创建时nil id的postgres错误

Question

编辑2 -

我认为这个问题与将类的primary_key设置为tagid有关，这将导致MySQL自动增加id值而不是postgres。不是100％肯定。请求帮助

---

我们有一个MySQL Rails应用程序，我们正在考虑迁移到Postgres。在我们播种的地方有一部分我们有以下内容：

class Tab < ActiveRecord::Base
  self.primary_key = "tagid"

  def self.rebuild_db
    terms=self.terms
    Tag.delete_all
    terms.each do |term|
      Tag.create! tagid: term[:tag_id], phrase: term[:phrase], tag_string: term[:tag_string]
    end
  end

从控制台调用时，出现以下错误：

>     [1] pry(main)> Tag.rebuild_db
>       SQL (12.9ms)  DELETE FROM "tags"
>        (0.3ms)  BEGIN
>       SQL (2.3ms)  INSERT INTO "tags" ("created_at", "id", "is_location_type", "phrase", "tag_string", "tagid", "updated_at")
> VALUES ($1, $2, $3, $4, $5, $6, $7) RETURNING "tagid"  [["created_at",
> Tue, 17 Mar 2015 09:31:27 PDT -07:00], ["id", nil],
> ["is_location_type", nil], ["phrase", "food"], ["tag_string", "-1-"],
> ["tagid", 1], ["updated_at", Tue, 17 Mar 2015 09:31:27 PDT -07:00]]
>        (0.2ms)  ROLLBACK
>     ActiveRecord::StatementInvalid: PG::NotNullViolation: ERROR:  null value in column "id" violates not-null constraint
>     DETAIL:  Failing row contains (null, food, 2015-03-17 16:31:27.235545, 2015-03-17 16:31:27.235545, null, 1, -1-).
>     : INSERT INTO "tags" ("created_at", "id", "is_location_type", "phrase", "tag_string", "tagid", "updated_at") VALUES ($1, $2, $3, $4,
> $5, $6, $7) RETURNING "tagid"

我明显看到id = nil，但我不确定我是否做错了。这是我们迄今为止唯一的问题所以我希望这是一个简单易行的问题。为什么我会收到此错误，我将如何解决？ THX

表结构如下：

embers_dev=# \d+ tags
                                                            Table "public.tags"
      Column      |            Type             |                     Modifiers                     | Storage  | Stats target | Description 
------------------+-----------------------------+---------------------------------------------------+----------+--------------+-------------
 id               | integer                     | not null default nextval('tags_id_seq'::regclass) | plain    |              | 
 phrase           | character varying(255)      |                                                   | extended |              | 
 created_at       | timestamp without time zone | not null                                          | plain    |              | 
 updated_at       | timestamp without time zone | not null                                          | plain    |              | 
 is_location_type | boolean                     |                                                   | plain    |              | 
 tagid            | integer                     |                                                   | plain    |              | 
 tag_string       | character varying(255)      | default ''::character varying                     | extended |              | 
Indexes:
    "tags_pkey" PRIMARY KEY, btree (id)

编辑1

[3] pry(main)> Tag.where(id: nil)
  Tag Load (0.4ms)  SELECT "tags".* FROM "tags" WHERE "tags"."id" IS NULL
=> []
[4] pry(main)>