Databases - Tools and Techniques

Databases - Tools and Techniques

1. Table Characteristics

   • Rows and Columns
     • Columns = Fields
     • Rows = Records
       • Add
         • External Source
           • Spreadsheet
         • Manually
       • Edit
       • Delete
   • Field Types
     • Text
     • Numeric
     • Memo
     • Currency
     • Dates
     • Time
     • Boolean
     • Web
     • Hyperlink
     • Lookup wizards
   • Field size
     • Byte
     • Integer
     • Long integer
     • Single
     • Double
     • Decimal

2. Validation

   • To check for errors
   • Applies to a range
   • Postcode
     • input mask
   • Correct field size
   • Correct data type
   • Examples
     • Check Digit
       • The last one or two digits in the code are used to make sure the rest of the code is correct.
     • Format Check
       • Checks the data in the right format.
     • Length Check
       • Checks the data isn't too short or too long.
     • Lookup Table
       • Looks up acceptable values in a table.
     • Presence Check
       • Checks that data has been dragged into a field
     • Range Check
       • Checks that the value is formed within a specified range.
     • Spell Check
       • Looks up words in a dictionary.

3. Indexing

   • Primary Key
   • Foreign Key

4. Relationships

   • Many to many
   • One to one
   • One to many