ruby-on-rails – Rails 3.1,Postgres 9.1.4,hstore未知运算符错

类似于Postgres HStore Errors – Unknown Operator但据我所知,我已经安装了hstore扩展.我已经删除了数据库并从迁移重建它而没有错误,但规格仍然失败.

Mac OS X 10.8.2
Rails 3.1.10
psql (PostgreSQL) 9.1.4

user.rb

has_many :targets

def complete_targets
  targets.where("data @> (:key => :value)",key: 'complete',value: 'true')
end

targets.rb

belongs_to :user
serialize :data,ActiveRecord::Coders::Hstore

setup_hstore迁移：

class SetupHstore < ActiveRecord::Migration
  def self.up
    execute "CREATE EXTENSION IF NOT EXISTS hstore"
  end

  def self.down
    execute "DROP EXTENSION IF EXISTS hstore"
  end
end

添加数据列迁移：

class AddDataToRecords < ActiveRecord::Migration
  def change
    add_column :records,:data,:hstore
  end
end

添加索引迁移：

class AddHstoreIndexes < ActiveRecord::Migration
  def up
    execute "CREATE INDEX records_gin_data ON records USING GIN(data)"
  end

  def down
    execute "DROP INDEX records_gin_data"
  end
end

错误：

ActiveRecord::StatementInvalid:
PG::Error: ERROR:  operator does not exist: unknown => unknown
LINE 1: ...records"."user_id" = 244 AND (data @> ('complete' => 'true')...

尝试通过直接查询创建扩展时的Navicat输出：

CREATE EXTENSION hstore Error : ERROR:  extension "hstore" already exists