rails中validates方法
1.不为空:validates :name,:presence=>{:message=>'blank is not allowed'}
2.唯一性：validates :name,:uniqueness:{:message=>'already exist!',:case_sensitive=>false}#case_sensitive区分大小写
3.长度：validates :name,length:{in: 6..20,:message=>'must in 6-20 byte'}
??? 最小长度:minimum=>5，最大长度:maximum=>100
4.格式：validates :name,:format:{with: /[a-z]/,message=>'must contain at least one lower case character'}
5.范围：validates :country,:inclusion:{in:['China','USA','Jpan','Mexico'],:message=>'must one of China USA Jpan Mexico '}
6.数字：validates :graduate,:numericality:{:allow_nil=>true,greater_than: 1920,less_than_or_equal_to:Time.now.year}
?
7.validates :description,presence:true,if: :require_description_presence?
?def require_description_presence?
????? self.can_send_mail
?end
?这个validates :description,presence: true只有在require_description_presence?方法返回true的时候才会起作用
?
8.validate :description_length_words
?def description_length_words
? ? unless self.description.blank? then
?????? num_words = self.description.split.length
? ? ?? if num_words < 5 then
? ? ? ?? self.errors.add(:description,'must be at least 5 words long')
? ? ?? elsif num_words > 50
????????? self.errors.add(:description,'must be at most 50 words long')
??????? end
??? end
end
?
validates_exclusion_of 是和validates_inclusion_of相反的！转自：http://www.cnblogs.com/perish/archive/2012/09/14/2685180.html