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TM 6-TM 6-11Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Logical Database Design andthe Relational Database
Professor Chen
School of Business Administration
Gonzaga University
Spokane, WA 99258
TM 6-TM 6-22Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
What is a Relation?
• A relation is a named, two-dimensional table of data.
• Each relation consists of a set of named columns and an arbitrary number of unnamed rows.
• Not all table are relations
TM 6-TM 6-33Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-1: EMPLOYEE1 Relation with sample data
EMPLOYEE1
Emp_ID Name Dept_Name Salary
100 Margaret Simpson Marketing 48,000140 Allen Beeton Accounting 52,000110 Chris Lucero Info. System 43,000190 Lorenzo Davis Finance 55,000150 Susan Martin Marketing 42,000
TM 6-TM 6-44Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Relational Definitions
• Relation– Every relation has a unique name.– Every attribute value is atomic (singled-value)
(Fig. 6-1)– Every row is unique.– Attributes in tables have unique names.– The order of the columns is irrelevant.– The order of the rows is irrelevant.
TM 6-TM 6-55Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-2: Eliminating multi-valued attributes
(a) Table with repeating groups (Un-Normalized)
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed
100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X Java 8/12/199X
TM 6-TM 6-66Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X Java 8/12/199X
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X100 Margaret Simpson Marketing 48,000 Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X110 Chris Lucero Info. System 43,000 C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X150 Susan Martin Marketing 42,000 Java 8/12/199X
TM 6-TM 6-77Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-2: Eliminating multi-valued attributes
(b) EMPLOYEE2 Relation (Normalized)
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed
100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X100 Margaret Simpson Marketing 48,000 Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X110 Chris Lucero Info. System 43,000 C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X150 Susan Martin Marketing 42,000 Java 8/12/199X
EMPLOYEE2
TM 6-TM 6-88Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Relational Keys and Structures
• Primary Key
• Composite Key
• Foreign Key– One-to-Many Relationship– Many-to-Many Relationship
• Intersection Data
• Candidate Key
• Surrogate Key
TM 6-TM 6-99Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-3: Schema for four relations (Pine Valley Furniture) Graphical Representation
TM 6-TM 6-1010Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-3: Schema for four relations (Pine Valley Furniture) Graphical and Text Representations
CUSTOMER(Customer_ID,Customer_name,Address,City,State,Zip)
ORDER(Order_ID,Order_Date,Customer_ID)
ORDER_LINE(Order_ID, Product_ID,Quantity)
PRODUCT(Product_ID,Product_Description,Product_Finish,Unit_Price,On_Hand)
TM 6-TM 6-1111Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Integrity Constraints
• Domain Constraints– Allowable values for an attribute.– A domain definition contains: domain name, data
type, size, meaning, and allowable values/range (if applicable).
• Entity Integrity– No primary key attribute may be null.
• Operational Constraints– Business rules (see Chapter 4)
TM 6-TM 6-1212Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-5: Referential integrity constraints (Pine Valley Furniture)
pk
pk
ck/pk
pk
fk
fkfk
TM 6-TM 6-1313Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
CUSTOMER
Customer_ID Customer_Name Customer_Address
123 John Smith S. 34 Freya, Spokane345 Allen Stone 45 A St. Cheney489 Mary Jones E. 21 Trent, Spokane789 Kent Watson 23 Y Ave. Spokane…
Referential Integrity (Addition and Deletion)
PK
ORDER
Order_ID Order_Date Customer_ID
OR-002 9/21/1998 123OR-003 9/30/1998 345OR-004 10/1/1998 123OR-004 10/2/1998 489… 642
FK
TM 6-TM 6-1414Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Referential Integrity (Summary)
• Addition - you can’t add (insert) an ORDER record if Customer_ID (FK) does not exist (or does not match) a Customer_ID (PK) in the CUSTOMER table.
• Deletion - you can’t delete a CUSTOMER record if there is (are) related Customer_ID in the ORDER table.
TM 6-TM 6-1515Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Integrity Constraints
• Referential Integrity– A rule that states that either each foreign key
value must match a primary key value in the other relation or else the foreign key value must be null.
