Question

我尝试使用pg_search的函数：trigram来查找与我在数据库中存储的名称相似的名称。不幸的是，由于我还在学习SQL，这个错误对我来说有点太多了。

我的卡片型号：

class Card < ApplicationRecord
  include PgSearch
  pg_search_scope :spelled_like,
                  :against => :name,
                  :using => :trigram
end

我尝试在rails C中做什么：

2.4.1 :005 > c = "Timeslream Navigator"
 => "Timeslream Navigator" 
2.4.1 :006 > Card.spelled_like(c)
  Card Load (1.9ms)  SELECT  "cards".* FROM "cards" INNER JOIN (SELECT "cards"."id" AS pg_search_id, (ts_rank((to_tsvector('simple', coalesce("cards"."name"::text, ''))), (to_tsquery('simple', ''' ' || 'Timeslream' || ' ''') && to_tsquery('simple', ''' ' || 'Navigator' || ' ''')), 0)) AS rank FROM "cards" WHERE (((coalesce("cards"."name"::text, '')) % 'Timeslream Navigator'))) AS pg_search_6ac9a32c0ca8e84e5bf0c3 ON "cards"."id" = pg_search_6ac9a32c0ca8e84e5bf0c3.pg_search_id ORDER BY pg_search_6ac9a32c0ca8e84e5bf0c3.rank DESC, "cards"."id" ASC LIMIT $1  [["LIMIT", 11]]
ActiveRecord::StatementInvalid: PG::UndefinedFunction: ERROR:  operator does not exist: text % unknown
LINE 1: ...rds" WHERE (((coalesce("cards"."name"::text, '')) % 'Timeslr...

澄清 - 答案应该是Times TR eam Navigator（它确实存在于我的数据库中）

Postgres给了我一个提示：

HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
: SELECT  "cards".* FROM "cards" INNER JOIN (SELECT "cards"."id" AS pg_search_id, (ts_rank((to_tsvector('simple', coalesce("cards"."name"::text, ''))), (to_tsquery('simple', ''' ' || 'Timeslream' || ' ''') && to_tsquery('simple', ''' ' || 'Navigator' || ' ''')), 0)) AS rank FROM "cards" WHERE (((coalesce("cards"."name"::text, '')) % 'Timeslream Navigator'))) AS pg_search_6ac9a32c0ca8e84e5bf0c3 ON "cards"."id" = pg_search_6ac9a32c0ca8e84e5bf0c3.pg_search_id ORDER BY pg_search_6ac9a32c0ca8e84e5bf0c3.rank DESC, "cards"."id" ASC LIMIT $1

但是当我试着打电话的时候，我得到了另一个在这一点上没有告诉我的错误：

SyntaxError: (irb):7: syntax error, unexpected tCONSTANT, expecting end-of-input
  "cards".* FROM "cards" INNER JOIN (SELECT "cards"."id" AS 
                              ^

卡架构：

ActiveRecord::Schema.define(version: 2018_05_31_102526) do

  # These are extensions that must be enabled in order to support this database
    enable_extension "plpgsql"
    enable_extension "pg_trgm"

  create_table "cards", force: :cascade do |t|
    t.string "name"
    t.string "set"
    t.float "price"
    t.string "image"
    t.string "type_line"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

end

有什么想法吗？

Answer 1

回答我自己的问题：

pg_search is awesome!
为了使用trigram功能，你显然必须安装它。
我的问题是，我直接在psql中安装它，但没有在我的Rails应用程序中运行正确的迁移。

以下是允许我修复问题并开始享受trigram功能的迁移代码段：

class InstallPgTrgmContribPackage < ActiveRecord::Migration[5.2]
    def up
    execute "CREATE EXTENSION pg_trgm;"
  end

  def down
    execute "DROP EXTENSION pg_trgm;"
  end
end

Answer 2

我的问题有点不同。即使我的扩展已经安装，我也会在 AWS 环境中遇到这个错误，而不是较低的环境。所以我放弃了扩展并重新创建了它。
那行得通。这是我的错误：

<块引用>

PG::UndefinedFunction：错误：操作符不存在：未知 <% text 由 pg_search gem 使用 trigrams 引起。

或者你可以禁用使用三元组，但我想保留它们，所以我一直在研究

ActiveRecord :: StatementInvalid：PG :: UndefinedFunction：ERROR：运算符不存在：text％unknown

2 个答案: