sequel

= Sequel: The Database Toolkit for Ruby

Sequel is a simple, flexible, and powerful SQL database access
toolkit for Ruby.

* Sequel provides thread safety, connection pooling and a concise
  DSL for constructing SQL queries and table schemas.
* Sequel includes a comprehensive ORM layer for mapping
  records to Ruby objects and handling associated records.
* Sequel supports advanced database features such as prepared
  statements, bound variables, savepoints, two-phase commit,
  transaction isolation, primary/replica configurations, and
  database sharding.
* Sequel currently has adapters for ADO, Amalgalite, 
  IBM_DB, JDBC, MySQL, Mysql2, ODBC, Oracle,
  PostgreSQL, SQLAnywhere, SQLite3, TinyTDS, and Trilogy.

== Resources

Website :: https://sequel.jeremyevans.net
RDoc Documentation :: https://sequel.jeremyevans.net/rdoc
Source Code :: https://github.com/jeremyevans/sequel
Bug tracking (GitHub Issues) :: https://github.com/jeremyevans/sequel/issues
Discussion Forum (GitHub Discussions) :: https://github.com/jeremyevans/sequel/discussions
Archived Discussion Forum (sequel-talk Google Group) :: https://www.mail-archive.com/sequel-talk@googlegroups.com/

If you have questions about how to use Sequel, please ask on
GitHub Discussions.
Only use the bug tracker to report
bugs in Sequel, not to ask for help on using Sequel.

To check out the source code:
  
  git clone git://github.com/jeremyevans/sequel.git
  
=== Contact

If you have any comments or suggestions please post to the Google group.

== Installation

  gem install sequel
  
== A Short Example

  require 'sequel'
  
  DB = Sequel.sqlite # memory database, requires sqlite3
  
  DB.create_table :items do
    primary_key :id
    String :name
    Float :price
  end
  
  items = DB[:items] # Create a dataset
  
  # Populate the table
  items.insert(name: 'abc', price: rand * 100)
  items.insert(name: 'def', price: rand * 100)
  items.insert(name: 'ghi', price: rand * 100)
  
  # Print out the number of records
  puts "Item count: #{items.count}"
  
  # Print out the average price
  puts "The average price is: #{items.avg(:price)}"

== The Sequel Console

Sequel includes an IRB console for quick access to databases (usually referred to as <tt>bin/sequel</tt>). You can use it like this:

  sequel sqlite://test.db # test.db in current directory

You get an IRB session with the Sequel::Database object stored in DB.

In addition to providing an IRB shell (the default behavior), bin/sequel also has support for migrating databases, dumping schema migrations, and copying databases.  See the {bin/sequel guide}[rdoc-ref:doc/bin_sequel.rdoc] for more details.

== An Introduction

Sequel is designed to take the hassle away from connecting to databases and manipulating them. Sequel deals with all the boring stuff like maintaining connections, formatting SQL correctly and fetching records so you can concentrate on your application.

Sequel uses the concept of datasets to retrieve data. A Dataset object encap