You can see that there are the new fields that we’ve created within orders_rows.
Add a line and enter values into Qty and Price to see the total price automatically calculated. You can also write a value inside Total Price as the field is editable, but it will be changed automatically as soon as one of the fields called by the expression is changed.
Remember that expressions are executed in the order in which they were entered and are all recalculated as soon as a field they call is changed.
Now we insert the field Total price on the order following another way: by inserting the field directly from the scheme editor.
Open the default scheme of the Orders table, open the Actions menu, select Create field and finally select the item Bottom right Detail.