Databases - tools and techniques

Databases - tools and techniques

1. Table characteristics

   • Rows and columns
   • Columns = fields
     • Field types
       • Alphabetic
         • Text
         • Memo
       • Numeric
         • Numbers
         • Currency
         • Date
         • Time
       • Boolean/logical
         • Yes/No
         • True/False
       • Web
         • Hyperlink
       • Lookup wizards
   • Rows = records
   • Field size
     • Byte
     • Integer
     • Long integer
     • Single
     • Double
     • Decimal
   • Field formats
     • Fixed
     • Decimal places
   • Default values

2. Validation

   • To check for errors
   • Applies to a range
   • Correct format
     • Postcode
       • Input mask
   • Correct field size
   • Correct data types
   • Examples
     • Check digit
       • The last one or two digits in the code are used to see if the other numbers are correct.
     • Format check
       • Check to see if the date is in the right format
     • Length check
       • Makes sure the size of data is right
     • Lookup table
       • Makes sure the values in table is acceptable
     • Presence check
       • Checks that all fields that need data has data
     • Range check
       • Makes sure all values are in the specified range
     • Spell check
       • Checks that all words are spelt right

3. Records

   • Add
     • Manually
     • External source
       • Spreadsheet
   • Edit
   • Detele

4. Indexing

   • Primary key
   • Foreign key

5. Relationships

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