Primary Key

Primary Key

• One or more fields (columns) whose value or values uniquely identify each record in a table. A primary key does not allow Null values and must always have a unique value. A primary key is used to relate a table to foreign keys in other tables.
• NOTE: You do not have to define a primary key, but it's usually a good idea. If you don't define a primary key, Microsoft Access asks you if you would like to create one when you save the table.
• For our tutorial, make the Soc Sec # field the primary key, meaning that every student has a social security number and no 2 are the same.
  • To do this, simply select the Soc Sec # field and select the primary key button
    
  • After you do this, Save the table

Switching Views

• To switch views form the datasheet (spreadsheet view) and the design view, simply click the button in the top-left hand corner of the Access program.

Datasheet View	Design View
Displays the view, which allows you to enter raw data into your database table.	Displays the view, which allows you to enter fields, data-types, and descriptions into your database table.

Entering Data

• Click on the Datasheet View and simply start "chugging" away by entering the data into each field. NOTE: Before starting a new record, the Soc Sec # field must have something in it, because it is the Primary Key. If you did not set a Primary Key then it is OK.

 Manipulating Data

• Adding a new row
  • Simply drop down to a new line and enter the information
• Updating a record
  • Simply select the record and field you want to update, and change its data with what you want
• Deleting a record
  • Simply select the entire row and hit the Delete Key on the keyboard