我尝试通过2个团队搜索比赛,我尝试了几种语法,但没有帮助...
模型匹配:
class Match < ApplicationRecord
belongs_to :home, class_name: 'Team', foreign_key: :home_id
belongs_to :away, class_name: 'Team', foreign_key: :away_id
end
模型团队:
class Team < ApplicationRecord
has_many :home_matches, class_name: 'Match', foreign_key: :home_id
has_many :away_matches, class_name: 'Match', foreign_key: :away_id
# Fields: name
end
我尝试过这样的事情:
Match.includes(:home, :away).where(homes: { name: 'Germany' }, aways: {name: 'China'})
错误:
ActiveRecord :: StatementInvalid(PG :: UndefinedTable:错误:缺少 表“ homes”的FROM子句条目)
答案 0 :(得分:2)
选项1。
在Rails Console查询puts Match.joins(:home, :away).to_sql
中进行检查。
您可能会得到如下结果:
SELECT "matches".* FROM "matches" INNER JOIN "teams" ON "teams"."id" = "matches"."home_id" INNER JOIN "teams" "away_matches" ON "away_matches"."id" = "matches"."away_id"
如果是这样,请使用类似查询
Match.joins(:home, :away).where(teams: { name: 'Germany' }, away_matches: {name: 'China'})
选项2。
尝试类似的查询
Match.where(home: Team.where(name: 'Germany'), away: Team.where(name: 'China'))
您还可以预查找团队ID:
home_id = Team.find_by(name: 'Germany').id
away_id = Team.find_by(name: 'China').id
Match.where(home_id: home_id, away_id: away_id)