ActiveRecord在簡單創建時引發重複鍵錯誤

Question

由於我不理解的原因，我得到了唯一性違規。

我有一張表用於跟蹤各種權益對象的價格。我創建或 更新在給定日期這樣一個給定的資產價格：

p = Price.where(equity_id: eq.id, date: date).first_or_create 

當我運行此，ActiveRecord的是拋出此異常：

ActiveRecord::RecordNotUnique Exception: PG::UniqueViolation: ERROR: 
duplicate key value violates unique constraint "prices_pkey" DETAIL: Key 
(id)=(4273819) already exists. 
: INSERT INTO "prices" ("created_at", "date", "equity_id", "updated_at") 
VALUES ($1, $2, $3, $4) RETURNING "id" 

即使我的代碼沒有采取任何措施指定價格 對象的主鍵應該是什麼，ActiveRecord似乎堅持重新使用現有的ID ---在 這種情況下，4273819.

如果有幫助，這裏是相當長HY回溯：

from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql_adapter.rb:780:in `exec_cache' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql/database_statements.rb:139:in `block in exec_query' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract_adapter.rb:425:in `block in log' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activesupport-4.0.0/lib/active_support/notifications/instrumenter.rb:20:in `instrument' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract_adapter.rb:420:in `log' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql/database_statements.rb:137:in `exec_query' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql/database_statements.rb:183:in `exec_insert' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:96:in `insert' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/query_cache.rb:14:in `insert' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/relation.rb:76:in `insert' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/persistence.rb:498:in `create_record' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/attribute_methods/dirty.rb:78:in `create_record' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/callbacks.rb:303:in `block in create_record' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:373:in `_run__2672223936792095331__create__callbacks' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:80:in `run_callbacks' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/callbacks.rb:303:in `create_record' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/timestamp.rb:57:in `create_record' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/persistence.rb:466:in `create_or_update' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/callbacks.rb:299:in `block in create_or_update' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:383:in `_run__2672223936792095331__save__callbacks' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:80:in `run_callbacks' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/callbacks.rb:299:in `create_or_update' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/persistence.rb:106:in `save' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/validations.rb:51:in `save' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/attribute_methods/dirty.rb:32:in `save' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/transactions.rb:270:in `block (2 levels) in save' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/transactions.rb:326:in `block in with_transaction_returning_status' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `block in transaction' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:210:in `within_new_transaction' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `transaction' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/transactions.rb:209:in `transaction' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/transactions.rb:323:in `with_transaction_returning_status' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/transactions.rb:270:in `block in save' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/transactions.rb:281:in `rollback_active_record_state!' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/transactions.rb:269:in `save' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/protected_attributes-1.0.3/lib/active_record/mass_assignment_security/persistence.rb:46:in `create' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/relation.rb:121:in `block in create' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/relation.rb:270:in `scoping' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/relation.rb:121:in `create' 
from /home/ded/.rvm/gems/ruby-2.0.0-p353@s16/gems/activerecord-4.0.0/lib/active_record/relation.rb:133:in `first_or_create' 
from /home/ded/src/s16-o-r/app/models/price_retriever.rb:130:in `block (3 levels) in digest_xch' 
from /home/ded/src/s16-o-r/app/models/price_retriever.rb:96:in `each' 
from /home/ded/src/s16-o-r/app/models/price_retriever.rb:96:in `block (2 levels) in digest_xch' 
from /home/ded/src/s16-o-r/app/models/price_retriever.rb:95:in `open' 
from /home/ded/src/s16-o-r/app/models/price_retriever.rb:95:in `block in digest_xch' 
from /home/ded/src/s16-o-r/app/models/price_retriever.rb:87:in `chdir' 
from /home/ded/src/s16-o-r/app/models/price_retriever.rb:87:in `digest_xch' 
from /home/ded/src/s16-o-r/app/models/price_retriever.rb:69:in `block in digest' 
from /home/ded/src/s16-o-r/app/models/price_retriever.rb:68:in `each' 
from /home/ded/src/s16-o-r/app/models/price_retriever.rb:68:in `digest' 
from /home/ded/src/s16-o-r/app/models/runner.rb:164:in `digest' 
from /home/ded/src/s16-o-r/app/models/runner.rb:85:in `run' 
from /home/ded/src/s16-o-r/app/models/runner.rb:54:in `block in catch_up' 
from /home/ded/src/s16-o-r/app/models/runner.rb:39:in `each' 
from /home/ded/src/s16-o-r/app/models/runner.rb:39:in `catch_up' 
from script/run.rb:15:in `<main>' 

Answer 1

聽起來像是你的數據庫是不同步的，它處理的ID分配，除非被設置明確。請參閱以下有關如何重新同步的答案。

How to reset postgres' primary key sequence when it falls out of sync?

Answer 2

與同equity_id的記錄是否存在，以及可能是你已經添加了equity_id唯一性約束在Price模型

Answer 3

Postgres的和Rails 5，重新同步通過將以下的rake任務數據庫：

ActiveRecord::Base.connection.tables.each do |t| 
    ActiveRecord::Base.connection.reset_pk_sequence!(t) 
end