– For example: Delete Rules• Restrict
• Cascade
• Set-to-Null
TM 6-TM 6-1616Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Referential Integrity (Conclusion)CUSTOMER
Customer_ID Customer_Name Customer_Address
123 John Smith S. 34 Freya, Spokane345 Allen Stone 45 A St. Cheney489 Mary Jones E. 21 Trent, Spokane789 Kent Watson 23 Y Ave. Spokane…
ORDER
Order_ID Order_Date Customer_ID
OR-002 9/21/1998 123OR-003 9/30/1998 345OR-004 10/1/1998 123OR-004 10/2/1998 489… 642
common fieldfk
pk
pk
TM 6-TM 6-1717Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Referential Integrity (Conclusion)
TABLE-1(CUSTOMER)
TABLE-(ORDER)
RULES:
1. You can’t add a record to TABLE- (or the table with fk) unless there is a corresponding record in TABLE-1 (or the
table with pk).
2. You can’t delete a record in TABLE-1 (or the table with pk) ifthere is a record in TABLE- (or the table with fk).
TM 6-TM 6-1818Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Referential Integrity (Conclusion)
STUDENTpk fk
SID SLNAME … SPIN FID100 Miller 8891 1… …
105 Connoly 9188 3
FACULTY pk fk
FID FLNAME … LOCID … FPIN1 Cox 53 1181… … …5 Brown 57 9899
LOCATION pkLOCID BLDG_CODE ROOM CAPACITY
45 CR 101 150… …57 LIB 222 1
TM 6-TM 6-1919Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Referential Integrity (Conclusion)
TABLE-1 TABLE- (FACULTY) (STUDENT)
RULES:
1. You can’t add a record to TABLE- (or the table with fk,e.g., STUDENT) unless there is a corresponding record inTABLE-1 (or the table with pk).
2. You can’t delete a record in TABLE-1 (or the table with pk,e.g., FACULTY) if there is a record in TABLE- (or the tablewith fk).
TM 6-TM 6-2020Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Order of Entering Data and Referential Integrity
STUDENTpk fk
SID SLNAME … SPIN FID100 Miller 8891 1… …
105 Connoly 9188 3
FACULTY pk fk
FID FLNAME … LOCID … FPIN1 Cox 53 1181… … …5 Brown 57 9899
LOCATION pkLOCID BLDG_CODE ROOM CAPACITY
45 CR 101 150… …57 LIB 222 1
LOCATION
FACULTY
STUDENT
STUDENTpk fk
SID SLNAME … SPIN FID100 Miller 8891 1… …
105 Connoly 9188 3
FACULTY pk fk
FID FLNAME … LOCID … FPIN1 Cox 53 1181… … …5 Brown 57 9899
LOCATION pkLOCID BLDG_CODE ROOM CAPACITY
45 CR 101 150… …57 LIB 222 1
TABLE-1 TABLE- (FACULTY) (STUDENT)
RULES:
1. You can’t add a record to TABLE- (or the table with fk,e.g., STUDENT) unless there is a corresponding record inTABLE-1 (or the table with pk).
2. You can’t delete a record in TABLE-1 (or the table with pk, e.g., FACULTY) if there is arecord in TABLE- (or the table with fk).
Order of entering data into the database: LOCATION FACULTY STUDENT Order of deleting data from the database:STUDENT FACULTY LOCATION
TM 6-TM 6-2222Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Well-Structured Relations
• A well-structured relation contains minimal redundancy and allows users to insert, modify, and delete the rows in a table without errors or inconsistencies.
• The following anomalies should be removed for a well-structured relation:– Insertion Anomaly– Deletion Anomaly– Modification Anomaly
TM 6-TM 6-2323Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed
100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X100 Margaret Simpson Marketing 48,000 Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X110 Chris Lucero Info. System 43,000 C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X150 Susan Martin Marketing 42,000 Java 8/12/199X
EMPLOYEE2
Is EMPLOYEE2 a Well-Structured relation?
TM 6-TM 6-2424Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Is EMPLOYEE2 a Well-Structured relation?
