如何从table1中检索列值并将其保存在table2的列中？

Question

TABLE_1：

ID | Name | Address 
1 | prakash | 2-107, NY 
2 | rakesh | 2-109/a, NY 

TABLE_2：

emp_ID| Name | Designation 
    ? | Prakash | Software Developer 
    ? | Rakesh | Software Tester 

通过在表2中使用的名称列，我需要从表1中的ID，并将其放置在表2 。

require 'csv' 
load 'dbconnection.rb' 
require 'activerecord' 


class Employee<ActiveRecord::Base 

end 

class Designation<ActiveRecord::Base 
end 

#Employee Table Data Insertion 
CSV.foreach("C:/Users/modi/Desktop/employee.csv") do |row| 
    Employee.create!(
     # ID will be auto increement 
     :name => row[0], 
     :address => row[1], 
     ) 
    end 


#Designation Table Data Insertion 

CSV.foreach('C:/Users/modi/Desktop/designation.csv') do |row| 

    Designation.create!(
     :Emp_id #Here we need to get the id value from the Employee Table 
     :name => row[0], 
     :designation=>row[1] 
     )   
    end 

Answer 1

假设Employee不包含数据的大量，你可以这样做：

employees = Employee.all 
CSV.foreach('C:/Users/modi/Desktop/designation.csv') do |row| 
    Designation.create!(
    :Emp_id => employees.detect { |emp| emp.name == row[0] }.id # handle nil case 
    :name => row[0], 
    :designation=>row[1] 
)   
end