Spreadsheet vs Database by liamei12345

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									   Spreadsheet vs Database
• When do we use them?
       Spreadsheet review
• Why do we use a spreadsheet?
        Spreadsheet review
• Enter data
• Do calculations on data

• Examples: expenses, profit/loss
Expenses
Gradesheet
               Database
• Store information long-term
• Search information
             An example…
• What sort of information does Ren Da Fu
  Zhong need to keep?

• Think of at least 10 pieces of information!
 RDFZ stores information on…
• Students:
  – Name, address, ID number, parents, grades,
    classes, teachers, payment info, absences,
    extra activities
• Teachers:
  – Name, address, ID number, classes taught,
    students taught, grades given, bank
    information, payment information
 RDFZ stores information on…
• Other employees:
  – Name, job, hours worked/week, pay scale,
    bank information, duties/responsibilities
• Inventories:
  – How many classrooms, how many desks,
    chairs, overhead projectors, scanners,
    computers…
 RDFZ stores information on…
• Lots of stuff!

• Can all of this fit on one spreadsheet?
  – No!
  – This is when we use a database.
           Uses of a database
•   Store data
•   Backup data
•   Add/Modify data
•   Query data (ask questions)
•   Generate reports (print data in an easy-to-
    read format)
     Examples of databases
• Can you think of any?
Your music
Your games
Your web pages
Your life
               Warning!
• Databases are very different from word
  processors, spreadsheets, or presentation
  software.
• You CANNOT just start typing.
• A database must be DESIGNED before
  you start adding data.
• Why?
                  Why?
• Avoid duplication (putting in the same data
  many times)
• Logical organization of data
     The parts of a database
• Do you remember:
  – Columns?
  – Rows?
  – Cells?
• These have different names in a
  database… 
Table: one page
Column = Field
       • We have 3 fields: ID,
         title, and date
       • Notice – every field
         has the same data
         type!
       • This is required!
Data Type review
        • Remember these
          from Excel?
              Row = Record



• Here we have 4 records
• Each record has all the information from one
  entry.
            Another example



• Here we have 3 records
• A record has all the info on one entry
            Cell: Data Value




• How many data values are in this table?
                Primary Key




• Here, the “Video Collection” field is the primary
  key
• EVERY table MUST have a primary key – a
  unique value
Primary Key Examples
      Designing a Database
• Before we enter data, we must design the
  table
• Things to think about:
  – What fields do we need?
  – What data type does each field need?
  – Which field can become the primary key?
           Example: RDFZ
• What information will RDFZ store about
  students?
• What data type should each be?
• Which field will make a good primary key?
   Example: Taobao business
• We are running a business on TaoBao.
  We are selling clothing on the internet.
  We want to make a database of all the
  orders that we receive.

• What information must we store?
• What data type should each field be?
• What should be the primary key?
       Example: a new home
• We are real estate agents, and need to
  build a database of all apartments in the
  area.

• What information must we store?
• What data type should each field be?
• What should be the primary key?

								
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