Part I: Access Building Blocks
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l (^) Validation Rule: Ensures that data entered into the field conforms to some business rule,
such as “greater than zero,” “date must occur after January 1, 2000,” and so on.
l (^) Validation Text: Displays a message when data fails validation.
l Required: Specifies whether you must enter a value into a field.
l (^) Allow Zero Length: Determines whether you may enter an empty string (““) into a text
field to distinguish it from a null value.
l (^) Indexed: Speeds up data access and (if desired) limits data to unique values. Indexing is
explained in greater detail later in this chapter.
l (^) Unicode Compression: Used for multi-language applications. Requires about twice the
data storage, but enables Office documents, including Access reports, to be displayed cor-
rectly no matter what language or symbols are used. Generally speaking, Unicode is of no
value unless the application is likely to be used in Asian environments.
l (^) IME Mode: Also known as the Kanji conversion mode property, this is used to show
whether the Kanji mode is maintained when the control is lost. The setting has no rele-
vance in English or European-language applications.
l IME Sentence Mode: Used to determine the Sequence mode of fields of a table or con-
trols of a form that switch when the focus moves in or out of the field. The setting has no
relevance in English or European-language applications.
l (^) Smart Tags: Used to assign a specific action to obtain data in this field. For example, the
Financial Symbol Smart Tag obtains recent stock quotes from MSN Money Central.
Format
The Format property specifies how the data contained in table fields appears whenever the data is
displayed or printed. When set at the table level, the format is in effect throughout the application.
There are different format specifiers for each data type.
Access provides built-in format specifiers for most field data types. The exact format used to dis-
play field values is influenced by the Regional Settings in the Windows Control Panel.
The Format property affects only the way a value is displayed and not the value itself or how the
value is stored in the database.
If you elect to build a custom format, construct a string in the field’s Format property box. There
are a number of different symbols you use for each data type. Access provides global format speci-
fications to use in any custom format specifier:
l (^) (space): Display spaces as characters.
l “SomeText”: Display the text between the quotes as literal text.
l (^)! (exclamation point): Left-aligns the display.
l * (asterisk): Fills empty space with the next character.
l (^) \ (backslash): Displays the next character as literal text. Use the backslash to display
characters that otherwise have special meaning to Access.