The following table describes the different types of data that can be stored in a database.
Monday, February 27, 2012
Sunday, February 26, 2012
QR Codes
QRCODES (quick response codes) are a type of matrix barcode.
This diagrem shows all of the different components of a QR code
What types of data can they hold?
Where are they used?
They were initially used to track parts in vehicle manufacturing. They are now used much more widely in commercial tracking, entertainment and loyalty marketing to name a few. QR codes can be found on many advertisements so that when you scan one... you are taken to a pictre, link or video that will give you more information about that product.
How do you use them? -> software... hardware.
Different standards?
http://en.wikipedia.org/wiki/QR_code
Tuesday, February 14, 2012
Creating A Baisic Database
Tables, the building blocks of databases
Tables store data, so they are essential for any database
Every major subject should be kept in a different table to avoid confusion
Each table contains rows called records and columns called fields.
Fields Of Data
Fields are renameable
The data type of a field limits the type of information that you can enter. for example, number or currency
A unique identifier can be used for each record in the table
Additional control over the data are provided by the field properties that are a set of charatieristics
Each Record Is Unique
No two records are the same
The primary key is an identifier that is unique to each record and it should not change frequently
It's All Relative
The ID appears in all tables as a primary key and as a foreign key
A primary key separates similar information and makes each record unique. It also brings information together.
Primary keys link tables together
This is how we avoid repeated information on more than one table
When tables relate, the primary key of one table becomes a foreign key of the other table.
Practice
Test Yourself
Queries
queries can answer your questions by assembling stored data from a database
queries retrieve, sort, filter and assemble data on command
queries can combine wanted data from multiple tables
a querie can perform calculations
a querie can also remove data
Forms
graphic elements are stored in the form's design
forms make the data be viewed easily
http://office.microsoft.com/en-us/training/get-to-know-access-RZ006118141.aspx?section=17
Tables store data, so they are essential for any database
Every major subject should be kept in a different table to avoid confusion
Each table contains rows called records and columns called fields.
Fields Of Data
Fields are renameable
The data type of a field limits the type of information that you can enter. for example, number or currency
A unique identifier can be used for each record in the table
Additional control over the data are provided by the field properties that are a set of charatieristics
Each Record Is Unique
No two records are the same
The primary key is an identifier that is unique to each record and it should not change frequently
It's All Relative
The ID appears in all tables as a primary key and as a foreign key
A primary key separates similar information and makes each record unique. It also brings information together.
Primary keys link tables together
This is how we avoid repeated information on more than one table
When tables relate, the primary key of one table becomes a foreign key of the other table.
Practice
Test Yourself
queries can answer your questions by assembling stored data from a database
queries retrieve, sort, filter and assemble data on command
queries can combine wanted data from multiple tables
a querie can perform calculations
a querie can also remove data
Forms
graphic elements are stored in the form's design
forms make the data be viewed easily
http://office.microsoft.com/en-us/training/get-to-know-access-RZ006118141.aspx?section=17
Monday, February 13, 2012
class questions
Suppliers Table
contact name
contact number of companies in the USA
contact name
contact number of companies in the USA
Product table
product names that cost more than $20
Products with more than 30 items in stock
Sunday, February 5, 2012
datatbase definitions
each row is called a record
each column is called a field
fields make up records
records make up the database file
altogether it is called a database
query - search for records that match field criteria
Report - The database's response to a query eg. Sally's address.
DMBS - Database Management System
Data Dictionary - Information that describes the contents, format and structure of the database and the relationship between its elements that are used to control access to and manipulation of the database.
each column is called a field
fields make up records
records make up the database file
altogether it is called a database
query - search for records that match field criteria
Report - The database's response to a query eg. Sally's address.
DMBS - Database Management System
Data Dictionary - Information that describes the contents, format and structure of the database and the relationship between its elements that are used to control access to and manipulation of the database.
data types
- alphanumeric text - abc...123... ?*/....
- Numeric - numbers only - 0 to 9
- Objects - photos, audio files (any digital object)
- Boolean - only two options
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