Hello, 

In my lightning page, I display a list of opportunities (data retrieved from the database). I need to update the data and save it. in my page, I have the field Amount, which is calculated automatically from the multiplication of 2 other fields.
Can you help me.


cmp file:

    <aura:if isTrue="{!v.zonesList != null}">                    
                        <aura:iteration items="{!v.zonesList}" var="item" indexVar="index">
                            <div class="slds-col slds-size--1-of-6 slds-m-top_medium slds-m-left_xx-large">
                                <span><lightning:button label="{!item.name}"  value="{!item.name}"  aura:id="di"  name="di" class="{!'customButton' +index+ ' slds-size--1-of-1 slds-p-horizontal_x-small'}" /></span>
                            </div>
                            <div class="slds-col slds-size--1-of-8 slds-m-left_small">
                                <span><lightning:input type="number" aura:id="{!index}" min="0" formatter="percent-fixed"   step="0.01" name="globalObjective" label="" class="slds-p-horizontal_x-small" value="{!item.globalObjective}" /></span>
                            </div>
                            <div class="slds-col slds-size--1-of-6 slds-m-left_medium">
                                <span><lightning:input aura:id="{!index}" name="CA" label=""   disabled="true" class="slds-size--1-of-1 slds-p-horizontal_x-small" type="number" formatter="currency" step="0.01" value="{!item.turnover}" /></span>
                            </div>
                            <div class="slds-col slds-size_1-of-12 slds-m-left_small">
                                <span>
                                    <aura:if isTrue="{!index == 0}">
                                        <lightning:input aura:id="{!index}" name="PerctNewbus" label="NB"     class="slds-size--1-of-1 slds-p-horizontal_x-small" type="number"  min="0" formatter="percent-fixed" step="0.01" value="{!item.newBusiness}" />
                                        <aura:set attribute="else">
                                            <lightning:input aura:id="{!index}" name="PerctNewbus" label=""     class="slds-size--1-of-1 slds-p-horizontal_x-small" type="number"  min="0" formatter="percent-fixed" step="0.01" value="{!item.newBusiness}" />
                                        </aura:set>
                                    </aura:if>
                                </span>
                            </div>