未定义数组的方法"%“

Question

来自Controller +Error的代码：

def search_conditions
    conditions = []
    if !params[:player_name].nil? && !params[:player_name].empty?
      conditions << ["lower(players.name) LIKE ?", "#{params[:player_name].downcase}%"]
    end
    conditions
end

def index
    @games = Game.joins([:player_one, :player_two]).where(search_conditions)
end

undefined method `%' for ["lower(players.name) LIKE ?", "test%"]:Array
Stack Trace:
activerecord (3.2.6) lib/active_record/sanitization.rb:121:in `sanitize_sql_array'
activerecord (3.2.6) lib/active_record/sanitization.rb:28:in `sanitize_sql_for_conditions'
activerecord (3.2.6) lib/active_record/relation/query_methods.rb:324:in `build_where'
activerecord (3.2.6) lib/active_record/relation/query_methods.rb:136:in `where'
app/controllers/game_controller.rb:5:in `index'

查看堆栈跟踪，我搜索了活动记录源，并能够在sanitize_sql_array方法中找到导致问题的行：

statement % values.collect { |value| connection.quote_string(value.to_s) }

现在，我对ruby的了解还不够多，无法确切知道这行代码是做什么的。我最初认为它与字符串中的百分号有关，但删除它仍然会导致相同的错误。我甚至还尝试通过创建多维数组来完全构造字符串，但仍然得到相同的错误。

Answer 1

您正在向where传递一个数组数组，而不仅仅是一个数组。这意味着statement被设置为一个数组，但它需要一个字符串(字符串上的%进行字符串格式化，例如："hello %s" % "world" => "hello world")。

conditions = []
conditions << ["lower(players.name) LIKE ?", "#{params[:player_name].downcase}%"]

  => [ ["lower(players.name) LIKE ?", "..."] ] 

更改：

conditions << ["lower(players.name) LIKE ?", "#{params[:player_name].downcase}%"]

至：

conditions.push "lower(players.name) LIKE ?", "#{params[:player_name].downcase}%"