Field properties are settings that define the behavior and characteristics of a field in a database table.

Examples:

• Field Size
• Format
• Default Value
• Required
• Validation Rule
• Validation Text
• Caption
• Indexed

For example, you can make a StudentName field required so that users cannot leave it empty when creating a record.

1. Open your database in Microsoft Access.
2. Right-click the required table in the Navigation Pane.
3. Select Design View.
4. Select the field you want to configure.
5. Look at the Field Properties section below the design grid.
6. Change the required property.
7. Save the table.

Available properties depend on the selected field's data type and your Access version.

Field Size controls the permitted size or range of values for supported data types.

Example:

For a Short Text field, you can set a maximum length appropriate for the information being stored.

• Useful for controlling text length.
• Can help reduce unnecessary storage.
• Can help maintain consistent data entry.

For Number fields, the Field Size setting determines the numeric storage type and range.

The Format property controls how a value is displayed. It generally changes the appearance of a value rather than changing the underlying stored value.

Examples

• Date values can be displayed in different date formats.
• Currency values can display a currency symbol.
• Numbers can be displayed with decimal places.
• Text can be displayed in uppercase or lowercase in supported contexts.

Example:

Default Value automatically supplies an initial value when a new record is created. The user can usually change it unless another rule prevents the change.

Example: Country Field

If most students live in India, you can set the Default Value of a Country field to:

"India"

Other Examples

• IsActive: Yes
• Quantity: 1
• Country: India

The expression must be appropriate for the field's data type. A default value does not automatically update every existing record.

The Required property determines whether a field must contain a value in a record.

Example

Set Required to Yes for StudentName if every student record must have a name.

• Yes: A value must be provided.
• No: The field may be left Null, subject to other rules.

Important: Required does not mean that the field must contain a unique value. Use a primary key or an appropriate unique index when uniqueness is required.

A Validation Rule restricts the values users can enter into a field or record.

Example 1: Marks Between 0 and 100

>=0 And <=100

This rule allows values from 0 through 100.

Example 2: Age 18 or Above

>=18

Example 3: Course Fee Must Not Be Negative

>=0

Validation rules should match the business requirements of your database.

Validation Text displays a message when a value fails the Validation Rule.

Example:

Validation Rule:

>=0 And <=100

Validation Text:

Enter marks between 0 and 100.

If a user enters 120, Access can display the validation message to explain the problem.

Caption provides a more user-friendly label for a field in supported displays, forms, and reports.

Example:

A caption improves readability without requiring you to rename the underlying field.

The Indexed property creates or controls an index on a field. Indexes can improve the speed of searches, sorting, and joins.

Common options include:

• No: No index is created through this property.
• Yes (Duplicates OK): Duplicate values are allowed.
• Yes (No Duplicates): Duplicate values are not allowed.

Examples:

• StudentID: commonly unique.
• Course: duplicates may be allowed.

A primary key automatically has a unique index. Indexes can improve performance, but creating too many can slow down data updates.

Create a Students table with these fields:

Tasks:

1. Open the Students table in Design View.
2. Configure the listed field properties.
3. Save the table.
4. Enter a valid student record.
5. Try entering marks above 100.
6. Observe the validation message.
7. Check whether the Country field receives its default value.

1. What are field properties?
2. Where can you find field properties in Access?
3. What does Field Size control?
4. What is the purpose of the Format property?
5. What does Default Value do?
6. What is the Required property used for?
7. What is a Validation Rule?
8. What is Validation Text?
9. What is the Caption property?
10. What is the purpose of the Indexed property?