Hi,

I have written the code but after execution of the query filds is not updating.

public with sharing class GenerateDtfCase {
//public POSDetails__c customerObj{get;set;}
Public List<Case> customerObj{get;set;}
  Public List<Employee_Master__c> Emp{get;set;}
  public String branchcode{get;set;} 
  //public String cityBranch {get;set;} 
public Date Today { get { return Date.today(); }}
    public GenerateDtfCase(ApexPages.StandardController controller) {
      try
        {
            Emp= [Select e.User__r.Id, e.User__c, e.Id, e.Branch_Code__r.BranchCode__c, e.Branch_Code__r.Cash_inCounter_Limit__c, 
                  e.Branch_Code__r.Cash_in_Safe_Limit__c, e.Branch_Code__r.Name, e.Branch_Code__c 
                  From Employee_Master__c e where User__r.Id = : UserInfo.getUserId() and Active__c= : true  limit 1];
            
            if(Emp[0].Branch_Code__r.BranchCode__c!= null)
            {
               
                branchcode=Emp[0].Branch_Code__r.Name;
            }else{
                ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.ERROR, 'No Branch mapping found in Employee master for the logged in user.  Please contact the system administrator to get it corrected.'));
            }
        }catch(exception e){
            ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.ERROR, 'No mapping record found in Employee Master for the Logged in user. Please contact the system administrator to get it corrected.'));
        }
    system.debug('branch code:'+branchcode);
    
    //customerObj = [select id, Name,Complete_Status__c,Branch_name__c,Creation_Date__c,Document_List__c,Vertical__c,Status__c,DTF_Creation_Date__c,Effective_date_of_coverage__c,Policy_No__c,proposal_Application_no__c,proposal_Name__c,Request_Type__c,Request_Type_new_del__c,Branch__c ,Supporting_Document_del__c 
    //FROM POSDetails__c WHERE Vertical__c='LI' AND Branch__r.Name =:branchcode];
    customerObj = [select id,CaseNumber,Branch_name__c,Account_Name__c,Proposal_Detail__c,Policy_Number__c,Creation_Date__c,Document_List__c,Vertical__c,DTF_Creation_Date__c,Effective_date_of_coverage__c,Request_Type__c,Supporting_Document__c 
    FROM Case WHERE Vertical__c='LI' AND RecordType.ID ='012O00000005BMS' AND created_date__c=true ];
        
//customerObj = [select id, Name, Complete_Status__c, Branch_name__c,Branch__r.Name , Creation_Date__c, Document_List__c, Vertical__c, Status__c, DTF_Creation_Date__c, Effective_date_of_coverage__c, Policy_No__c, proposal_Application_no__c, proposal_Name__c, Request_Type__c, Request_Type_new_del__c, Branch__c, Supporting_Document_del__c, OwnerId from POSDetails__c where (Vertical__c = 'LI'and Branch__r.Name =:branchcode)];
system.debug('test query branch:'+branchcode);
system.debug('test query customerObj:'+customerObj );

    }
    
    public GenerateDtfCase() {
      for(Case c: customerObj) {
          if(c.Vertical__c == 'LI')
          customerObj = [select id,CaseNumber,Branch_name__c,Account_Name__c,Proposal_Detail__c,Policy_Number__c,Creation_Date__c,Document_List__c,Vertical__c,DTF_Creation_Date__c,Effective_date_of_coverage__c,Request_Type__c,Supporting_Document__c 
    FROM Case WHERE Vertical__c='LI' AND RecordType.ID ='012O00000005BMS' AND created_date__c=true ];
               c.DTF_Creation_Date__c = System.today();
     }
     update customerObj;

    } 

}