通过关联查询从 has_many 获取数据

Question

class Employee < ActiveRecord::Base
  has_many :sim_employees, dependent: :destroy
  has_many :sims, through: :sim_employees
end

在我的 sim_employees table 我有 employee_id sim_d 和 is_local::boolean.

id employee_id sim_d  is_local
1    1           2      1
2    1           3      0
3    1           5      0
4    2           1      0
5    2           8      0

所以现在我的要求是

employees/index.html.erb

<%@employees.each do |employee|%>

 <%=employee.name%>
 # here I need a query if employee.id  is_local is 1 for all employee than it will show local. If it is a combination of both 1 and 0 than it will show local/std if its 0 then it will show std. Please let me know how I will fetch this data from sim_employees table here.
<%end%>

现在我需要一个查询，如果 employee.id is_local 对所有员工都是 1，那么它将显示本地。如果它是 1 和 0 的组合，那么它会显示 local/std 如果它是 0 那么它会显示 std。请告诉我如何从 sim_employees table 获取这些数据。提前致谢。

Answer 1

def of_call_type
    call_types = self.sim_employees.map(&:is_local)
    if call_types.include?(true) and call_types.include?(false)
        "Local/STD"
    elsif call_types.include?(true)
        "Local"
    else
        "STD"
    end
end

把这个方法写在employee.rb

可见

<%@employees.each do |employee|%>

 <%= employee.name%>
 <%= employee.of_call_type %>
<%end%>

通过关联查询从 has_many 获取数据

query to fetch data from has_many through association

mysql

ruby-on-rails

has-many-through