Class: OracleRaw

Inherits:
Object
  • Object
show all
Defined in:
lib/oracle_raw.rb

Overview

This is a Ruby library for interfacing with an Oracle Database using pooled OCI8 raw connections (ruby-oci8.rubyforge.org/en/). It uses ActiveRecord Oracle Enhanced adapter (github.com/rsim/oracle-enhanced) for connection pooling.

Installation

gem install oracle_raw

Usage

Consult the README.

Additional information

ActiveRecord and ConnectionPool documentation:

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(tnsnames, schema, password, pool_size = 1, global_options = {}) ⇒ OracleRaw

Establishes a connection with the given connection parameters, and sets global options.

tnsnames = '(DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SID = TEST)))'



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# File 'lib/oracle_raw.rb', line 65

def initialize(tnsnames, schema, password, pool_size = 1, global_options = {})
	ActiveRecord::Base.establish_connection(:adapter  => "oracle_enhanced", 
						:username => schema, :password => password, 
						:database => tnsnames, :pool => pool_size)
	@global_options = global_options 
end

Instance Attribute Details

#global_options ⇒ Object

Global options are readable and writable.



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# File 'lib/oracle_raw.rb', line 59

def global_options
  @global_options
end

Instance Method Details

#close ⇒ Object

Closes all connections in the connection pool.



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# File 'lib/oracle_raw.rb', line 74

def close
	ActiveRecord::Base.connection_pool.disconnect!
end

#query(sqlquery, parameters = [], options = {}) ⇒ Object

Depending whether the :metadata option is :none or :all, returns either a plain result set or a map of the following kind:

{ :count => rowcount, :columns => colnames, :data => data, :date => date, :duration => duration }

Exception are propagated to the caller.



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# File 'lib/oracle_raw.rb', line 92

def query(sqlquery, parameters = [], options = {})

	with_connection { |conn|

		starttime = Time.new; data = []

		cursor = conn.parse(sqlquery)
		cursor.max_array_size = 100
		cursor.bind_parameters(parameters) if parameters
		cursor.exec_with_prefetch(5000)

		case options[:item_format] || @global_options[:item_format]

			when :hash then

				case options[:amount] || @global_options[:amount]

					when :first_row then data = cursor.fetch_hash()
					else while r = cursor.fetch_hash(); data << r;  end 
				end
			else 
				case options[:amount] || @global_options[:amount]

					when :single_value then temp = cursor.fetch(); data = (temp ? temp[0] : nil)
					when :first_row then data = cursor.fetch()
					else while r = cursor.fetch(); data << r; end
				end
		end

		case options[:metadata] || @global_options[:metadata]

			when :all then
				colnames = cursor.get_col_names.each do |n| n.downcase! end 
				rowcount = cursor.row_count
				cursor.close
				{:count => rowcount, :columns => colnames, :data => data, :date => starttime, :duration => Time.new - starttime}
			when :plain then
				cursor.close
				data
			else	
				cursor.close
				{:data => data}
		end
	}
end

#with_connection ⇒ Object

Yields a raw connection to the block argument. Example:

db.with_connection { |c| c.exec("insert into students (last_name, first_name) values ('Kruskal-Wallis', 'Lucy')") }



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# File 'lib/oracle_raw.rb', line 82

def with_connection
	ActiveRecord::Base.connection_pool.with_connection { |conn| yield conn.raw_connection }
end