database

• database

  collection of data that is stored in logical and ordered manner
• Why are databases useful?

  • the same data can be viewed and used by everyone who has access
  • they can store a lot of information
  • prevents data problems since data is only written once and there is no duplications
• field is an individual piece of data being stored about an object
• Record is a collection of these fields about one object
• Entities is each recorded item
• Attributes are details about the entity
• Table is a set of fields and records
• Design view shows how the information is viewed with datatypes
• Data view shows how the information is stored in a table
• alphanumeric


  Any combination of letters, symbols & numbers
• character

  A single letter, number or symbol
• integer

  A whole number
• real

  A number with atleast one decimal
• Primary key is a column in a table that uniquely identifies each row in a table
• Verification checks that the data is actually the data you want
• validation rule box is used to specify the requirements for data entered in the field
• validation text box is a message that will be displayed to the user when data that breaks the validation rule is entered
• Data validation  provides a message to help users who input data which was checked by the database that it breaks the validation rule
• SQL stands for structured query language.
• SQL script is a set of statements that are executed