Calculated Column Usage Examples
Here are some examples of the Calculated Column element in use.
1. The following shows a simple implementation - calculating sales tax:
![](https://devnet.logianalytics.com/hc/article_attachments/7522855778071/calccol_01.png)
In the definition shown above, a Data Table and a datalayer element have been added. A Calculated Column element has been added beneath the datalayer and its attributes have been configured so that it will multiply the values in the ProductSales column by a constant to produce the sales tax amount.
![](https://devnet.logianalytics.com/hc/article_attachments/7522880630295/calccol_02.png)
The resulting sales tax amount will be placed in a new column, named calcTax, in every row of the datalayer, as shown above. The data will be accessible as the token @Data.calcTax~. Instead of hard-coding the sales tax rate in the formula, it could be made dynamic using a token, like this:
- @Data.ProductSales~ * @Request.TaxRate~
Here's a slightly different example: the following expression uses the intrinsic IIF function to apply different tax rates, depending on other criteria:
- IIF(@Data.CategoryID~ = 4, @Data.ProductSales~ * @Request.TaxRate1~, @Data.ProductSales~ * @Request.TaxRate2~)
Of course, your expression doesn't have to use data from the datalayer at all. The following example simply creates a new column and puts the elapsed seconds for every row for it:
- DateDiff("s", CXMLDate("@Request.StartTime~"), CXMLDate("@Function.Time~"))
Note the use of the intrinsic CXMLDate function, which is necessary to convert ISO formatted XML DateTime data into a format that works with the DateDiff function (and should be used with DateAdd, DatePart, and other date functions).
The possibilities are endless and allow developers a great deal of flexibility in manipulating the datalayer.
2. This example illustrates how the value created by one Calculated Column can be used in another Calculated Column.
![](https://devnet.logianalytics.com/hc/article_attachments/7522863937943/calccol_03.png)
In the definition shown above, a second Calculated Column has been added beneath the datalayer. As you can see, its Formula attribute uses data from one of the retrieved data columns and the first calculated column.
![](https://devnet.logianalytics.com/hc/article_attachments/7522849751063/calccol_04.png)
The resulting total amount will be placed in a new column, named calcTotal, in every row of the datalayer, as shown above. The data will be accessible as the token @Data.calcTotal~.