6

我在使用带有sequel和 sqlite 外键约束的数据库清理器时遇到了问题。具体来说，我正在使用Capybara 集成测试的策略。:truncation

对于给定的示例架构：

CREATE TABLE users(id INTEGER PRIMARY KEY, name TEXT);
CREATE TABLE events(id INTEGER PRIMARY KEY, title TEXT);

CREATE TABLE events_users(
  user_id INTEGER,
  event_id INTEGER,

  FOREIGN KEY(user_id) REFERENCES users(id),
  FOREIGN KEY(event_id) REFERENCES events(id)
);

和续集模型：

class User < Sequel::Model
  many_to_many :events
end

class Event < Sequel::Model
  many_to_many :users
end

运行以下：

# normally this would be run in
# an rspec before(:each) for my :feature specs
DatabaseCleaner.start
DatabaseCleaner.strategy = :truncation

bob = User.create(name: "bob")
sally = User.create(name: "sally")
event = Event.create(title: "Everyone's invited")
event.users << [bob, sally]

DatabaseCleaner.clean

导致错误

SQLite3::ConstraintException: FOREIGN KEY constraint failed (Sequel::ForeignKeyConstraintViolation)

我可以通过更改我的 before 语句来禁用 foreign_keys PRAGMA 来解决这个问题：

DB.foreign_keys = false
DatabaseCleaner.start
DatabaseCleaner.strategy = :truncation

（或者不在我的表中使用 FOREIGN KEY），但这似乎是错误的，因为我想要外键约束的好处 - 或者至少我认为我这样做;）。

这是对如何使用外键约束的根本误解，还是有更好的方法来做到这一点？

4

1 回答 1

2

已经快两年了，我已经放弃尝试彻底解决这个问题T_T。

I experienced random FOREIGN KEY constraint failed issues during a recent sequel upgrade. To resolve this, I switched from DatabaseCleaner.strategy = :truncation to DatabaseCleaner.strategy = :deletion.

There's been a thorough analysis of the benefits/costs of :truncate versus :delete and the answer (at least for postgres) is it depends. So far :delete seems to be a little faster for my small testing data set.

于 2017-06-18T00:29:40.380 回答