ruby-on-rails - 数组的未定义方法 "%"

Question

来自 Controller 的代码 + 错误:

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，我搜索了事件记录源并且能够在 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，无法确切知道该行的作用。我认为它最初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。我什至还尝试通过创建多维数组来完全构造字符串，但我仍然遇到相同的错误。

Answer 1

您正在将一个数组数组传递到 where，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 ?", "..."] ] 

改变:

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

到:

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