Creating Temporary Fields

In this section:

How to:

A temporary field is a field whose value is not stored in the data source, but can be calculated from the data that is there, or assigned an absolute value. When you create a temporary field, you determine its value by writing an expression. You can combine fields, constants, and operators in an expression to produce a single value. For example, if your data contains salary and deduction amounts, you can calculate the ratio of deductions to salaries using the following expression: deduction / salary.

You can specify the expression yourself, or you can use one of the many supplied functions that perform specific calculations or manipulations. In addition, you can use expressions and functions as building blocks for more complex expressions, as well as use one temporary field to evaluate another.

There are two types of temporary fields (a virtual field and a calculated value) which differ in how they are evaluated:

You can create temporary fields from the Field selection tab.


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Procedure: How to Create a Temporary Field
  1. On the Field selection tab, click one of the following:
    • New define field icon (located above the fields list)
    • New computed field icon (located with the Sum/Print fields)

    The Field Creator dialog box opens.

  2. Enter the name for the field in the Field box. Field names for temporary fields cannot exceed 66 characters.
  3. Enter the format for the field in the Format box. Click the Format button for assistance in selecting a format. See Change Format Dialog Box.
  4. Click in the expression box to enter an expression.

    If you are familiar with coding Compute and Define expressions, you can type the expression in the text box. Otherwise, you can use the keypad to assist you in creating the expression. To use the keypad:

    1. Click the Tree or List button to open the fields list, or click the Functions button to open the WebFOCUS functions list.

      The functions list displays predefined functions grouped into categories that include Character, Data Source and Decoding, Date and Time, Format Conversion, Numeric, and System. If you hover your cursor over a function, a brief description appears.

    2. Double-click a field or function to add it to the expression box.
    3. If you select one or more fields, complete the expression by typing directly in the expression box or using the Field Creator keypad. See Field Selection Tab: Field Creator Dialog Box for details on keypad operations.

      If you select a function, replace each of the function’s arguments with the desired value or field name. Note that each function is a program that returns a value.

      See the Using Functions manual for complete information on functions.

  5. Click OK. New calculated values (Compute) are added to the column (Sum/Print) list in your report. New virtual (Define) fields are added to the fields list, where you can select them as if they were real fields.

Note: When you create a defined field in Report Assistant, if you want that field value to be blank, the blank must be contained in quotation marks.


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Procedure: How to Edit a Temporary Field
  1. Select the temporary field.
  2. Click the down arrow next to the Define icon and select Edit define field.

    or

    Above the Sum/Print display field list, click the Edit computed field menu item.

    The Field Creator dialog box opens.

  3. Make your desired edits and click OK.

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Procedure: How to Delete a Temporary Field

Select a field in the Sum/Print display field list and click the Delete icon (or press the Delete key).

or

Perform the following steps:

  1. Select a virtual field in the Available fields box.
  2. Click the down arrow next to the Define icon.
  3. Click Delete define field.

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Examples of Creating a Virtual Field and Creating a Calculated Value

The following are examples of creating a virtual field and creating a calculated value.



Example: Creating a Virtual (Defined) Field Using a Function

The following image shows the Define Field Creator dialog box with a defined field that uses a function (ARGLEN). This field uses the EMPLOYEE sample data source.



Example: Creating a Calculated (Computed) Value

The following image shows a computed field created using the SALES sample data source. The expression creates the computed field REVENUE based on the product of the existing fields UNIT_SOLD and RETAIL_PRICE.


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Changing a Field Format

How to:

The following image shows the Change Format Dialog box, which you use to assign a format to a virtual or column field. Refer to the following procedures for the step-by-step instructions.



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Procedure: How to Assign an Alphanumeric Format
  1. Select the virtual or column field.
  2. Click the down arrow next to the Define icon and select Edit define field.

    or

    Click the New computed field icon.

    The Field Creator dialog box opens.

  3. Click Format. The Change Format dialog box opens.
  4. Select the Alphanumeric option button in the Format Types option button group.
  5. To assign a different length, specify a number between 1 and 256 in the Length spin box.
  6. Click OK twice to close the Change Format dialog box and return to the Field selection window. The new format appears in the Format column in the Available fields list.


