Data Types

When creating a table, one will need to specify what kinds of data are to be stored in this field.

The different kinds of Access2003 data are:

Text: allows for the storage of any kind of data, characters, digits and special characters. It has a defect length of 50 characters with a maximum length of 255. It is normally used to store data such as names, addresses, or any number not used in calculations, like telephone numbers or zip codes.

Memo: is used for texts of more than 255 characters such as comments or explanations. It has a maximum length of 65.536 characters. Access recommends that to store formatted text or large documents, rather to create an OLE Object field than a Memo field.

In Access2003 it is possible to arrange or group in a Memo field, but Access only uses the first 255 characters when it arranges or groups in a Memo field.

Number: for numerical data used in mathematical calculations. Within the number type we are able to specify the size property of the field. The types Byte, Integer and Long Integer allow the storage of numbers without decimals; the types Single, Double and Decimal allow decimals; the type Replication ID is used for autonumerical codes in replication databases.

Date/Time: for the introduction of date and time from the year 100 to 9999.

Currency: For monetary values and numerical data used in mathematical calculations in which the data involved contains between one and four decimals. The accuracy is up to 15 digits to the left of the decimal separator and up to 4 digits to the right of the same.

Access recommends the use of Currency type to avoid the rounding off of numbers in calculus. A Currency field has an accuracy of up to 15 digits to the left of the decimal separator and 4 digits to the right. A Currency field occupies 8 bytes of space on disc.

Autonumber: a unique sequential number (increasing one by one), or an aleatory number that Access assigns every time it adds a new record to a table. Autonumber fields can not be updated.

Yes/No: Yes and No values, and fields that contain one of two values (Yes/No, True/False or Acivated/Disactivated).

OLE Object: an object such as a Microsoft Excel spreadsheet, a Microsoft Word document, graphics, images, sounds, or other binaries.

Hyperlink: text or a combination of text and numbers stored as text and used as a hyperlink address. A Hiperlink is a text or grafic that you click to go to a file, a location in a file, a web page on the Internet, or a web page on an intranet.

Another possibility exists which is the Lookup wizard... which creates a field that allows you to choose a value from a list. Access can fill the list with values from a table or with values you type.


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