Ruby on rails 在Rails控制台中发生意外行为

轨道3.2

我正在一个Rails控制台会话中，我正在尝试通过id查找一个公司。我有一个带有id列的公司表

是的

以下是我在控制台中得到的信息：

  Company Load (161.2ms)  SELECT `companies`.* FROM `companies` WHERE `companies`.`slug` = '1403045688' LIMIT 1
  EXPLAIN (162.2ms)  EXPLAIN SELECT `companies`.* FROM `companies` WHERE `companies`.`slug` = '1403045688' LIMIT 1
EXPLAIN for: SELECT  `companies`.* FROM `companies`  WHERE `companies`.`slug` = '1403045688' LIMIT 1
+----+-------------+-------+------+---------------+------+---------+------+------+-----------------------------------------------------+
| id | select_type | table | type | possible_keys | key  | key_len | ref  | rows | Extra                                               |
+----+-------------+-------+------+---------------+------+---------+------+------+-----------------------------------------------------+
|  1 | SIMPLE      | NULL  | NULL | NULL          | NULL | NULL    | NULL | NULL | Impossible WHERE noticed after reading const tables |
+----+-------------+-------+------+---------------+------+---------+------+------+-----------------------------------------------------+
1 row in set (0.20 sec)

  Company Load (1.6ms)  SELECT `companies`.* FROM `companies` WHERE `companies`.`id` = '1403045688' LIMIT 1
  EXPLAIN (80.7ms)  EXPLAIN SELECT `companies`.* FROM `companies` WHERE `companies`.`id` = '1403045688' LIMIT 1
EXPLAIN for: SELECT  `companies`.* FROM `companies`  WHERE `companies`.`id` = '1403045688' LIMIT 1
+----+-------------+-----------+-------+---------------+---------+---------+-------+------+-------+
| id | select_type | table     | type  | possible_keys | key     | key_len | ref   | rows | Extra |
+----+-------------+-----------+-------+---------------+---------+---------+-------+------+-------+
|  1 | SIMPLE      | companies | const | PRIMARY       | PRIMARY | 182     | const |    1 |       |
+----+-------------+-----------+-------+---------------+---------+---------+-------+------+-------+
1 row in set (0.08 sec)

=> #<Company id: "1403045688", name: "AAA Electric", slug: "aaa-electric-inc", created_at: "2014-06-17 22:54:48", updated_at: "2016-03-12 05:13:26">

它不应该直接按id搜索，而不是先用slug搜索吗？为什么它看起来很困惑，想要解释这个问题

当您使用find方法时，它将同时使用slug和id列来查找记录，如果您希望只按id搜索记录，则需要将代码更改为类似以下内容：

company=company.whereid:1403045688.take

当您使用find方法时，它将同时使用slug和id列来查找记录，如果您希望只按id搜索记录，则需要将代码更改为类似以下内容：

---

company=company.whereid:1403045688.拿着

你好像在用友好的宝石，是吗？如果是，您需要更新gem，因为从V5开始禁用查找器覆盖。当我在Gemfile.lock中grep for friendly_id时，我得到：friendly_id~>4.0，>=4.0.9 friendly_id 4.0.10.1 friendly_id您建议我使用gem的5.0版本吗？是的，如果不希望主键被slug.覆盖的默认行为，则始终需要指定要查询的列。您可能还需要更改其他位置的代码，因为对slug的调用已更改，例如User.friendly.findparams[：id]参见friendly_id 5具有ActiveRecord 4依赖项。我使用的是Rails 3.2。哦，是的……那么你可能不得不忍受这一点……你似乎使用了友好的id gem，是吗？如果是，您需要更新gem，因为从V5开始禁用查找器覆盖。当我在Gemfile.lock中grep for friendly_id时，我得到：friendly_id~>4.0，>=4.0.9 friendly_id 4.0.10.1 friendly_id您建议我使用gem的5.0版本吗？是的，如果不希望主键被slug.覆盖的默认行为，则始终需要指定要查询的列。您可能还需要更改其他位置的代码，因为对slug的调用已更改，例如User.friendly.findparams[：id]参见friendly_id 5具有ActiveRecord 4依赖项。我使用的是Rails 3.2.Ohh是的……那么你可能不得不忍受这一点……为什么要使用Company.whereid:1403045688而不是Company.find_by_id 1403045688？因为在5.0版本之前，FriendlyId总是会覆盖默认的finder方法来执行友好查找，而find_by_id则会被覆盖以首先按slug列进行搜索，如果没有找到记录，则id将用于搜索。为什么要使用Company.whereid:1403045688而不是Company.find_by_id 1403045688？因为在版本5.0之前，FriendlyId会重写默认的finder方法来执行友好查找，所以find_by_id会被重写为首先按slug列进行搜索，若并没有找到记录，那个么id将用于搜索。

  Company Load (161.2ms)  SELECT `companies`.* FROM `companies` WHERE `companies`.`slug` = '1403045688' LIMIT 1
  EXPLAIN (162.2ms)  EXPLAIN SELECT `companies`.* FROM `companies` WHERE `companies`.`slug` = '1403045688' LIMIT 1
EXPLAIN for: SELECT  `companies`.* FROM `companies`  WHERE `companies`.`slug` = '1403045688' LIMIT 1
+----+-------------+-------+------+---------------+------+---------+------+------+-----------------------------------------------------+
| id | select_type | table | type | possible_keys | key  | key_len | ref  | rows | Extra                                               |
+----+-------------+-------+------+---------------+------+---------+------+------+-----------------------------------------------------+
|  1 | SIMPLE      | NULL  | NULL | NULL          | NULL | NULL    | NULL | NULL | Impossible WHERE noticed after reading const tables |
+----+-------------+-------+------+---------------+------+---------+------+------+-----------------------------------------------------+
1 row in set (0.20 sec)

  Company Load (1.6ms)  SELECT `companies`.* FROM `companies` WHERE `companies`.`id` = '1403045688' LIMIT 1
  EXPLAIN (80.7ms)  EXPLAIN SELECT `companies`.* FROM `companies` WHERE `companies`.`id` = '1403045688' LIMIT 1
EXPLAIN for: SELECT  `companies`.* FROM `companies`  WHERE `companies`.`id` = '1403045688' LIMIT 1
+----+-------------+-----------+-------+---------------+---------+---------+-------+------+-------+
| id | select_type | table     | type  | possible_keys | key     | key_len | ref   | rows | Extra |
+----+-------------+-----------+-------+---------------+---------+---------+-------+------+-------+
|  1 | SIMPLE      | companies | const | PRIMARY       | PRIMARY | 182     | const |    1 |       |
+----+-------------+-----------+-------+---------------+---------+---------+-------+------+-------+
1 row in set (0.08 sec)

=> #<Company id: "1403045688", name: "AAA Electric", slug: "aaa-electric-inc", created_at: "2014-06-17 22:54:48", updated_at: "2016-03-12 05:13:26">