How to insert a custom object that inherits from the object Account with custom fields

Question

I want to save the fields BillingAddress, ShippingAddress and a custom field "FiscalAddress"

I understand that the API only have BillingAddress and ShippingAddress and I need one more.

I want insert in database (SOQL) but the logic of my script is wrong.

What corrections you should do to insert the input text fields in the Account table?

error console:

<apex:inputField> value binding '{!a.BillingStreet}'. <apex:inputField> can only be used with SObjects, or objects that are Visualforce field component resolvable.

Markup

<apex:page Controller="CustomAccount" >
    <apex:form >

        <apex:pageBlock title="Edit Contact">

            <apex:pageBlockSection columns="1">
                <apex:inputField value="{!a.BillingStreet}"/>
                <apex:inputField value="{!a.BillingCity}"/>
                <apex:inputField value="{!a.BillingState}"/>
                <apex:inputField value="{!a.BillingPostalCode}"/>

                <apex:inputField value="{!a.ShippingStreet}"/>
                <apex:inputField value="{!a.ShippingCity}"/>
                <apex:inputField value="{!a.ShippingState}"/>
                <apex:inputField value="{!a.ShippingPostalCode}"/>


                <apex:inputField value="{!a.FiscalStreet}"/>
                <apex:inputField value="{!a.FiscalCity}"/>
                <apex:inputField value="{!a.FiscalState}"/>
                <apex:inputField value="{!a.FiscalPostalCode}"/>

            </apex:pageBlockSection>
            <apex:pageBlockButtons >
                <apex:commandButton action="{!save}" value="Save"/>
            </apex:pageBlockButtons>

        </apex:pageBlock>

    </apex:form>
</apex:page>

Code

public with sharing class CustomAccount {
    public Account a { get; set; }

    public List<Account> samepage { get; set; }

    public CustomAccount(){
       a = new Account();
    }

    public PageReference save() {
       insert a;  

    }


}

Markup new version

<apex:page standardController="Account">
  <apex:form>
    <apex:pageBlock>
      <apex:pageBlockSection>
        <apex:inputField value="{!Account.BillingStreet}" />
        <apex:inputField value="{!Account.BillingCity}" />
        <apex:inputField value="{!Account.BillingState}" />
        <apex:inputField value="{!Account.BillingPostalCode}" />

        <apex:inputField value="{!Account.ShippingStreet}"/>
        <apex:inputField value="{!Account.ShippingCity}"/>
        <apex:inputField value="{!Account.ShippingState}"/>
        <apex:inputField value="{!Account.ShippingPostalCode}"/>


        <apex:inputField value="{!Account.FiscalStreet__c}" />
        <apex:inputField value="{!Account.FiscalCity__c}"/>
        <apex:inputField value="{!Account.FiscalState__c}"/>
        <apex:inputField value="{!Account.FiscalPostalCode__c}"/>

      </apex:pageBlockSection>
      <apex:pageBlockButtons>
        <apex:commandButton action="{!save}" value="Save" />
      </apex:pageBlockButtons>
    </apex:pageBlock>
  </apex:form>
</apex:page>

Answer 1

You'll need to create the fields in Setup first (Setup > Customize > Accounts > Fields or Setup > Object Manager > Account > Fields & Relationships). Once you do so, you can write your page using the StandardController:

<apex:page standardController="Account">
  <apex:form>
    <apex:pageBlock>
      <apex:pageBlockSection>
        <apex:inputField value="{!Account.BillingStreet}" />
        ... other fields ...
        <apex:inputField value="{!Account.FiscalStreet__c}" />
        ... other fields ...
      </apex:pageBlockSection>
      <apex:pageBlockButtons>
        <apex:commandButton action="{!save}" value="Save" />
      </apex:pageBlockButtons>
    </apex:pageBlock>
  </apex:form>
</apex:page>

Note that Custom Fields that you create end in __c (as demonstrated in the code). You'll want to also read about Display Field Values with Visualforce.