Arel_Table Rails - Ruby

Are_Table is a gem for creating SQL queries in Rails. It is built on top of Arel, which is a SQL AST (Abstract Syntax Tree) manager for Ruby. Arel_Table provides an easy-to-use interface for building complex SQL statements within Ruby code.

Installation

To install Arel_Table, add the following line to your Gemfile:

gem 'arel_table'

Then, run bundle install to install the gem.

Usage

To use Arel_Table, you first need to create a new instance of Arel::Table for the database table you want to query. For example, if you have a users table in your database, you can create a new Arel::Table instance as follows:

users = Arel::Table.new(:users)

Once you have a Arel::Table instance, you can start building SQL queries using the Arel_Table syntax.

For example, to select all users from the users table, you can do the following:

query = users.project('*')

To filter the results by a specific condition, you can use the where method:

query = users.where(users[:name].eq('John'))

To join tables, you can use the join method:

orders = Arel::Table.new(:orders)
query = users.join(orders).on(orders[:user_id].eq(users[:id]))

Once you have built your query using Arel_Table, you can execute it using Rails' ActiveRecord connection:

result = ActiveRecord::Base.connection.execute(query.to_sql)

Conclusion

Arel_Table is a powerful gem for building SQL queries in Rails. It provides an easy-to-use interface for building complex statements and is built on top of Arel, which is a robust SQL AST manager for Ruby. If you need to build SQL queries in your Rails application, Arel_Table is definitely worth checking out.