因此，我有一个Redshift数据库，其中包含足够的表，这值得花我的时间来构建前端，以使其比仅键入SQL命令更容易查询。
理想情况下，我可以通过将数据库连接到Rails应用程序来做到这一点（因为我对Rails有一定的经验）。我不确定如何将远程Redshift数据库连接到本地Rails应用程序，或者如何使activerecord与redshift一起使用。
有人有任何建议/资源来帮助我入门吗？如果有一些预制的选项比Rails容易，我可以使用其他选项将Redshift数据库连接到前端。
#app/models/data_warehouse.rb
class DataWarehouse < ActiveRecord::Base
establish_connection "redshift_staging"
#or, if you want to have a db per environment
#establish_connection "redshift_#{Rails.env}"
end
请注意，我们连接的是5439，而不是默认的5432，因此我指定了端口此外，我指定了一个模式beta，这是我们用于不稳定聚合的功能，您可以在每个环境中使用如上所述的不同数据库，或者使用各种模式，并将其包含在ActiveRecord的搜索路径中
#config/database.yml
redshift_staging:
adapter: postgresql
encoding: utf8
database: db03
port: 5439
pool: 5
schema_search_path: 'beta'
username: admin
password: supersecretpassword
host: db03.myremotehost.us #your remote host here, might be an aws url from Redshift admin console
### OPTION 2，直接PG连接
class DataWarehouse < ActiveRecord::Base
attr_accessor :conn
def initialize
@conn = PG.connect(
database: 'db03',
port: 5439,
pool: 5,
schema_search_path: 'beta',
username: 'admin',
password: 'supersecretpassword',
host: 'db03.myremotehost.us'
)
end
end
[DEV] main:0> redshift = DataWarehouse
E, [2014-07-17T11:09:17.758957 #44535] ERROR -- : PG::InsufficientPrivilege: ERROR: permission denied to set parameter "client_min_messages" to "notice" : SET client_min_messages TO 'notice'
(pry) output error: #<ActiveRecord::StatementInvalid: PG::InsufficientPrivilege: ERROR: permission denied to set parameter "client_min_messages" to "notice" : SET client_min_messages TO 'notice'>
更新：
https://github.com/fiksu/activerecord-redshift-adapter
原因1：ActiveRecord postgresql适配器设置client_min_messages原因2：适配器还尝试设置时区，redshift不允许（http://docs.aws.amazon.com/redshift/latest/dg/c_redshift-and-postgres- sql.html）原因3：即使您更改ActiveRecord中前两个错误的代码，也会遇到其他错误，这些错误抱怨Redshift正在使用Postgresql 8.0，这时我继续使用适配器，它将重新访问并更新以后我会发现更好的东西。
#Gemfile:
gem 'activerecord4-redshift-adapter', github: 'aamine/activerecord4-redshift-adapter'
#config/database.yml
redshift_staging:
adapter: redshift
encoding: utf8
database: db03
port: 5439
pool: 5
username: admin
password: supersecretpassword
host: db03.myremotehost.us
timeout: 5000
#app/models/base_aggregates_redshift_test.rb
#Model named to match my tables in Redshift, if you want you can set_table like I have commented out below
class BaseAggregatesRedshiftTest < ActiveRecord::Base
establish_connection "redshift_staging"
self.table_name = "beta.base_aggregates_v2"
end
[DEV] main:0> redshift = BaseAggregatesRedshiftTest.first
D, [2014-07-17T15:31:58.678103 #43776] DEBUG -- : BaseAggregatesRedshiftTest Load (45.6ms) SELECT "beta"."base_aggregates_v2".* FROM "beta"."base_aggregates_v2" LIMIT 1
#app/models/base_aggregates_redshift_test.rb
class BaseAggregatesRedshiftTest < ActiveRecord::Base
set_table "beta.base_aggregates_v2"
ActiveRecord::Base.establish_connection(
adapter: 'redshift',
encoding: 'utf8',
database: 'staging',
port: '5439',
pool: '5',
username: 'admin',
password: 'supersecretpassword',
search_schema: 'beta',
host: 'db03.myremotehost.us',
timeout: '5000'
)
end
#in console, abbreviated example of first record, now it's using the new name for my redshift table, just assuming I've got the record at base_aggregates_redshift_tests because I didn't set the table_name
[DEV] main:0> redshift = BaseAggregatesRedshiftTest.first
D, [2014-07-17T15:09:39.388918 #11537] DEBUG -- : BaseAggregatesRedshiftTest Load (45.3ms) SELECT "base_aggregates_redshift_tests".* FROM "base_aggregates_redshift_tests" LIMIT 1
#<BaseAggregatesRedshiftTest:0x007fd8c4a12580> {
:truncated_month => Thu, 31 Jan 2013 19:00:00 EST -05:00,
:dma => "Cityville",
:group_id => 9712338,
:dma_id => 9999
}
祝你好运@johncorser！
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