databases-tools and techniques

databases-tools and techniques

1. table characteristics

   • row and columns
   • columns = fields
   • row= records
   • files types
     • alphabetical
       • text
       • memo
     • numeric
       • numbers
       • currency
       • dates
       • time
     • Boolean/logical
       • yes/no
       • true/ false
     • web
       • hyperlinks
     • filed size
       • byte
       • integer
       • long integer

2. validation

   • to check for errors
   • applies to a range
   • correct format
     • postcode
       • imput mask
   • correct field size
   • correct data type
   • examples
     • check digit
       • the last one or two digits in a code are used to check the other digits are correct
     • format check
       • checks the data is in the right place
     • length check
       • checks if the data is not too short / long
     • lookup table
       • look for acceptable value in a table
     • presence check
       • checks that data has been entered into a place( field)
     • range check
       • checks that a value falls within the specified range
     • spell check
       • looks up words in a dictionary

3. Records

   • add
     • manually
     • external source
       • spreadsheet
   • edit
   • delete

4. indexing

   • primary key
   • secondary

5. relationship

   • one to one
   • many to many
   • one to many