Find all records with at least one child in rails

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### Find all records with at least one child
Parent.join(:children).uniq.all
# or 
Parent.includes(:children).where("children.id IS NOT NULL")
# or Rails 5
Parent.left_outer_joins(:children).where.not(children: {id: nil})


### Find all records with no children
Parent.includes(:children).where(children: {id: nil})
# or Rails 5
Parent.left_outer_joins(:children).where(children: {id: nil})
Experienced Ruby on Rails and Web Developer having 11+ years experience in Ruby & Ruby on Rails framework, TTD, Rspec. Expert on Git, SVN , Git Hook, Bitbucket. I use MySQL, MongoDB , PostgreSQL & Sqlite for Database Management. In front-end development I use HTML5 / HAML, CSS3 / SCSS, javascript / coffeescript. I also know about the deploy the applications on VPS Server i.e AWS EC2, Heroku, Ditital Ocean, Hostgator, Site5, BlueHost, AWS Load Balancing, Elastic Beanstalk, AWS S3 e.t.c ☆ Frameworks ☆ Ruby on Rails, Sinatra ☆ Database ☆ - PostgreSQL, MySQL, SQLite, - MongoDB, Amazon DynamoDB,AWS RDS. ☆ Front end Techniques ☆ - ReactJS, Angular js, Node js, Javascript, JQuery, HTML, CSS - Twitter Bootstrap, Coffeescript. Why hire me? * Master degree in Computer Science * 6 years professional experiences and 10+ projects completed * Available all day long, 7 days/24 hours * Good communication skills with fluent English * Self-motivated, fast-learner and "I can do" mind * Quality insurance and fast delivery

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