NO!
WHY?
TM 6-TM 6-2525Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Insertion Anomaly: Inserting a new row, the user must supply values for both Emp_ID (PK) and Course_Title (CK and FK). This is an (insertion) anomaly, since the user should be able to enter employee data without knowing (supplying) course (title) data.
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X100 Margaret Simpson Marketing 48,000 Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X110 Chris Lucero Info. System 43,000 C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X150 Susan Martin Marketing 42,000 Java 8/12/199X
EMPLOYEE2
TM 6-TM 6-2626Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Deletion Anomaly: Deleting the employee number 140, it results in losing not only the employee’s information but also the course had an offering that completed on that date.
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X100 Margaret Simpson Marketing 48,000 Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X110 Chris Lucero Info. System 43,000 C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X150 Susan Martin Marketing 42,000 Java 8/12/199X
EMPLOYEE2
TM 6-TM 6-2727Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Modification Anomaly: If the employee number 100 gets a salary increase, we must record the increase in each of the rows for that employee (two occurences); otherwise the data will be inconsistent.
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X100 Margaret Simpson Marketing 48,000 Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X110 Chris Lucero Info. System 43,000 C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X150 Susan Martin Marketing 42,000 Java 8/12/199X
EMPLOYEE2
TM 6-TM 6-2828Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-7: Normalized Relations from EMPLOYEE2EMPLOYEE2
Emp_ID Name Dept_Name Salary
100 Margaret Simpson Marketing 48,000140 Allen Beet Accounting 52,000110 Chris Lucero Info. System 43,000190 Lorenzo Davis Finance 55,000150 Sususan Martin Marketing 42,000
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed
100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X100 Margaret Simpson Marketing 48,000 Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X110 Chris Lucero Info. System 43,000 C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X150 Susan Martin Marketing 42,000 Java 8/12/199X
Emp_ID Course_ Date_ Title Completed100 SPSS 6/19/199X100 Surveys 10/7/199X 140 Tax Acc 12/8/199X110 SPSS 1/12/199X110 C++ 4/22/199X150 SPSS 6/19/199X150 Java 8/12/199X
EMPLOYEE1 EMP_COURSE
TM 6-TM 6-2929Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Normalization
• Normalization is the process of decomposing relations with anomalies to produce smaller, well-structured and stable relations.
TM 6-TM 6-3030Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Data Normalization
• Normalization is a formal process for deciding which attributes should be grouped together in a relation (see Fig.6-7 next).
• Primarily a tool to validate and improve a logical design so that it satisfies certain constraints that avoid unnecessary duplication of data.
TM 6-TM 6-3131Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-7: Normalized Relations from EMPLOYEE2EMPLOYEE2
Emp_ID Name Dept_Name Salary
100 Margaret Simpson Marketing 48,000140 Allen Beet Accounting 52,000110 Chris Lucero Info. System 43,000190 Lorenzo Davis Finance 55,000150 Sususan Martin Marketing 42,000
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed
100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X100 Margaret Simpson Marketing 48,000 Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X110 Chris Lucero Info. System 43,000 C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X150 Susan Martin Marketing 42,000 Java 8/12/199X
Emp_ID Course_ Date_ Title Completed
100 SPSS 6/19/199X100 Surveys 10/7/199X 140 Tax Acc 12/8/199X110 SPSS 1/12/199X110 C++ 4/22/199X150 SPSS 6/19/199X150 Java 8/12/199X
EMPLOYEE1 EMP_COURSE
TM 6-TM 6-3232Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Functional Dependencies and Keys• Functional Dependency: The value of one
attribute (the determinant) determines the value of another attribute.
• Candidate Key:An attribute, or combination of attributes, that uniquely identifies a row in a relation.
• A candidate key is always a determinant, while a determinant may or may not be a candidate key.
• Each non-key field is functionally dependent on every candidate key.
TM 6-TM 6-3333Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-22:Steps in normalization
TM 6-TM 6-3434Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
First Normal Form
• Normal form is a state of a relation that results from applying simple rules regarding functional dependencies (or relationships between attributes) to that relation.
