By using our site, you acknowledge that you have read and understand our Code Review Stack Exchange is a question and answer site for peer programmer code reviews. Ruby and Rails are slow — this argument is often used to downplay the worth of the language and the framework.
That means that if a relation hasn't been preloaded yet then it loads all its records. Checking whether a file exists or not, is one of the most basic file related tasks which you will do most of the times and thankfully Ruby's File class provides two methods called File.file? In the code for controls that are a form or class that I call to perform the insert. The Overflow Blog The best answers are voted up and rise to the top First, we check if the record exists with the EXISTS keyword.EXISTS executes the query we tell it to (the SELECT) and returns a boolean value.If it finds the record, we return 'This record already exists!' Our new ebook “CI/CD with Docker & Kubernetes” is out. Every request handler in your application probably starts with a lookup, followed by a policy check that uses multiple dependent lookups in the database.However, there are multiple ways to check the existence of a database record in Rails. Detailed answers to any questions you might have Code Review Stack Exchange works best with JavaScript enabled The following are a few ways you can check to ensure that a file or directory exists using Ruby.Returns true if the named file exists and is a regular file. However, there are multiple ways to check the existence of a database record in Rails. Stack Exchange network consists of 177 Q&A communities including We will try to look up if there has been a passed build in the last 7 days.Let’s observe the database calls produced by our calls.The first call that uses .present? API calls that worked just fine can suddenly start killing your service with a dreaded HTTP 502 response. The argument can take five forms: Integer- Finds the record with this primarykey. Learn more about Stack Overflow the company Ruby on Rails latest stable (v5.2.3) - 1 note - Class : ... Returns true if a record exists in the table that matches the id or conditions given , or false otherwise. It loads all the records from the database into memory, constructs the Active Record objects, and then finds out if the array is empty or not. The argument can take six forms: Integer - Finds the record with this primary key.

Their expressiveness and their reusability is simply great. Anybody can answer GitHub Gist: instantly share code, notes, and snippets. Loading too much data into memory, N+1 queries, lack of cached values, and the lack of proper databases indexes are the biggest culprits that cause slow requests.There are some legitimate domains where Ruby is simply too slow.
is very inefficient. Learn more about Stack Overflow the company (), File.exist? Check if URL exists in Ruby. I have a form that does an insert. COUNT(*) queries are usually efficient, and you can use them even on semi-large tables without any dangerous side effects.The third approach, exists?, is even more optimized, and it should be your first choice when checking the existence of a record. However, there are some exceptions.For example, if we are checking for the existence of an association record without any scope, any? Returns true if a record exists in the table that matches the idor conditions given, orfalse otherwise. Even though JavaScript (and node.js!) How To Check If A File or Directory Exists in Ruby November 15, 2015 2 minute read Even though JavaScript (and node.js!) Which is better? faster by one whole database call when the records are already loaded into memory:As a conclusion, my general advice is to always use exists? Our relationship is very solid now, but initially everything was very confusing due to some ducktyping and some prototypal and/or delegative misunderstanding We can use a Set to get O(1) access time at the cost of having to create a Hash representation of the array first. If it exists, I want to update the update_at datetime field. Featured on Meta