DAY 16: ACCESS CHAPTER 1-2 Rahul Kavi October 8,

THINGS TO REMEMBER Any questions on grade will be answered at the end of the class. 10 points for each in-class project. It adds up to In-Class projects conducted (on Excel). Totals 50 points. 7 more In-Class projects will be conducted. If you submitted your in-class via (not with course tool), please see me after class. 2

BEFORE LAST LECTURE Introduction to Databases. Tables. Fields. What is a primary key? 3

LAST LECTURE Creating databases. Saving databases. Creating tables. Design tables. Modify tables. Set Primary key. Set a relationship. Import xml data. 4

IN-CLASS PROJECT Towards the end. 5

THINGS TO REMEMBER Microsoft Office tools help to visualize, understand the data. This course teaches both: Using Microsoft Office tools, help to answer questions on data. Through these tools, you understand data better. Your job is to answer the analysis questions. 20% of the points is for those answers. 6

EXAM FEEDBACK Your average exam score was: XX % Analysis Questions carry 20% of the grade. In exam, 80 points were for creating Excel sheet and formatting sheets, creating charts. 20 points were for answering the analysis questions. 7

EXAM FEEDBACK Read the question paper, don’t jump into doing the Excel sheet. Analyze created charts. Read question, given data to get answers to questions like Chart titles, axis titles, etc. Trend lines? Linear, Polynomial, Exponential. Two charts, not one. 6 points for formatting the analysis questions. 8

FEEDBACK Do the work on time. All Homework due on Fridays (time management). Getting help in open lab (Do your homework before doing homework in OpenLab). 9

TABLES: PRIMARY KEY The primary key uniquely identifies each record in a table. By default, tables have an ID field that is an autoincremented integer –The value of ID goes up by one for each new record. –Whenever a new record is entered, its count goes up by 1 (by default, you can change this behavior) 10

EXAMPLE OF PRIMARY KEY How to come up with a primary key? How do you uniquely identify something in a given data table? There can be no two entries with same value in a primary key. Name? (multiple people with same name) SSN? Student ID? ID? How do you uniquely identify a student based on given data (on paper)? WVU ID, Phone Number? 11

REFERENTIAL INTEGRITY (IDENTIFY COMMON FIELDS) Address Table PhoneNumber Table Use common field to create a relationship 12

RELATIONSHIPS: REFERENTIAL INTEGRITY Wikipedia: “Referential integrity is a property of data which, when satisfied, requires every value of one attribute (column) of a relation (table) to exist as a value of another attribute in a different (or the same) relation (table)”. 13

WHY DO WE NEED REFERENTIAL INTEGRITY? With referential integrity, we can relate fields in one table with fields in another table. Otherwise, Access will not know they are related. 14

QUERIES Asking question to a database? Ask right question for right answer. Retrieve stored data. 15

QUERIES Queries have “design view” and “data- sheet view”. Design views edits the queries Data-sheet view displays the result of the queries. 16

QUERY DESIGN Design a simple query. Question: What are all the division names, division ids, leagues in given data? Identify which fields are needed? Identify which fields are in which tables? If all required fields are in a single table, select fields from that table only. 17

STEPS TO WRITE A QUERY Close all windows (So that we don’t edit anything else and make sure everything is saved already to proceed to next step). Identify which fields are needed? Identify which fields are in which tables? If all required fields are in a single table, select fields from that table only. Select required fields from required tables in query design view. 18

STEPS TO WRITE A QUERY After design, click “Run” (in Query Did you get 6 records? If no, you got the wrong answer. 19

IN-CLASS PROJECT Get instructor approval before submitting files. Name file as “LastName_FirstName_1 st _Access_In- ClassProject” (no quotes). Download data files for today. Open instructions (pdf). Follow instructions. 20