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Define Access Database Column Properties

In a model based on an Access target server, you use the two Access tabs in the Columns dialog to manage the datatype, null option, default value, and other properties for the selected column.

Note: An asterisk next to any property indicates that the property value is derived from domain inheritance or a macro.

To define Access column properties

1. Click Columns on the Model menu.

   The Columns dialog opens.

2. Click both Access tabs, select from the following options in each one, and click OK:

   (First Access tab)

   Access Datatype

   Lets you select a datatype from the list to change the datatype of the selected column. If the selected datatype requires a value for precision, scale, or both, enter the value inside the datatype parentheses. For example, you can select the DECIMAL() datatype and specify a precision of 2 and a scale of 10 inside the parentheses, to assign the datatype DECIMAL(2,10) to the selected column.

   Null Option

   Lets you specify a null option for the selected column.

   Average Width

   Lets you enter an estimated average width for the column if the option is available (not dimmed). You can later use the Volumetrics dialog to calculate table and database size estimates based on these and other values.

   Percent NULL

   Lets you enter the estimated percentage (using whole numbers) of nulls used for that column if the option is available. For example, you can estimate a variable width ADDRESS 2 column assigned a width of 50 characters, to be NULL about 30 percent of the time. You can later use the Volumetrics dialog to calculate table and database size estimates based on these and other values.

   Allow Zero Length

   Specifies to store a zero-length string in this column. Clear this check box to prohibit zero-length strings in this column.

   (Second Access tab)

   Caption

   Lets you enter a name that identifies the column values in Access applications.

   Format

   Lets you specify a display format name to assign a display format to the column. The display format controls how data appears in Access applications. For example, mm/dd/yyyy is a date format that displays a date value as 04/10/2007. Click the button to open the Display Formats dialog.

   Mask

   Lets you enter a symbol string to control how data is entered and displayed in Access applications. For example, by using the input mask (###) ###-####, you can enter just the digits (and only the digits) for a standard North American telephone number. The parentheses, space, and hyphen are entered automatically.

   Access column properties are defined and the Columns dialog closes.