Semifinals - Chapter 3 DBMS

8/14/2019 Semifinals - Chapter 3 DBMS

1/16

Lesson 6

Lesson Objectives Identify dependent and independent fields. Define a normalized database. Create a database/table in MS Access using a

wizard.

Lesson 6: Normalization

Normalization - process with establishedrules and conditions designed to makedatabases more flexible and less prone toupdate anomalies


example of a student information form


Flat file


First Normal Form Second Normal Form Third Normal Form

Three problems normalization solves: Insertion Anomalies Deletion Anomalies Modification Anomalies

Lesson 6: Normalization (1NF)

There are two rules for a table to be in theFirst Normal Form or 1NF:

The intersection of each row and column mustcontain one and only one value (atomicvalues).

Repeating fields and non-repeating fields areseparated into different tables.

Lesson 6: 1NF Lesson 6: Normalization (2NF)

There is just one condition or requirementfor the Second Normal Form or 2NF:

Every attribute within the table must be fullyand functionally dependent on the primarykey.

Lesson 6:2NF

Lesson 6: Normalization (3NF)

There is just one rule that we must followto complete the normalization process upto the Third Normal Form or 3NF:

Transitive dependencies should be eliminated.

Lesson 6: 3NF Lesson 6: Normalization

Lesson 6: Creating a Database Using aWizard

Click on General Templates or On my Computer found on the task pane. If the task pane is not visible,click on the NEW button.



After setting the database type, save yournewly-made database.

Click on the CREATE button when you aredone.


2/16


Lesson 6: Creating a Table Using aWizard

Lesson 6: Creating a Table Using aWizard

Renaming a field

Lesson 6: Creating a Table Usinga Wizard

Lesson 7: Queries

Queries -statements that detail exactlywhat information should be extracted fromthe database.

Select query Crosstab query Parameter query Action query

Lesson 7: Queries

Select Query most common type of query in MS Access and is

used for extracting data fromtable/s based on thespecified criteria.

Action Query enables you to performan action such as delete,

append, and update records that meet thespecified criteria.

Lesson 7: Queries

Parameter Query This type of query allows flexibility in selecting

data by prompting for user input in the selectioncriteria.

Crosstab Query used for summarizing data by grouping data with

correspondingsummary calculations, such as sumor average, based on the specified criteria.

Lesson 7: Creating Queries in DesignView




Lesson 7: Creating Queries in DesignView Lesson 7: Relational

OperatorsOperator

sDescription

> Greater than

>= Greater than orequal to< Less than


3/16

Lesson 7: Relational OperatorsLesson 7: Wildcard Operators

Operator Description Example

*matches characters in any

numberme* f inds meat, meet , andmeeting

? matches any let ter m?ll finds mall andmill

#matches any single-digitnumber

7#2 finds712, 732,772

[]matches any of the characterswithin the brackets

t[io]e f in ds t ie a nd t oe b utnottue

!matches any character not inthe list inside the bracket

t[!io]e f in ds t ue b ut n ot t o eandtie

- matches one character in arange of characters

d[a-d]d f inds dad, dbd, dcd,andddd

Lesson 7: Wildcard Operators

Lesson 7: Logical OperatorsOperator D escription

ANDall specified criteria must bemet

OR eithercriterion must be met

NOT indicated criteria does notneed to be met

BETWEEN Xand Y

the value must be from X toY

IN the value must be in the list

Lesson 7: Logical Operators Lesson 7: Logical Operators

Lesson 7: Creating Queries Usingthe Wizard


See the results?


Lesson 7: Creating Queries Using theWizard Lesson 7: Creating Queries Using the

Wizard

Lesson 7: Creating Queries Using theWizard

Lesson 7: Creating Queries Using theWizard Lesson 7: Creating Queries Using the

Wizard

Lesson 7: Creating Queries Using theWizard


4/16


5/16


6/16


7/16


8/16


9/16


10/16


11/16


12/16


13/16


14/16


15/16


16/16




Semifinals - Chapter 3 DBMS

Documents

Transcript of Semifinals - Chapter 3 DBMS