Question

我正在解析CSV文件并且有一个应该是布尔值的字符串列。这些值要么是＆＃39; Y＆＃39;或者＆＃39; N＆＃39;我想在回调中处理这些并插入为boolean。这是否可以使用activerecord回调？

Rails 5.0.0

CSV：

RULE_TYPE,DESCRIPTION,STANDARD_OPTION
OY,One,Y
TN,Two,N

迁移：

...
  t.boolean :standard_option
...

模型：

class OptionRule < ApplicationRecord
  before_validation :standard_option_bool
  private
  def standard_option_bool
    puts self.standard_option
    self.standard_option=="Y" ? self.standard_option=true : self.standard_option=false
  end
end

rails c

2.3.1 :001 > OptionRule.create(rule_type:'OY', description:"One", standard_option: 'Y')
   (0.1ms)  BEGIN
true
SQL (0.6ms)  INSERT INTO "option_rules" ("rule_type", "description", "standard_option", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "rule_type"  [["rule_type", "OY"], ["description", "One"], ["standard_option", false], ["created_at", 2016-07-25 10:34:06 UTC], ["updated_at", 2016-07-25 10:34:06 UTC]]
 (6.2ms)  COMMIT
=> #<OptionRule rule_type: "OY", description: "One", standard_option: false, created_at: "2016-07-25 10:34:06", updated_at: "2016-07-25 10:34:06">

请注意，它会返回＆＃39; true＆＃39;对于puts命令而不是＆＃39; Y＆＃39;。我必须认为activerecord在回调之前正在改变它。

Answer 1

是的，你可以做到。即使这样也可行

class OptionRule < ApplicationRecord
  before_validation :standard_option_bool

  private

  def standard_option_bool
    self.standard_option = standard_option == "Y"
  end
end

Answer 2

尝试为布尔列传递 1（true）和 0（false）。

class OptionRule < ApplicationRecord
  before_validation :standard_option_bool

  private
  def standard_option_bool
    self.standard_option=="Y" ? self.standard_option = 1 : self.standard_option = 0
  end
end

Answer 3

请试试这个

class OptionRule < ApplicationRecord
  before_validation :standard_option_bool

  private

  def standard_option_bool
    self.standard_option = self.standard_option == "Y" ? true : false
  end
end

Answer 4

我通过创建一个临时变量解决了这个问题。

var m1 = new UIButton(UIButtonType.System);
    m1.Frame = new RectangleF(45, -50, 230, 20);
    m1.SetTitle("Beautiful That Way", UIControlState.Normal);
    m1.TouchUpInside += (sender, e) => OpenPlayerView(PlayerOption.Stream, "mySongUrl.mp3", "Beautiful That Way" );

var m2 = new UIButton(UIButtonType.System);
    m2.Frame = new RectangleF(45, -20, 230, 20);
    m2.SetTitle("Boys In The Sky", UIControlState.Normal);
    m2.TouchUpInside += (sender, e) => OpenPlayerView(PlayerOption.Stream, "mySongUrl.mp3", "Boys In The Sky");

var m3 = new UIButton(UIButtonType.System);
    m3.Frame = new RectangleF(45, 10, 230, 20);         m3.SetTitle("Cos'é l'Amor", UIControlState.Normal);
    m3.TouchUpInside += (sender, e) => OpenPlayerView(PlayerOption.Stream, "mySongUrl.mp3", "Cos'é l'Amor");

var m4 = new UIButton(UIButtonType.System);
    m4.Frame = new RectangleF(45, 40, 230, 20);
    m4.SetTitle("Dancing Qeen", UIControlState.Normal);
    m4.TouchUpInside += (sender, e) => OpenPlayerView(PlayerOption.Stream, "mySongUrl.mp3", "Dancing Qeen");

var m5 = new UIButton(UIButtonType.System);
    m5.Frame = new RectangleF(45, 70, 230, 20);
    m5.SetTitle("Free", UIControlState.Normal);
    m5.TouchUpInside += (sender, e) => OpenPlayerView(PlayerOption.Stream, "mySongUrl.mp3", "Free");

        scrollView.AddSubview(m1);
        scrollView.AddSubview(m2);
        scrollView.AddSubview(m3);
        scrollView.AddSubview(m4);
        scrollView.AddSubview(m5);

然后设置OptionRule.standard_option_temp并让验证设置布尔值

保存前将activerecord属性设置为boolean from string

4 个答案: