Data bases-tools and techniques

Data bases-tools and techniques

1. Table Chartartistics

   • Rows and columns
   • columns=fields
   • Rows=Records
   • Field Types
     • Text(Alphabet)
       • Memo
     • Numeric
       • Numbers
       • Currency
       • Dates
       • Time
     • Bolean
       • True/False
       • Yes/No
     • Web
       • Hyperlink
     • Field size
       • Byte
       • Integar
       • Long Intergar
       • Single
       • Double
       • Decimal

2. Validation

   • To check for errors
   • Applies to a range
   • Correct format
   • Postcode
   • Input 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 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 entered into a field
     • Range check
       • Checks that a value falls within the specified range
     • Spell check
       • Looks up words in a dictionary

3. Recordds

   • Add
     • Manually
     • Externl source
       • Spreadsheet
   • Edit
   • Delete

4. Indexing

   • Primary key
   • Foreign Key

5. Relationships

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