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Procedure: How to Assign a Numeric Format
  1. Select the virtual or column field.
  2. Click the down arrow next to the Define icon and select Edit define field.

    or

    Click the New computed field icon.

    The Field Creator dialog box opens.

  3. Click Format. The Change Format dialog box opens.
  4. Select one of the following option buttons in the Format Types option button group:
    • Floating Point (default length 7.2)
    • Integer (default length 5)
    • Decimal (default length 12.2)
    • Packed (default length 12.2)

    If the selected field matches the selected format type, its current length appears in the Length spin box. Otherwise, the default length appears in the Length spin box. The Decimal spin box shows the number of decimal places for Floating Point, Decimal, and Packed.

  5. To assign a different length, specify numbers in the Length spin box for format types as follows: 1- 9 for Floating Point, 1- 11 for Integer, 1- 20 for Decimal, and 1- 33 for Packed.
  6. To assign a different number of decimal places for Floating Point, Decimal, or Packed, specify the number in the Decimal spin box.
  7. Click OK twice to close the Change Format dialog box and return to the Field selection window. The new format appears in the Format column in the Available fields list.


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Procedure: How to Assign a Date Format
  1. Select the virtual or column field.
  2. Click the down arrow next to the Define icon and select Edit define field.

    or

    Click the New computed field icon.

    The Field Creator dialog box opens.

  3. Click Format. The Change Format dialog box opens.
  4. Select the Date option button in the Format Types option button group. The default date display format is MDY.
  5. To assign a different date display format, click the down arrow to the right of the Date Format list box.
  6. Choose a date format.
  7. Click OK twice to close the Change Format dialog box and return to the Field selection window. The new format appears in the Format column in the Available fields list.


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Procedure: How to Add a Percent Sign to a Numeric Field

You can add a percent sign to the end of a numeric value (Decimal, Integer, Floating Point format types). This numeric display option includes a percent sign along with the numeric data, but does not calculate the percent.

  1. Select the virtual or column field.
  2. Click the down arrow next to the Define icon and select Edit define field.

    or

    Click the New computed field icon.

    The Field Creator dialog box opens.

  3. Click Format. The Change Format dialog box opens.
  4. Click the down arrow in the Select options list box to choose Percent sign - %.
  5. Click OK twice to close the Change Format dialog box and return to the Field selection window. The new format appears in the Format column in the Available fields list.


Example: Using the Percent Sign Edit Option

The following table consists of a Format column for each numeric format, a Data column for its actual data value, and a Display column for how it appears.

Format

Data

Display

I2%

21

21%

D7%

97

97%

F3.2%

48

48.00%



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Using Calculated Values From the Master File

Reference:

In the Report and Graph Assistants, calculated values (COMPUTEs) that exist in the Master File appear in the fields list with all other temporary virtual fields and calculated values. The following image shows the fields list in the Report Assistant with a calculated value from the Master File (PROFIT).

Calculated values from the Master File are available in all fields lists in the Report Assistant except for the fields lists that appear for Define fields and Joins.



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Reference: Support for Calculated Values From the Master File

You can use a calculated value from the Master File:

Calculated fields from the Master File are not supported:



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Reference: Calculated Value Dependencies

These dependencies apply to calculated values from the Master File and to temporary calculated values.

When you include a calculated value in selection criteria or in a page heading/footing, the field must exist in the report as either a By sort field or a Sum/Print field. If you create a selection criteria statement with a calculated value or add a calculated value to a page heading/footing and the field does not already exist in the report, then it is automatically added to the Sum/Print display field list. The Make this field invisible option is automatically selected in the Field options dialog box so that the calculated value does not appear in the output. When this occurs, a message appears stating:

The field has been added to the list of fields in the report.

Note: You do not see this message for temporary calculated values (those that do not come from the Master File) that are added to a page heading/footing since these already appear in the Report headings fields list.

You can change the attributes of the calculated value from the Field options dialog box on the Field selection tab. If you attempt to delete the calculated value from the Sum/Print display list and the same field exists in either selection criteria or in a page heading/footing, you receive a one of the following messages:

or

You must remove the field from the page heading/footing or selection criteria before you can remove it from the Sum/Print display list.


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