当我参加锦标赛时,这是有效的,但是当我参加锦标赛时,这是有效的。它给了我:
<main>'irb(main):117:0> tournament.teams << team
(0.1ms) begin transaction
(0.0ms) commit transaction
Team Load (0.2ms) SELECT "teams".* FROM "teams" WHERE "teams"."tournament_id" = 1
ActiveRecord::StatementInvalid: SQLite3::SQLException: no such column: teams.tournament_id: SELECT "teams".* FROM "teams" WHERE "teams"."tournament_id" = 1
我想在团队和锦标赛之间建立关系,这种关系是多对多关系。我知道我必须通过连接表来完成这一操作,该连接表在下面显示的第一部分中完成。从那里,我必须分别添加团队/锦标赛模型中显示的关联。
class TeamTournamentJoinAttempt3 < ActiveRecord::Migration
def up
create_table :teams_tournaments, :id => false do |t|
t.integer "tournament_id"
t.integer "team_id"
end
add_index :teams_tournaments, ["tournament_id", "team_id"]
end
def down
drop_table :teams_tournaments
end
end
锦标赛模特:
class Tournament < ActiveRecord::Base
has_and_belongs_to_many :teams
end
团队模型:
class Team < ActiveRecord::Base
has_and_belongs_to_many :tournaments
end
现在我可以使用以下方法在rails控制台中找到一个团队和锦标赛:
tournament = Tournaments.find(1)
team = Teams.find(1)
然后我可以使用:
在两者之间建立关系team.tournaments << tournament
(0.1ms) begin transaction
(0.3ms) INSERT INTO "teams_tournaments" ("team_id", "tournament_id") VALUES (1, 1)
(123.1ms) commit transaction
热潮,我认为一切正常。但是,当我尝试以另一种方式(tournament.teams << team
)时,它不起作用给我以下错误:
tournament.teams << team
(0.1ms) begin transaction
(0.0ms) commit transaction
Team Load (0.2ms) SELECT "teams".* FROM "teams" WHERE "teams"."tournament_id" = 1
ActiveRecord::StatementInvalid: SQLite3::SQLException: no such column: teams.tournament_id: SELECT "teams".* FROM "teams" WHERE "teams"."tournament_id" = 1
答案 0 :(得分:0)
在尝试TeamTournamentJoinAttempt3
或reload!
关联后,看到belongs_to
我的赌注是在Ruby控制台中没有使用has_one
。