在PostgreSQL中使用Sequel gem插入一个数组
我在代码中创建了一个包含以下模式的表
DB.create_table :Pokemon do primary_key :id String :first_name String :last_name String :email String :zipcode String :company_name String :google_profile String :skype String :phone String :about String :linkedin_profile_url String :company_url column :needs , 'Text[]' column :offering , 'Text[]' end 为了需要和提供我插入一个字符串数组与以下代码
pokes=DB[:Pokemon]; off=['hello1' , 'hello2'] nee= ['need1' , 'need2'] pokes.insert(:first_name => 'abcd' ,:last_name => 'mehandiratta', :offering => off , :needs => nee)
当我运行它我得到一个错误
PG::Error: ERROR: column "offering" is of type text[] but expression is of type record (Sequel::DatabaseError) LINE 1: ...fering", "needs") VALUES ('abcd', 'mehandiratta', ('hello1',... ^ HINT: You will need to rewrite or cast the expression. from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/postgres.rb:145:in `execute_query' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/database/logging.rb:33:in `log_yield' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/postgres.rb:145:in `execute_query' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/postgres.rb:132:in `execute' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/postgres.rb:111:in `check_disconnect_errors' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/postgres.rb:132:in `execute' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/postgres.rb:413:in `_execute' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/postgres.rb:242:in `execute' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/postgres.rb:425:in `check_database_errors' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/postgres.rb:242:in `execute' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/database/connecting.rb:236:in `synchronize' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/connection_pool/threaded.rb:104:in `hold' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/database/connecting.rb:236:in `synchronize' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/postgres.rb:242:in `execute' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/dataset/actions.rb:801:in `execute' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/postgres.rb:525:in `fetch_rows' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/dataset/actions.rb:860:in `returning_fetch_rows' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/dataset/actions.rb:341:in `insert' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/shared/postgres.rb:1060:in `insert' from /var/lib/gems/1.8/gems/sequel-3.43.0/lib/sequel/adapters/shared/postgres.rb:1069:in `insert' from hello.rb:10
任何人都可以告诉一个合适的方法如何在Sequel gem中插入数组以及如何在列中添加Text数组
你需要使用Sequel的pg_array扩展，请参阅http://sequel.rubyforge.org/rdoc-plugins/files/lib/sequel/extensions/pg_array_rb.html
正如错误所说，只需将Array表达式转换为字符串，如下所示：
pokes.insert(:first_name => 'abcd' ,:last_name => 'mehandiratta', :offering => off.to_s , :needs => nee.to_s)
在您的数据库配置中：
DB.extension :pg_array
然后只需将每个数组转换为PGArray类型：
pokes.insert(:first_name => 'abcd' ,:last_name => 'mehandiratta', :offering => Sequel.pg_array(off) , :needs => Sequel.pg_array(nee))
@Jeremy Evans的回答提供了一个指向文档的链接，如果使用core-extensions扩展，它将包含更简洁的方法。