## Calculate Action

The `calculate` action allows you to perform arithmetic operations on two fields and store the result in a third field. You can use the `calculate` action to perform addition, subtraction, multiplication, and division.

## Usage

The `calculate` action is used in the following format:

``````actions:
action_name:
action: calculate
fields: [field_1, field_2]
operator: operation
result: result_field
``````

Where:

• `action_name` is the name of the action.
• `field_1` is the name of the first field used in the calculation.
• `field_2` is the name of the second field used in the calculation.
• `operation` is the arithmetic operation to perform. Valid values are `ADD`, `SUBTRACT`, `MULTIPLY`, and `DIVIDE`.
• `result_field` is the name of the field where the result of the calculation will be stored.

## Example

Consider the following input:

``````item:
- quantity: 10
- price_gbp: 2.50
``````

And the following `calculate` action:

``````actions:
action: calculate
fields: [ quantity, price_gbp ]
operator: MULTIPLY
result: total_price_gbp
``````

When executed, the `calculate` action multiplies the values of the `quantity` and `price_gbp` fields, and stores the result in the `total_price_gbp` field.

The output of the `calculate` action, given the input above, would be:

``````item:
- quantity: 10
- price_gbp: 2.50
- total_price_gbp: 25.00
``````
• The `fields` array can contain any number of fields, as long as the arithmetic operation is valid.
• If any of the fields used in the calculation are missing from the input, the result will be ether unchanged (e.a. 5 multiplied by a null column would result in 5) or `null`.