1. Introduction to Accounting Information Systems
Chapter 1
Chapter 5
Database
Management
Systems
Introduction to Accounting Information Systems

2. Learning Objectives
Understand techniques to model complex accounting phenomena in E-R diagram
Develop E-R diagrams that model effective accounting database structures
Recognize components of relational tables and keys to effective DB design
Understand use of SQL to create relational tables during implementation
Manipulate tables to extract data

3. Entities/Attributes
Entity - object, event, or agent about which data are collected
Objects - Inventory, equipment, cash
Events - Orders, sales, purchases
Agents - Customers, employees, vendors
Attribute - item of data that characterizes and entity or relationship

4. Attribute hierarchy for entity Client

5. Model representations for entities and attributes

6. Relationships

7. Constraints on data model relationships
EMPLOYEE
WORKS_COMPLETED 1
Works N
a. Cardinality constraints
EMPLOYEE
(1,1)
WORKS_COMPLETED
Works
(0,N)
b. Participation constraints

8. Relational Databases
Relation - collection of data representing multiple occurrences of an object, event, or agent.
Tuples (rows) - set of data that describe an instance of the entity represented by a relation; like a record in traditional file structure.
Attributes (columns) - items of data that characterize an object, event, or agent; like fields in traditional file structure.

9. Mapping E-R Diagram to Database
Create separate relational table for each entity.
Determine primary key for each relation. Must uniquely identify any row within table.
Determine attributes for each entity.
Implement relationships among entities. (Primary key in one table exists as attribute in every table (entity) where relationship specified in E-R.
Determine attributes, if any, for relationship tables.

10. Schema - billing & HR database
CLIENT
Client_No.
Name
Street_address
City
State
Zip_code
Contact
Phone_no
WORK_COMPLETED
Employee_No.
Date
Client_No.
Hours
EMPLOYEE
Employee_No.
Soc_Sec_No
Name
Supervisor_No
Billing_Rate
Pay_Rate
TRAINING_COMPLETED
Employee_No.
Date
Hours
Train_code
RELEASE_TIME
Employee_No.
Date
Hours
Vacation_Sick

11. Referential constraints - relational schema
CLIENT
Client_No.
Name
Street_address
City
State
Zip_code
Contact
Phone_no
WORK_COMPLETED
Employee_No.
Date
Client_No.
Hours
EMPLOYEE
Employee_No.
Soc_Sec_No
Name
Supervisor_No
Billing_Rate
Pay_Rate
TRAINING_COMPLETED
Employee_No.
Date
Hours
Train_code
RELEASE_TIME
Employee_No.
Date
Hours
Vacation_Sick

13. SQL : Relational DB Query Language
Used to
define database systems
query DB for information
generate reports from DB
access DB from within programs
De facto standard DB language

14. Constructing DBs using SQL
Assign name to relation
Assign names to attributes
Specify data type for attributes
Specify constraints, when appropriate, on the attributes.

15. Other SQL functions Update DB - Query DB using SELECT/WHERE
add tuple using INSERT
remove tuple using DELETE
change attribute value using UPDATE
Query DB using SELECT/WHERE
Generate standard reports from DB
ad hoc (as necessary)
repetitive - might generate subschema view

16. Learning Objectives
Understand techniques to model complex accounting phenomena in E-R diagram
Develop E-R diagrams that model effective accounting database structures
Recognize components of relational tables and keys to effective DB design
Understand use of SQL to create relational tables during implementation
Manipulate tables to extract data