1 1 0 0 0 0 0 0 1 1 C:\Documents and Settings\james\My Documents\millerjwcom\dom\gbis722online\week3\Chap08aSummary\Chap08aSummary.avi 0 0 0 1110000000 1 32 1024 768 3706000000 0 2596000000 0 1110000000 10.000000 1.000000 2 4478 65 1 22050 0 49 0 Sample Entity Relationship Diagram (ERD) 1 C:\Documents and Settings\james\My Documents\millerjwcom\dom\gbis722online\week3\Chap08aSummary\Chap08aSummary.avi 0 1 1110000000 1521000000 1 32 1024 768 3706000000 1110000000 2185000000 1110000000 1521000000 10.000000 1.000000 2 4478 65 1 22050 0 49 1 Data Modeling Concepts: Entity 1 C:\Documents and Settings\james\My Documents\millerjwcom\dom\gbis722online\week3\Chap08aSummary\Chap08aSummary.avi 0 2 1521000000 1833000000 1 32 1024 768 3706000000 1521000000 1873000000 1521000000 1833000000 10.000000 1.000000 2 4478 65 1 22050 0 49 2 Data Modeling Concepts: Entity 1 C:\Documents and Settings\james\My Documents\millerjwcom\dom\gbis722online\week3\Chap08aSummary\Chap08aSummary.avi 0 3 1833000000 1971000000 1 32 1024 768 3706000000 1833000000 1735000000 1833000000 1971000000 10.000000 1.000000 2 4478 65 1 22050 0 49 3 Data Modeling Concepts: Attributes 1 C:\Documents and Settings\james\My Documents\millerjwcom\dom\gbis722online\week3\Chap08aSummary\Chap08aSummary.avi 0 4 1971000000 2379000000 1 32 1024 768 3706000000 1971000000 1327000000 1971000000 2379000000 10.000000 1.000000 2 4478 65 1 22050 0 49 4 Data Modeling Concepts: Data Type 1 C:\Documents and Settings\james\My Documents\millerjwcom\dom\gbis722online\week3\Chap08aSummary\Chap08aSummary.avi 0 5 2379000000 2614000000 1 32 1024 768 3706000000 2379000000 1092000000 2379000000 2614000000 10.000000 1.000000 2 4478 65 1 22050 0 49 5 Data Modeling Concepts: Domains 1 C:\Documents and Settings\james\My Documents\millerjwcom\dom\gbis722online\week3\Chap08aSummary\Chap08aSummary.avi 0 6 2614000000 2776000000 1 32 1024 768 3706000000 2614000000 930000000 2614000000 2776000000 10.000000 1.000000 2 4478 65 1 22050 0 49 6 Data Modeling Concepts: Default Value 1 C:\Documents and Settings\james\My Documents\millerjwcom\dom\gbis722online\week3\Chap08aSummary\Chap08aSummary.avi 0 7 2776000000 2990000000 1 32 1024 768 3706000000 2776000000 716000000 2776000000 2990000000 10.000000 1.000000 2 4478 65 1 22050 0 49 7 Data Modeling Concepts: Identification 1 C:\Documents and Settings\james\My Documents\millerjwcom\dom\gbis722online\week3\Chap08aSummary\Chap08aSummary.avi 0 8 2990000000 3130000000 1 32 1024 768 3706000000 2990000000 576000000 2990000000 3130000000 10.000000 1.000000 2 4478 65 1 22050 0 49 8 Data Modeling Concepts: Cardinality 1 C:\Documents and Settings\james\My Documents\millerjwcom\dom\gbis722online\week3\Chap08aSummary\Chap08aSummary.avi 0 9 3130000000 3703000000 1 32 1024 768 3706000000 3130000000 3000000 3130000000 3703000000 10.000000 1.000000 2 4478 65 1 22050 0 49 9 Cardinality Notations 1 0 Sample Entity Relationship Diagram (ERD) 1 0 1110000000 Data Modeling Concepts: Entity 1 1 1521000000 Data Modeling Concepts: Entity 1 2 1833000000 Data Modeling Concepts: Attributes 1 3 1971000000 Data Modeling Concepts: Data Type 1 4 2379000000 Data Modeling Concepts: Domains 1 5 2614000000 Data Modeling Concepts: Default Value 1 6 2776000000 Data Modeling Concepts: Identification 1 7 2990000000 Data Modeling Concepts: Cardinality 1 8 3130000000 Cardinality Notations 1 9 32 0000 Teaching Notes Be sure to explain that this is merely an example – there are 370000000 numerous data modeling notations. While they may differ in appearance 740000000 (symbology) the knowledge that data models are intended to convey the same. 1110000000 Teaching Notes: Prompt the students for additional examples. Have them 1212750000 classify their example(s). Obtain a data model from a source other than the textbook. 1315500000 Ask the students to classify the entities. 1418250000 1521000000 Teaching Notes Substitute the name(s) of one or more of your students. 1625000000 Be sure to explain that these are “instances” and that instances do NOT appear in the 1729000000 names of entity symbols. 1833000000 Teaching Notes: Go back to the slide showing the sample ERD (Figure 8-1). Pick 1853000000 an entity and ask the students to list attributes that they feel describe those entities. 1873000000 Show the students a form. Ask the students to identify the attributes. Be sure that the 1893000000 students recognize what items appearing on the form are truly attributes and those that are 1913000000 simply headings or preprinted items. Also, often students accidentally identify attribute 1933000000 values as attributes. For example, they may say that an item that appears as a check 1953000000 box is an attribute when in fact it may be the value of an attribute (ie. Male and female are values, whereas GENDER is the real attribute). 1971000000 Teaching Notes These are generic data types. If your students have taken a 2175000000 database class they would be familiar with the data types specific to that database. 2379000000 No additional notes 2614000000 No additional notes 2776000000 Teaching Notes Students can generally relate to the following example. Suppose 2806570000 you are working for an hourly wage. The employer has some method of tracking the hours 2837140000 you work. Whether that involves a time clock, an identification badge that it scanned, or a log 2867710000 book, the system records a certain number of hours and some employee identifier that 2898280000 says those hours are yours. Without that identifier, come pay day the employer would not 2928850000 know whose hours were whose. The employer might pay someone else for the hours you worked. 2959420000 That’s how important a primary key or identifier is. 2990000000 Teaching Notes Ask the students to read (or write) declarative sentences to 3060000000 reflect the bidirectional meaning of the relationship between student and curriculum. 3130000000 Teaching Notes Although this figure shows five different options, help students 3321000000 see that there are really only two options for minimum cardinality (0 or 1) and two 3512000000 options for maximum cardinality (1 or many).