How to mass update parent from child list view

Question

I need help with a controller extension to retrieve and update parent records from a list view. We have a child object called Patient_Session__c that has a lookup to parent called Patient_c and want to use a visualforce page to update the parent records in mass edit mode from a list view of the child records. Here's the extension I am using

public with sharing class updatePatientInfo {
    public Patient_Session__c pgn;
    public Patient__c patient; 
    public updatePatientInfo(ApexPages.StandardController controller) {
        this.pgn = (Patient_Session__c)controller.getRecord();
        this.patient = [SELECT Id,Name,Patient_Description__c,A_1__c,A_Frequency__c,B_1__c,B1_Frequency__c,B2_Frequency__c,C_1__c,C1_Frequency__c,C2_Frequency__c,D_1__c,D1_Frequency__c,D2_Frequency__c,X__c FROM Patient__c WHERE ID = :ApexPages.currentPage().getParameters().get('id')];
    }
    public PageReference saveRecord() {
            update patient;
    update pgn;  
        return null;
    }
 }

When I try to save the visualforce page I get this error

"Error: Unknown constructor 'updatePatientInfo.updatePatientInfo()"

I am new to apex so any help would be greatly appreciated

Answer 1

From your code:

public updatePatientInfo(ApexPages.StandardController controller)

and your error:

"Error: Unknown constructor 'updatePatientInfo.updatePatientInfo()"

I can say the following:

you don't have updatePatientInfo constructor that takes no arguments. Your only constructor needs 1 argument of type ApexPages.StandardController