You can add create new calculated field based on the existing data source fields. To create a calculated field, right click on the data source area and select Add calculated field, or use corresponding button in the Ribbon's Data Source tab:
This invokes the Expression Editor dialog, which allows you to specify an expression that will be used to obtain calculated field values. Here, you can construct the required expression.
You can use the following elements in expressions.
After the expression has been specified, click OK. This displays a new calculated field in the data source structure. Now you can specify the required calculated field type, change its default name, etc.
To edit a calculated field, use its context menu.
This menu contains the following items.
|Edit Expression...||Invokes the Expression Editor dialog, which allows you to change an expression for an existing calculated field.|
Specifies the type of the calculated field.
|Rename||Changes the calculated field name.|
|Delete||Removes the existing calculated field from the data source.|