Create a computed column

A computed column is one of the most useful analytical tools in 1010data. Use a computed column to add a column of information to a worksheet typically using the information from one or more existing columns.

1. Open the Sales Item Detail table (pub.demo.retail.item) by completing the following:
   1. In the Folders and Tables browser, enter pub.demo.retail.item in the toolbar search field.
      
   2. Click the Go () icon.
   1010data displays the Sales Item Detail table.

   

   In this tutorial, the Sales and Cost columns, outlined above, are used to create the Margin computed column.

2. Click Columns > Create Computed Column.
   
   1010data displays the Create Computed Column dialog.

   

3. Complete the following fields in the Create Computed Column dialog:

   Column Name	Enter margin. This is the name 1010data uses to interact with the column. It is also used when writing more advanced value expressions and queries. The column name may only contain alphanumeric characters or underscores and must begin with an alphabetic character (e.g., percent_total_sales). It may not contain any spaces or other special characters. This is a required field.
   Column Heading	Enter Margin. This is the label of the column that displays by default at the top of a column in the user interface. The column heading may contain any combination of uppercase and lowercase letters, numbers, spaces, and special characters. If you want to have a multi-line column heading, use the backtick character (`) to separate the lines (e.g., "Percentage of`Total Sales (%)"). While not required, this field is recommended.
   Value Expression	Enter sales-cost. In 1010data, a value expression is a calculation you create to help you analyze your data. In this case, the value in the cost column is subtracted from the value in the sales column. You can write a value expression that performs either simple or advanced calculations. This is a required field.
   Display Format	Select Number: 1,234,567.89. This drop-down list instructs 1010data how to display the new number in the computed column. For example, as a date, a number, as text, and so forth. This field is not required and can usually be left as the default value.
   Column Width	Select 5. This drop-down list determines how many place values to hold in the column. In other words, the width of the column by the number of characters. This field is not required and can usually be left as the default value.
   Decimal Places	Select 2. This drop-down list sets how many numbers are displayed after the decimal point. In this tutorial, dollar amounts are used. Therefore, two decimal places are usually the appropriate setting. However, as you explore 1010data and computed columns, you may find that there are situations where you need more or none at all. This field is not required and can usually be left as the default value.

   You might be asking yourself, "What is actually happening here?" To put it simply, what you just entered above indicates you are creating a new computed column named margin. The margin column is the value of the sales column minus the value of the cost column.

   

   You might have noticed the small table at the bottom of the Create Computed Column dialog. This table is helpful in finding the name for the columns in this table. It is important to remember when writing a value expressions to always use the column name, not the column heading.

4. Click Submit.
   1010data creates the Margin computed column.

   

5. When you are finished with this tutorial, close the Sales Item Detail worksheet.