arel

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How to do "where exists" in Arel

How开发者_StackOverflow do you do a query that includes a \"where exists\" in Arel? For example on a query like this to show all the suppliers with at least one order:[详细]

2023-03-09 17:19 分类：问答
Automated way to select all columns of joined table in ActiveRecord?

Wondering with the upgrade to Arel, if ActiveRecord yet supports an automated way to select in the columns from joined tables, without having to explicitly list them in a select clause.[详细]

2023-03-08 11:08 分类：问答
Is there any way to use AREL for custom associations?

model Post # ActiveRecord associations have tons of options that let # you do just about anything like:[详细]

2023-02-28 11:26 分类：问答
Rails 3 NoMethodError: undefined method `name' for nil:NilClass

Whenever i tried to use Table.create :a=>\"a\", :b=>\"b\" or tab开发者_StackOverflow=Table.new tab.a=\"a\"[详细]

2023-02-26 01:04 分类：问答
What does AREL stand for?

What does AREL stand f开发者_开发技巧or? I couldn\'t find what\'s the meaning of this acronym anywhere.This?https://github.com/nkallen/arel\"A RELational algebra\"[详细]

2023-02-25 08:50 分类：问答
Overriding methods in ActiveRecord::QueryMethods

I want to be able to override certain methods in ActiveRecord::QueryMethods for educational and experimental reasons.[详细]

2023-02-23 02:57 分类：问答
How to convert SQL to Arel?

Is there a wa开发者_如何学Cy to convert the MATCH and AGAINST parts to Arel? I could not find anything about it in the Arel source code.[详细]

2023-02-22 13:28 分类：问答
Is there a way to invert an ActiveRecord::Relation query?

Let\'s say we have the following: irb> Post.where(:hidden => true).to_sql =&开发者_C百科gt; \"SELECT `posts`.* FROM `posts` WHERE posts.hidden = 1\"[详细]

2023-02-17 05:39 分类：问答
Want to find records with no associated records in Rails

Consider a simple association... class Person has_many :friends end class Friend belongs_to :person end What is the cleanest way to get all persons that have NO friends in ARel and/or meta_where?[详细]

2023-02-17 05:31 分类：问答
Rails3 & ActiveRecord::Relation - Arel and OR

I have some scopes definied in a Model called Events. Now I need join them using OR operator. I’m using Rails3 and I’m a bit confused with ActiveRelation & Arel and how and how I should use this[详细]

2023-02-16 09:41 分类：问答