Column Validation

Use the Column Validation dialog to define data validation rules for the currently selected column.

Validation Type

The dialog supports four different ways to define validation rules. These are referred to as the Validation Types: Simple, Range, Boolean and Validation Object.

First, select one of the four Validation Types from the Validation Type radio group. You can also select "None", to remove any validation rules for the column.


Simple validation is used when the list of column values is limited to a static, small set of simple values. The validation is specified in a "check" string. This consists of a list of valid values separated by the | symbol. For example, the choices A, B and C would be represented by the check string "A|B|C". The choices CA, FL, and TX would be represented by the check string "CA|FL|TX".

Note: the length of each item listed must be the same as the length of the column and padded with spaces as needed. For example, if a column is 6 characters wide, all values listed must be padded with spaces to fill the entire 6 characters. For example: "Red   |Orange"


Range validation is used to define a minimum and maximum range for the column values. It is expected that the column data type will be Numeric or Date. The "From" value must be lower than the "To" value.

Boolean (checkbox)

Boolean validation sets the column up for use in a checkbox control. A checkbox column can only store one of two values: a value to represent the True (checked) state and a value to represent the False (unchecked) state.

Validation Object

Validation Objects are used to constrain the column values via a special class of objects. These objects maintain lists of valid column values. The list may be either statically defined in the object declaration or it may be read in from a special database Table (CodeMast).

Enter the name of the validation object you wish to reference for the current column, or select an existing validation object name from the combo-list. Only validation objects that are declared in the same data dictionary component (file) are listed in the combo.

Validation Objects should be used in preference to the other validation types when:

Validation Objects are separate from the Data Dictionary class declaration and can be referenced by multiple columns in a data dictionary. Data Dictionary Modeler models validation object declarations in the Validation Objects tab.

Validation Error

Enter an error number and error message string. This will be the error message that is displayed to the user when the user tries to enter data into this column that does not match the column's validation rule. If you do not specify a custom validation error then a generic validation error message will be shown instead.

For more information see Field_Error.


See Also

Field Validations

Data Dictionary Column Properties

Data Dictionary Validation Objects