• No multi-valued attributes.
• Every attribute value is atomic.
• Fig. 6-2a, b.
TM 6-TM 6-3535Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X100 Margaret Simpson Marketing 48,000 Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X110 Chris Lucero Info. System 43,000 C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X150 Susan Martin Marketing 42,000 Java 8/12/199X
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X Java 8/12/199X
TM 6-TM 6-3636Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Second Normal Form
• 1NF and every non-key attribute is fully functionally dependent on the primary key.
• Every non-key attribute must be defined by the entire key (either a single PK or a CK), not by only part of the key.
• No partial functional dependencies.
• Fig. 6-1,6-23a
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Fig. 6-23: A Process of 1NF to 2NF (EMPLOYEE2 - - 1NF)
(b) Functional Dependencies in EMPLOYEE2
Partial Depend.
Emp_ID Course_Title Name Dept_Name Date_CompletedSalary
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed
100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X100 Margaret Simpson Marketing 48,000 Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X110 Chris Lucero Info. System 43,000 C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X150 Susan Martin Marketing 42,000 Java 8/12/199X
TM 6-TM 6-3838Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-23: A Process of 1NF to 2NFEMPLOYEE1
Emp_ID Name SalaryDept_Name
(a) Functional dependencies in EMPLOYEE1 (2NF)
Emp_ID Name Dept_Name Salary
100 Margaret Simpson Marketing 48,000140 Allen Beeton Accounting 52,000110 Chris Lucero Info. System 43,000190 Lorenzo Davis Finance 55,000150 Susan Martin Marketing 42,000
TM 6-TM 6-3939Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Emp_ID Name SalaryDept_Name
Emp_ID Course_Title Name Dept_Name Date_CompletedSalary
Partial Depend.
EMPLOYEE2
EMPLOYEE1
Emp_ID Course_Title Date_Completed
EMP_COURSE
2NF
3NF ?
Fig. 6-23: Summary on Normalization
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EMPLOYEE2 (1NF)
Emp_ID Name Dept_Name Salary
100 Margaret Simpson Marketing 48,000140 Allen Beet Accounting 52,000110 Chris Lucero Info. System 43,000190 Lorenzo Davis Finance 55,000150 Sususan Martin Marketing 42,000
Emp_ID Name Dept_Name Salary Course_ Date_ Title Completed
100 Margaret Simpson Marketing 48,000 SPSS 6/19/199X100 Margaret Simpson Marketing 48,000 Surveys 10/7/199X 140 Allen Beeton Accounting 52,000 Tax Acc 12/8/199X110 Chris Lucero Info. System 43,000 SPSS 1/12/199X110 Chris Lucero Info. System 43,000 C++ 4/22/199X190 Lorenzo Davis Finance 55,000 150 Susan Martin Marketing 42,000 SPSS 6/16/199X150 Susan Martin Marketing 42,000 Java 8/12/199X
Emp_ID Course_ Date_ Title Completed
100 SPSS 6/19/199X100 Surveys 10/7/199X 140 Tax Acc 12/8/199X110 SPSS 1/12/199X110 C++ 4/22/199X150 SPSS 6/19/199X150 Java 8/12/199X
EMPLOYEE1 (3NF) EMP_COURSE (3NF)
Fig. 6-23: Summary on Normalization
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Third Normal Form
• 2NF and no transitive dependencies (functional dependency between non-key attributes.)
• Fig. 6-23, 6-24, 6-25.
TM 6-TM 6-4242Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-24: Relation with transitive dependency
(a) SALES relation with simple data
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What Anomalies might be in SALES relation?
• Insertion anomaly ?• Deletion anomaly ?• Modification anomaly ?
TM 6-TM 6-4444Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-24: (b) Transitive dependency in SALES relation
Cust_ID ---> Name, Salesperson, Region and
Salesperson ---> Region
therefore ...
