Defining columns

You define a condition column by specifying a condition statement. You define an action column by specifying an action statement.

About this task

A decision table must have at least one condition column and one action column. You can define condition and action columns by using the decision table editor.

In a condition column, you enter a condition statement that defines a comparison but not its values.

A condition statement is an incomplete BAL predicate expression whose placeholders are mapped to specific subcolumns. Placeholders are specific tokens enclosed within < and >. They can represent a concept from the vocabulary (for example, <an object>, <a loan>, or <a string>), or empty text defined in the vocabulary phrase, such as is between <min> and <max>.

If you create a condition statement that has more than one placeholder, the required subcolumns are automatically created. If the expression does not contain any placeholders, Rule Designer completes the expression with an ... is a <boolean> statement so that it has a placeholder.

Note: An expression can have placeholders anywhere. However, any ambiguity about the expected definition might trigger a warning.

In an action column, you specify each action to take in each of the specified situations.

Procedure

To define condition and action columns:

  1. Use the decision table editor to define the required columns, as summarized in the following table:
    To define a condition column: To define an action column:
    1. Click the condition column to select it, and click the characters in the top cell of the column. A text field opens.
    2. Enter the name of the column in the field.
    3. With the column still selected, click inside the text box above the table.
    4. Press Ctrl+Space to open the rule completion menu. Construct your condition statement. You can also type your condition statement.
    1. Click the action column to select it, and click the characters in the top cell of the column. A text field opens.
    2. Enter the name of the column in the field.
    3. With the column still selected, click inside the text box above the table.
    4. Press Ctrl+Space to open the rule completion menu. Construct your action statement. You can also type your action statement.
  2. When you have constructed your condition or action statement, click OK.

Results

If you need to redefine a column at any time, double-click the column header and change the required details.

When you have defined at least one condition column and an action column, you can begin to specify values for the placeholders in the condition and action definitions. See Specifying values and operators for details.