What is Data Type? & What are Different Data Types?

  • A data type is a characteristic of a field that determines the kind of data that can be stored in the field. It is an attribute for a field that specifies the type of data it can store. Each field can store data relating of only a single data type.
  • The different data types supported by Ms-Access are:
Data Type Storage Size
1. Text 0 - 255 characters (Short, alphanumeric values)
2. Number 1, 2, 4, 8 bytes
  • Byte = 0 to 255 (1 byte)
  • Interger = -32768 to 32767 (2 bytes)
  • Long interger = -2 billion to 2 billion (4 bytes)
  • Single precision: = -3.402823E38 to 3.402823E38 (4 bytes)
  • Double = 10 digits (8 bytes)
3. Memo 0 - 65,535 characters
4. Date/Time 8 bytes
5. Currency 8 bytes
6. Auto Number 4 bytes
7. Yes/No 1 bit (0 or 1) (Yes/No, True/False, On/Off)
8. OLE Object Upto 1 GB
9. Hyperlink Upto 2048 characters
10. Lookup Wizard 4 bytes
  1. Text : The text field data type is the default data type. It stores alphanumeric characters.
  2. Number: It stores numeric data on which mathematical calculations have to be performed. This data type allows only numbers to be entered.
  3. Memo: It is similar to the text data type except its length. Generally the descriptions, remarks or notes etc are given to this data-type.
  4. Date/Time: This data type stores date and time.
  5. Currency: This data type allows to store monetary values such as cost. (like Rs., $, etc). Currency data type can be used in mathematical calculations.
  6. Auto Number: This data type generates the serial number automatically in the field. It is the data type of field that does not allow to enter data in the field. A value of auto-number can not be updated. By default auto number starts with one and has increment of one. The auto-number field data type is also known as counter. 
  7. Yes/No: The Yes/No data type allows just to select Yes or No when completing the field. This data type can store logical value that can be only one of two possible values such as Yes/No, True/False, or On/Off. This type type is also known as Boolean data type.
  8. OLE Object: This allows to link to binary data or files. It allows to store pictures, charts, audio and video. It also allows to embed an object such as Microsoft Excel spreadsheet, a Microsoft word document, Microsoft Powerpoint presentation etc in a table.
  9. Hyperlink: It allows to create hyperlink. This data type allows to store web site address, email address, database object or other files linked. 
  10. Lookup Wizard: It creates either a list box or combo box that allows to select information from another table or information assigned. This creates a field that allows to choose a value from another table or from a list of values by using a list box or combo box. When this data type is selected, a wizard helps to create the list. After completing the wizard, MS-Access sets the data type type based on the values selected in the wizard.

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