Note The information in this topic applies only to a Microsoft Access database (.mdb).
The following list summarizes all the field data types (field data type: A characteristic of a field that determines what kind of data it can store. For example, a field whose data type is Text can store data consisting of either text or numeric characters, but a Number field can store only numerical data.) available in Microsoft Access, their uses, and their storage sizes.
Use for text or combinations of text and numbers, such as addresses, or for numbers that do not require calculations, such as phone numbers, part numbers, or postal codes.
Stores up to 255 characters. The FieldSize property controls the maximum number of characters that can be entered.
Use for lengthy text and numbers, such as notes or descriptions.
Stores up to 63,999 characters.
Use for data to be included in mathematical calculations, except calculations involving money (use Currency type).
Stores 1, 2, 4, or 8 bytes; stores 16 bytes for Replication ID (GUID). The FieldSize property defines the specific Number type.
Use for dates and times.
Stores 8 bytes.
Use for currency values and to prevent rounding off during calculations.
Stores 8 bytes.
Use for unique sequential (incrementing by 1) or random numbers that are automatically inserted when a record is added.
Stores 4 bytes; stores 16 bytes for Replication ID (GUID).
Use for data that can be only one of two possible values, such as Yes/No, True/False, On/Off. Null (Null: A value you can enter in a field or use in expressions or queries to indicate missing or unknown data. In Visual Basic, the Null keyword indicates a Null value. Some fields, such as primary key fields, can't contain a Null value.) values are not allowed.
Stores 1 bit.
Use for OLE objects (such as Microsoft Word documents, Microsoft Excel spreadsheets, pictures, sounds, or other binary data) that were created in other programs using the OLE (OLE: A program-integration technology that you can use to share information between programs. All Office programs support OLE, so you can share information through linked and embedded objects.) protocol.
Stores up to 1 gigabyte (limited by disk space).
Use for hyperlinks (hyperlink: Colored and underlined text or a graphic that you click to go to a file, a location in a file, a Web page on the World Wide Web, or a Web page on an intranet. Hyperlinks can also go to newsgroups and to Gopher, Telnet, and FTP sites.). A hyperlink can be a UNC path (universal naming convention (UNC): A naming convention for files that provides a machine-independent means of locating the file. Rather than specifying a drive letter and path, a UNC name uses the syntax \\server\share\path\filename.) or a URL (Uniform Resource Locator (URL): An address that specifies a protocol (such as HTTP or FTP) and a location of an object, document, World Wide Web page, or other destination on the Internet or an intranet, for example: http://www.microsoft.com/.).
Stores up to 2048 characters.
Use to create a field that allows you to choose a value from another table or from a list of values using a combo box—-choosing this option in the data type list starts a wizard to define this for you.
Requires the same storage size as the primary key (primary key: One or more fields (columns) whose values uniquely identify each record in a table. A primary key cannot allow Null values and must always have a unique index. A primary key is used to relate a table to foreign keys in other tables.) that corresponds to the Lookup field (Lookup field: A field, used on a form or report in an Access database, that either displays a list of values retrieved from a table or query, or stores a static set of values.)—-typically 4 bytes.