如何在Microsoft Access数据表中用表达式生成器计算用户输入值的20%？

Hey there! No worries about your initial broad question—let’s walk through exactly how to do this, since it’s a common task across most data tools with expression builders. The core idea is simple: multiply your existing total amount column by 0.2 (or 20%) to get the desired value. Here’s a step-by-step breakdown for some of the most popular tools:

General Core Logic #

The formula you’ll use is always some variation of:

[Your Total Amount Column] * 0.2

(Or [Your Total Amount Column] * 20%—most tools accept either format.)

Step-by-Step for Common Tools #

Excel (Power Query Editor) #

• Open your Excel file and go to the Data tab, then click From Table/Range to launch Power Query.
• In the Power Query Editor, select the Add Column tab.
• Click Custom Column to open the expression builder.
• In the formula box, paste (or type) the formula, replacing [Total Amount] with your actual column name:

  [Total Amount] * 0.2
  

• Rename the new column (e.g., "20% of Total") in the field at the top of the dialog, then click OK.
• Click Close & Load to apply the changes back to your Excel table.

Power BI #

• Go to the Data view (the leftmost icon that looks like a table).
• Select your target table from the Fields pane.
• Click the Modeling tab, then choose New Column.
• In the formula bar (which acts as the expression builder), enter:

  20% of Total = 'Your Table Name'[Total Amount] * 0.2
  

  Replace 'Your Table Name' and [Total Amount] with your actual table and column names.
• Press Enter, and the new column will appear in your table.

Microsoft Access #

• Open your Access table in Datasheet View.
• Go to the Fields tab, then click Calculated Field (under the Add & Delete group).
• Select Number from the dropdown to open the expression builder.
• Enter the formula:

  [Total Amount] * 0.2
  

• Name your new column (e.g., "20% Value") in the Field Name box, then click OK.

Quick Tips #

• If your column name has spaces or special characters, always wrap it in square brackets (like [Total Amount USD]).
• Double-check that your original column is formatted as a number/currency—if it’s text, the calculation won’t work.

Let me know if you’re using a specific tool I didn’t cover, and I can adjust the steps for you!

内容的提问来源于stack exchange，提问作者Cøded Numbers