Class: Ensql::SequelAdapter

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Adapter
Defined in:
lib/ensql/sequel_adapter.rb

Overview

Wraps a Sequel::Database to implement the Adapter interface for Sequel. You may want to utilize the relevant Sequel extensions to make the most of database-specific deserialization and other features. By default, uses the first database in Sequel::Databases. Other databases can be passed to the constructor.

require 'sequel'
DB = Sequel.connect('postgres://localhost/mydb')
DB.extend(:pg_json)
Ensql.adapter = Ensql::SequelAdapter.new(DB)

To stream rows, configure streaming on the connection and use Ensql::SQL#each_row

 DB = Sequel.connect('postgresql:/')
 DB.extension(:pg_streaming)
 DB.stream_all_queries = true
 Ensql.adapter = Ensql::SequelAdapter.new(DB)
 Ensql.sql("select * from large_table").each_row do  |row|
   # This now yields each row in single-row mode.
   # The connection cannot be used for other queries while this is streaming.
 end

See Also:

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Adapter

#fetch_first_column, #fetch_first_field, #fetch_first_row

Constructor Details

#initialize(db = first_configured_database) ⇒ SequelAdapter

Returns a new instance of SequelAdapter.

Parameters:

  • db (Sequel::Database) (defaults to: first_configured_database) 


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# File 'lib/ensql/sequel_adapter.rb', line 65

def initialize(db = first_configured_database)
  @db = db
end

Class Method Details

.pool(db) ⇒ PoolWrapper

Wrap the raw connections from a Sequel::Database connection pool. This allows us to safely checkout the underlying database connection for use in a database specific adapter.

Ensql.adapter = MySqliteAdapter.new(SequelAdapter.pool)

Parameters:

  • db (Sequel::Database)

Returns:



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# File 'lib/ensql/sequel_adapter.rb', line 58

def self.pool(db)
  PoolWrapper.new do |client_block|
    db.pool.hold(&client_block)
  end
end