table in Design View New Perspectives on Microsoft Office Access 2007 47

48. Defining a Field in Design View In the Field Name box, type the name for the field, and then press the Tab key Accept the default Text data type, or click the arrow and select a different data type for the field. Press the Tab key Enter an optional description for the field, if necessary Use the Field Properties pane to type or select other field properties, as appropriate New Perspectives on Microsoft Office Access 2007 48

49. Defining a Field in Design View New Perspectives on Microsoft Office Access 2007 49

50. Specifying the Primary Key in Design View In the Table window in Design view, click in the row for the field you’ve chosen to be the primary key. If the primary key will consist of two or more fields, click the row selector for the first field, press and hold down the Ctrl key, and then click the row selector for each additional primary key field In the Tools group on the Table Tools Design tab, click the Primary Key button New Perspectives on Microsoft Office Access 2007 50

51. Specifying the Primary Key in Design View New Perspectives on Microsoft Office Access 2007 51

52. Moving a Field To move a field, you use the mouse to drag it to a new location in the Table window in Design view New Perspectives on Microsoft Office Access 2007 52

53. Adding a Field Between Two Existing Fields In the Table window in Design view, select the row for the field above which you want to add a new field In the Tools group on the Table Tools Design tab, click the Insert Rows button Define the new field by entering the field name, data type, optional description, and any property specifications New Perspectives on Microsoft Office Access 2007 53

54. Adding a Field Between Two Existing Fields New Perspectives on Microsoft Office Access 2007 54

55. Importing Data from an Excel Worksheet The import process allows you to copy the data from a source without having to open the source file Click External Data on the Ribbon Click the Excel button in the Import group to start the wizard New Perspectives on Microsoft Office Access 2007 55

56. Importing Data from an Excel Worksheet New Perspectives on Microsoft Office Access 2007 56

57. Importing Data from an Excel Worksheet New Perspectives on Microsoft Office Access 2007 57

58. Importing Data from an Excel Worksheet New Perspectives on Microsoft Office Access 2007 58

59. Creating a Table by Importingan Existing Table Structure Make sure the External Data tab is the active tab on the Ribbon In the Import group, click the Access button Click the Browse button Navigate to the file Make sure the Import tables, queries, forms, reports, macros, and modules into the current database option button is selected, and then click the OK button Click the Options button New Perspectives on Microsoft Office Access 2007 59

60. Creating a Table by Importingan Existing Table Structure New Perspectives on Microsoft Office Access 2007 60

61. Deleting a Field from a Table Structure In Datasheet view, select the column heading for the field you want to delete In the Fields & Columns group on the Datasheet tab, click the Delete button or In Design view, click in the Field Name box for the field you want to delete In the Tools group on the Table Tools Design tab, click the Delete Rows button New Perspectives on Microsoft Office Access 2007 61

62. Deleting a Field from a Table Structure New Perspectives on Microsoft Office Access 2007 62

63. Adding Data to a Table by Importing a Text File Click the External Data tab on the Ribbon In the Import group, click the Text File button Click the Browse button Navigate to the file Click the Append a copy of the records to the table option button Select the table Click the OK button New Perspectives on Microsoft Office Access 2007 63

64. Adding Data to a Table by Importing a Text File New Perspectives on Microsoft Office Access 2007 64

65. Defining Table Relationships One of the most powerful features of a relational database management system is its ability to define relationships between tables You use a common field to relate one table to another New Perspectives on Microsoft Office Access 2007 65

66. Defining Table Relationships New Perspectives on Microsoft Office Access 2007 66

67. Defining Table Relationships A one-to-many relationship exists between two tables when one record in the first table matches zero, one, or many records in the second table, and when one record in the second table matches at most one record in the first table The Primary table is the “one” in a one-to-many relationship The Related table is the “many” table New Perspectives on Microsoft Office Access 2007 67

68. Defining Table Relationships Referential integrity is a set of rules that Access enforces to maintain consistency between related tables when you update data in a database The Relationships window illustrates the relationships among a database’s tables Click the Database Tools tab on the Ribbon In the Show/Hide group on the Database Tools tab, click the Relationships button New Perspectives on Microsoft Office Access 2007 68

69. Defining Table Relationships New Perspectives on Microsoft Office Access 2007 69

70. Defining Table Relationships New Perspectives on Microsoft Office Access 2007 70

71. Defining Table Relationships New Perspectives on Microsoft Office Access 2007 71