Cust_ID ---> Region
TM 6-TM 6-4545Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-25: Removing a transitive dependency
(a) Decomposing the SALES relation
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Fig. 6-25: (b) Relations in 3NF
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Snum Origin Destination Distance
409 Seattle Denver 1,537618 Chicago Dallas 1,058723 Boston Atlanta 1,214824 Denver Las Angeles 1,150629 Minneapolis St. Louis 587353 Seattle Denver 1,537
Fig. 6-26: Another example with transitive dependencies
Insertion anomaly?Deletion anomaly?Modification anomaly?
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Break !
TM 6-TM 6-4949Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-26: Another example with transitive dependencies
Snum Origin Destination Distance
SHIPMENT
Snum Origin Destination 409 Seattle Denver 618 Chicago Dallas 723 Boston Atlanta 824 Denver Las Angeles629 Minneapolis St. Louis 353 Seattle Denver
Origin Destination Distance
Seattle Denver 1,537Chicago Dallas 1,058Boston Atlanta 1,214Denver Las Angeles 1,150Minneapolis St. Louis 587Seattle Denver 1,537
TM 6-TM 6-5050Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Fig. 6-22:Steps in normalization
TM 6-TM 6-5151Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Merging Relations(View Integration)
• In a project development process, there may be a number of separate E-R diagrams and user views created and some of them may be redundant.
• Therefore, some relations should be merged to remove the redundancy.
TM 6-TM 6-5252Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Merging Relations(View Integration - A example)
EMPLOYEE1( Employee_ID, Name, Address, Phone)
EMPLOYEE2(Employee_ID, Name, Address, Jobcode,
No_Years)
EMPLOYEE(Employee_ID, Name, Address,Phone, Jobcode, No_Years)
TM 6-TM 6-5353Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Merging Relations(Problems on View Integration)
Synonyms: Different names, same meaning.Homonyms: Same name, different
meanings.Transitive Dependencies: e.g. (Stu ID,
Major) (Stu ID, Advisor).
Supertype/Subtype.
TM 6-TM 6-5454Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Problems on View Integration
Synonyms: Different names, same meaning.STUDENT1(Student_ID, Name)
STUDENT2(Matriculation_No,Name, Address)
STUDENT(SSN, Name, Address)
Homonyms: Same name, different meanings.STUDENT1(Student_ID, Name,Address)
STUDENT2(Student_ID,Name, Phone_No,Address)
STUDENT2(Student_ID,Name, Phone_No, Campus_Address, Permanent_Address)
TM 6-TM 6-5555Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Problems on View Integration
Synonyms: Different names, same meaning.STUDENT1(Student_ID, Name)
STUDENT2(Matriculation_No,Name, Address)
STUDENT(SSN, Name, Address)
Homonyms: Same name, different meanings.STUDENT1(Student_ID, Name,Address)
STUDENT2(Student_ID,Name, Phone_No,Address)
STUDENT2(Student_ID,Name, Phone_No, Campus_Address, Permanent_Address)
TM 6-TM 6-5656Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Problems on View Integration
Transitive DependenciesSTUDENT1(Student_ID, Major)
STUDENT2(Student_ID, Advisor)
the result is ...
STUDENT(Student_ID, Major, Advisor)
and after removing transitive dependencySTUDENT(Student_ID, Major) STUDENT(Major, Advisor)
TM 6-TM 6-5757Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Problems on View Integration
Supertype/SubtypePATIENT1(Patient_ID, Name, Address)
PATIENT2(Patient_ID, Room_No)
PATIENT(Patient_ID, Name, Address)INPATIENT(Patient_ID, Room_No)OUTPATIENT(Patient_ID, Date_Treated)
TM 6-TM 6-5858Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
After learning one of most important database concepts and theories...
WHAT’S NEXT ?
TM 6-TM 6-5959Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Relational Definitions
• Tuple
• Attribute
• View
TM 6-TM 6-6060Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Relational Concepts
• Relational Algebra
• Relational Calculus
• Relational Operations– SELECT– PROJECT– JOIN
• Equijoin - Join field appears twice.
• Natural Join - Join field appears once.
TM 6-TM 6-6161Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database SystemsBusiness Database Systems
Logical Database Design
You have just learned and completed one of the most important concepts and theories, integrity constraints and normalization, for developing a quality of database.