Question

我正在尝试将变量supplier传递给我的sql语句的where子句。它保存变量，因为当我点击链接时，它会在url中显示所选供应商。我只是不知道在声明中放什么来让它从视图中获取变量。

型号：

def self.find_supplier
find_by_sql(["SELECT s.supplier, s.productcode, s.description, CAST(SUM(l.amount) as UNSIGNED) AS amount
FROM softwares s
LEFT JOIN licenses l ON s.id=l.software_id
WHERE s.supplier = ? AND l.amount > 0
GROUP BY s.supplier, s.vendor, s.title, s.edition", :supplier)
end

查看：

<% @softwares.each do |l| %>
<li>
<%= link_to "#{l.supplier}", :controller =>'softwares', :action => 'export_supplier', :supplier => l.supplier %>
</li>
<% end %>

控制器：

def export_supplier
@software = Software.find_supplier
software = CSV.generate do |csv|

# for the headers of the csv file
  csv << ["Quantity", "Item Number", "Item Description"]
  # the chosen rows from the database
  @software.each do |s|
    csv << [s.amount, s.productcode, s.description, s.supplier]
  end
end
send_data(software, :type => 'text/csv', :filename => 'software.csv')
end

Answer 1

find_by_sql(["SELECT s.supplier, s.productcode, s.description, CAST(SUM(l.amount) as UNSIGNED) AS amount

FROM软件 LEFT JOIN许可证l ON s.id = l.software_id 什么s.supplier =？和l.amount＆gt; 0 GROUP BY s.supplier，s.vendor，s.title，s.edition“，params [：supplier]）

我假设find_by_sql在你的控制器中，“export_supplier”方法。在这里你应该得到params [：supplier]

使用rails将变量传递给SQL语句

1 个答案: