rails-postgresql

问题 I was using Mysql database before and decided to switch to Postgresql and now, when I run my tests using rspec, I getting a lot of warnings and notices. WARNING: there is already a transaction in progress NOTICE: there is no transaction in progress should has link "Suspender" WARNING: there is already a transaction in progress NOTICE: there is no transaction in progress should has css "title" with text "Suspensão de anúncio" WARNING: there is already a transaction in progress NOTICE: there is

问题 This should be SO simple. I want to retrieve the nextval of a sequence... it's not a default value... it's not a primary key... it's not a foreign key. In rare cases, I need a sequence number for a user supplied value. I've tried the following: @nextid = ActiveRecord::Base.connection.execute("SELECT nextval('xscrpt_id_seq')") and what I get back is: #<PG::Result:0x007fe668a854e8 @connection=#<PG::Connection:0x00000003aeff30>> And by using @nextid[0]["nextval"] I can get the correct value, but

问题 I have a problem with timezones and a postgresql db (Rails 3.0.4, PostgreSQL 9.0). I'm using a custom scope, in which I append some conditions, do joins etc.pp. The problem is, that Rails don't convert the times to my local timezone. Here is the code of the scope: scope :with_activities_within_range_in_week, lambda{ |latMin, lngMin, latMax, lngMax, date| select("date_trunc('day', activities.starting_at) as date, count(activities.id) as value ") \ .within(latMin, lngMin, latMax, lngMax) \

问题 I have followed this really helpful tutorial: http://blog.willj.net/2011/05/31/setting-up-postgresql-for-ruby-on-rails-development-on-os-x/ I would really like to run rails new myapp and have the postgres db set up automatically. Is there any way I can do that using a Rails application template or something similar? 回答1: On a unix based system: sudo -u postgres createuser -d -R -P APPNAME sudo -u postgres createdb -O APPNAME APPNAME You can create a script and put it somewhere in your $PATH

问题 This question already has answers here : PostgreSQL -must appear in the GROUP BY clause or be used in an aggregate function (4 answers) Closed 5 years ago . This is my query. ShopifyOrderLineItem.select("shopify_order_line_items.*, sum(amount) as total_price, sum(quantity) as total_quantity").where(:vendor_id => vendor_id).group("shopify_order_line_items.title") I'm getting the following exception. PG::GroupingError: ERROR: column "shopify_order_line_items.id" must appear in the GROUP BY

问题 In PostgreSQL, I created a new table and assigned a new sequence to the id column. If I insert a record from the PostgreSQL console it works but when I try to import a record from from Rails, it raises an exception that it is unable to find the associated sequence. Here is the table: \d+ user_messages; Table "public.user_messages" Column | Type | Modifiers | Storage | Description -------------+-----------------------------+------------------------------------------------------------+---------

问题 SELECT ARRAY[1,2,3] - ARRAY[5,NULL,6] I am using contrib _int.sql package for array operations in postgresql 8.4 In the above query there is a NULL in right hand side array. Because of this NULL value, it throws an error: "ERROR: array must not contain nulls" Can anyone help me to remove the null values from the array? 回答1: 1) Arrays can contain NULL values in PostgreSQL 8.4+ db=# SELECT ARRAY[5,NULL,6]; array ------------ {5,NULL,6} 2) But you cannot subtract one ARRAY from another in

问题 We have a single-tenant database architecture at the moment with MySQL running upward of 100 databases. We switch database connection on subdomain using the Apartment gem and all is dandy! However, we have a requirement now to create so-called "Umbrella" clients which can access all the data from a group of our existing clients. I don't see this as immediately feasible with our single-tenant database architecture (I looked into it and querying multiple MySQL databases just seemed hellish), so

问题 I have an app that uses the Ransack gem and I'm converting it from Mysql to Postgres. In an instance where the sort column is from an associated table and the distinct option is set to true, Postgres throws this error: PG::InvalidColumnReference: ERROR: for SELECT DISTINCT, ORDER BY expressions must appear in select list The Ransack github page says that, in a case like this, "you're on your own." What's the best - any! - strategy for handling this scenario? q = Contact.includes(:contact_type