BACKGROUND
•Terms - data,information, file record, table, row , column, transaction,
concurrency
•Concepts - data integrity, data redundancy,
•Type of databases – single-user, shared, etc.
•Meta data versus actual operational data
•Functions of a DBMS
1.Data Dictionary Management
2.Data Storage Management
3.Data presentation ( access through SQL)
4.Security
5.Multi-User (transaction)
6.Back-up and Recovery (stores multiple versions)
•Data Models
1.Attributes
2.Relationships (1-1, 1-many)
3.Constraints
•Using Access
1.Different views – Dataview, Datasheet
2.Declaring column datatypes
3.Primary keys
4.Relationship diagrams
5.Cascade deleting
NORMALILZATION
•Definition – Remove redundancies by segmenting and eliminating
dependencies
•Normal Forms
•1st Normal – No repeating fields
•2nd Normal – No partial dependencies
•3rd Normal – No transitive dependencies
SQL SELECT STATEMENTS
•Column Select
•- rename column with AS
•- * means all columns
•- [ ] for column name with embedded spaces
•Use of aggregate functions
•FROM
•Join tables, rename tables
•WHERE
•RELATIONAL ALGEBRA comparisons
•Can implement logical join
•GROUP BY
•Creates Summary Record
•Having is similar to where clause
•ORDER BY (sort criteria)
• ASC or DESC
Steps in normalization
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Table with multivalued attributes, not in 1st normal form
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Table with no multivalued attributes and unique rows, in 1st
normal form
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Functional dependency diagram for INVOICE
Order_ID  Order_Date, Customer_ID, Customer_Name, Customer_Address
Customer_ID  Customer_Name, Customer_Address
Product_ID  Product_Description, Product_Finish, Unit_Price
Order_ID, Product_ID  Order_Quantity
Therefore, NOT in 2nd Normal Form
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Figure 5-28 Removing partial dependencies
Getting it into
Second Normal
Form
Partial dependencies are removed, but there
are still transitive dependencies
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Third Normal Form



2NF PLUS no transitive dependencies
(functional dependencies on non-primary-key
attributes)
Note: This is called transitive, because the
primary key is a determinant for another
attribute, which in turn is a determinant for a
third
Solution: Non-key determinant with transitive
dependencies go into a new table; non-key
determinant becomes primary key in the new
table and stays as foreign key in the old table
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