提问人:Carlos Morales 提问时间:4/11/2014 最后编辑:Rajesh OmanakuttanCarlos Morales 更新时间:8/30/2017 访问量:28452
如何在 rails 视图中遍历数组?
How can I iterate through an array in rails view?
问:
我在 MySql 中进行了查询,但在 Rails 和 mysql2 gem 中工作。
信息如下:
http://sqlfiddle.com/#!2/9adb8/6
查询工作正常,没有问题,并显示以下结果:
UNIT V1 A1 N1 V2 A2 N2 V3 A3 N3 V4 A4 N4 V5 A5 N5
LIFE 2 0 0 1 2 0 0 0 0 0 0 0 0 0 0
ROB 0 1 0 0 1 2 0 0 0 0 0 0 0 0 0
- 为 rails 2.3.8 安装了 mysql2 gem
gem install mysql2 -v0.2.6
·创建控制器:
class PolicyController < ApplicationController
def index
@result = ActiveRecord::Base.connection.execute("select distinct @sql := concat('SELECT pb.name as unit,',group_concat(concat('SUM(CASE WHEN p.state =0 AND ce.id=',id,' THEN 1 ELSE 0 END ) AS v',id,',SUM(CASE WHEN p.state =1 AND ce.id=',id,' THEN 1 ELSE 0 END ) AS a',id,',SUM(CASE WHEN p.state =2 AND ce.id=',id,' THEN 1 ELSE 0 END ) AS n',id)),' FROM cia_ensures ce LEFT JOIN policies p on ce.id = p.cia_ensure_id INNER JOIN policy_business_units pb ON pb.id = p.policy_business_unit_id INNER JOIN comercial_areas ca ON ca.id = pb.comercial_area_id AND ca.id=1 Group by p.policy_business_unit_id') from cia_ensures where id in(1,2,3,4,5);")
@result2 = ActiveRecord::Base.connection.execute("prepare stmt from @sql;")
@result3 = ActiveRecord::Base.connection.execute("execute stmt;")
end
end
日志如下:
SQL (0.9ms) select distinct @sql := concat('SELECT pb.name as unit,',group_concat(concat('SUM(CASE WHEN p.state =0 AND ce.id=',id,' THEN 1 ELSE 0 END ) AS v',id,',SUM(CASE WHEN p.state =1 AND ce.id=',id,' THEN 1 ELSE 0 END ) AS a',id,',SUM(CASE WHEN p.state =2 AND ce.id=',id,' THEN 1 ELSE 0 END ) AS n',id)),' FROM cia_ensures ce LEFT JOIN policies p on ce.id = p.cia_ensure_id INNER JOIN policy_business_units pb ON pb.id = p.policy_business_unit_id INNER JOIN comercial_areas ca ON ca.id = pb.comercial_area_id AND ca.id=1 Group by p.policy_business_unit_id') from cia_ensures where id in(1,2,3,4,5);
SQL (0.9ms) prepare stmt from @sql;
SQL (0.2ms) execute stmt;
这是视图(工作正常且没有问题,但似乎太长,写了几次相同的代码)
<table>
<% @result3.each do |policy| %>
<tr>
<td><%= policy[0] %></td>
<td><%= policy[1] %></td>
<td><%= policy[2] %></td>
<td><%= policy[3] %></td>
<td><%= policy[4] %></td>
<td><%= policy[5] %></td>
...
</tr>
<%end%>
</table>
我尝试使用 inspect,但它在一个 td 中显示所有信息,而不是在每个 td 上显示所有信息:
<% @result3.each do |policy| %>
<tr>
<td align="center"><%= policy.inspect %></td>
</tr>
<%end%>
我怎样才能在不写很多行的情况下展示所有这些?
是否可以在一行中做到这一点?不写 <%= policy[#NUMBER] %>
请有人可以帮我解决这个问题吗?
我将不胜感激。
答:
18赞
Igor Pantović
4/11/2014
#1
嗯,可能误解了你的问题,因为它看起来很简单,你是想缩短这个吗?
改变:
<td><%= policy[0] %></td>
<td><%= policy[1] %></td>
<td><%= policy[2] %></td>
<td><%= policy[3] %></td>
<td><%= policy[4] %></td>
<td><%= policy[5] %></td>
自:
<% policy.each do |p| %>
<td><%= p %></td>
<% end %>
2赞
toniedzwiedz
4/11/2014
#2
只需遍历每个对象中的每个集合即可。policy
<table>
<% @result3.each do |policy| %>
<tr>
<%policy.each do |item| %>
<td><%= item %></td>
<%end%>
</tr>
<%end%>
</table>
4赞
Rajdeep Singh
4/11/2014
#3
执行此操作
<% @result3.each do |policy| %>
<tr>
<% policy.each { |p| raw "<td>#{p}</td>" } %>
</tr>
<%end%>
评论
each
@result3