JITENDRA KUSHVAHA JITENDRA KUSHVAHA - 1 month ago 16
MySQL Question

undefined method `gsub' for nil:NilClass or how to use gsub method in rails

I want to generate an

Employee_ID
with serially, I have fixed a initial employee id in database table. the format is "E36162000", I am taking last employee id from table then extract only integer value then add one, this will be next
employee id
.

But in this gsub() method is not working, gsub method extract integer is perfectly, link Next Employee_id = E36162001

But when am i submit then error comes. I am sending code and screen sort please help me

_employee_details.html.erb - this is my view

<div class="modal-body">
<h2 class="text-center">Add <span>Employee Details</span></h2>
<div class="post-new-job head-border">
<div class="alert alert-success" role="alert" id='success-job' style='display:none;'>Employee Details is successfully added.</div>
<div class="form-body">
<%= form_for(:employee_details, :url => {:controller => 'hr', :action => 'create'}) do |f| %>
<div class="col-md-12">
<!--auto generate emp id-->
<% @last_emp_id = EmployeeDetail.select("employee_id").last %>
<% emp_id = @last_emp_id.employee_id %>
<% emp_id_sub = emp_id.gsub(/[^\d]/, '') %>
<% auto_generate_id = 'E'.to_s + (emp_id_sub.to_i + 1).to_s %>
<h1> Employee ID : <%= auto_generate_id %> </h1>


<div class="mydata">
<%= f.hidden_field :offer_letter_id, { class: 'form-control', id: 'recipient-name' } %>
</div>

<div class="form-group">
<label class="control-label">Employee ID</label>
<div class="input-group"> <span class="input-group-addon"> <i class="fa fa-user"></i> </span>
<%= f.text_field :employee_id, { :value => auto_generate_id, :disabled=>true , :required => true, placeholder: 'E12345678', class: 'form-control' } %>
</div>
</div>

<div class="form-group">
<label class="control-label">Bank Account</label>
<div class="input-group"> <span class="input-group-addon"> <i class="fa fa-university"></i> </span>
<%= f.text_field :bank_ac, {placeholder: '06464060852634865', class: 'form-control' } %>
</div>
</div>

<div class="form-group">
<label class="control-label">Bank IFSC Code</label>
<div class="input-group"> <span class="input-group-addon"> <i class="fa fa-code"></i> </span>
<%= f.text_field :bank_ifsc, {placeholder: 'SBI012356', class: 'form-control' } %>
</div>
</div>

<div class="form-group">
<label class="control-label">End of Date</label>
<div class="input-group"> <span class="input-group-addon"> <i class="fa fa-calendar"></i> </span>
<%= f.text_field :work_end_date, { placeholder: 'MM/DD/YYYY', id: 'datepicker', class:"datepicker_style" } %>
</div>
</div>

<div class="form-group">
<label class="control-label">Gender</label>
<div class="input-group"> <span class="input-group-addon"> <i class="fa fa-male fa-female"></i> </span>
<%= f.select :gender, ['Male', 'Female'], { }, class: "form-control" %>
</div>
</div>

<div class="form-group">
<label class="control-label">Spouse Name</label>
<div class="input-group"> <span class="input-group-addon"> <i class="fa fa-user"></i> </span>
<%= f.text_field :spouse_name, { placeholder: 'Father/Mother/Wife name', class: "form-control" } %>
</div>
</div> <br>

<div class="form-group">
<a><%= f.submit "Add Employee Details", :class => "btn btn-primary" %></a>
</div>
</div>
<div class="col-md-2"></div>
<%- end -%>
</div>
</div>
</div>


employee_details.rb - this is my model

class EmployeeDetail < ActiveRecord::Base
belongs_to :user
validates :offer_letter_id, presence: true
end


hr_controller.rb - this is my controler

class HrController < ApplicationController
def new
@employees = EmployeeDetail.new
end

# edit employee information
def edit
@employees = EmployeeDetail.find(params[:id])
end

def create
@employees = EmployeeDetail.new(employee_params)
if @employees.save
redirect_to :action => 'internal_employee_page'
else
redirect_to :action => 'internal_employee_page'
end
end

def show
@employees = EmployeeDetail.find(params[:id])
end

def update
@employees = EmployeeDetail.find(params[:id])

if @employees.update(employee_params)
redirect_to :action => 'internal_employee_page'
else
redirect_to :action => 'internal_employee_page'
end
end

private

def employee_params
params.require(:employee_details).permit(:offer_letter_id, :employee_id, :bank_ac, :bank_ifsc, :spouse_name, :gender, :work_end_date)
end
end


my layout View
enter image description here

**Error in this line **


<% emp_id_sub = emp_id.gsub(/[^\d]/, '') %>



error is
enter image description here

When am i Click on submit button then error is generate but data is save in employee_details table except Employee_Id

Answer

You might not have the emp_id. Try changing the code to,

<% @last_emp_id = EmployeeDetail.select("employee_id").last %>
<% emp_id = @last_emp_id.employee_id  %>
<% emp_id_sub = emp_id.present? ? emp_id.gsub(/[^\d]/, '') : ''%>
<% auto_generate_id = emp_id_sub.length > 0 ? ? ('E'.to_s + (emp_id_sub.to_i + 1).to_s) : "" %>
<h1> Employee ID : <%= auto_generate_id %> </h1>

checking the presence of emp_id and then emp_id_sub

Update: Added a sample query using select as per comment of @mudasobwa

2.3.1 :015 > @user = User.select("email").last
  User Load (0.5ms)  SELECT  `users`.`email` FROM `users`  ORDER BY `users`.`id` DESC LIMIT 1

 => #<User id: nil, email: "test@ead.com"> 

2.3.1 :016 > email = @user.email
 => "test@ead.com"