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 59

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 53

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 68

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 86

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

  with_connection { |conn|

    starttime = Time.new; data = []

    cursor = conn.parse(sqlquery)
    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 76

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