Class: Blazer::Adapters::SqlAdapter

Inherits:
BaseAdapter show all
Defined in:
lib/blazer/adapters/sql_adapter.rb

Instance Attribute Summary collapse

Attributes inherited from BaseAdapter

#data_source

Instance Method Summary collapse

Constructor Details

#initialize(data_source) ⇒ SqlAdapter

Returns a new instance of SqlAdapter.



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# File 'lib/blazer/adapters/sql_adapter.rb', line 6

def initialize(data_source)
  super

  @connection_model =
    Class.new(Blazer::Connection) do
      def self.name
        "Blazer::Connection::#{object_id}"
      end
      establish_connection(data_source.settings["url"]) if data_source.settings["url"]
    end
end

Instance Attribute Details

#connection_model ⇒ Object (readonly)

Returns the value of attribute connection_model.



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# File 'lib/blazer/adapters/sql_adapter.rb', line 4

def connection_model
  @connection_model
end

Instance Method Details

#cost(statement) ⇒ Object 



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# File 'lib/blazer/adapters/sql_adapter.rb', line 60

def cost(statement)
  result = explain(statement)
  match = /cost=\d+\.\d+..(\d+\.\d+) /.match(result)
  match[1] if match
end

#explain(statement) ⇒ Object 



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# File 'lib/blazer/adapters/sql_adapter.rb', line 66

def explain(statement)
  if postgresql? || redshift?
    connection_model.connection.select_all("EXPLAIN #{statement}").rows.first.first
  end
rescue
  nil
end

#preview_statement ⇒ Object 



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# File 'lib/blazer/adapters/sql_adapter.rb', line 52

def preview_statement
  "SELECT * FROM {table} LIMIT 10"
end

#reconnect ⇒ Object 



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# File 'lib/blazer/adapters/sql_adapter.rb', line 56

def reconnect
  connection_model.establish_connection(settings["url"])
end

#run_statement(statement, comment) ⇒ Object 



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# File 'lib/blazer/adapters/sql_adapter.rb', line 18

def run_statement(statement, comment)
  columns = []
  rows = []
  error = nil

  begin
    in_transaction do
      set_timeout(data_source.timeout) if data_source.timeout

      result = connection_model.connection.select_all("#{statement} /*#{comment}*/")
      columns = result.columns
      cast_method = Rails::VERSION::MAJOR < 5 ? :type_cast : :cast_value
      result.rows.each do |untyped_row|
        rows << (result.column_types.empty? ? untyped_row : columns.each_with_index.map { |c, i| untyped_row[i] ? result.column_types[c].send(cast_method, untyped_row[i]) : nil })
      end
    end
  rescue ActiveRecord::StatementInvalid => e
    error = e.message.sub(/.+ERROR: /, "")
    error = Blazer::TIMEOUT_MESSAGE if Blazer::TIMEOUT_ERRORS.any? { |e| error.include?(e) }
  end

  [columns, rows, error]
end

#schema ⇒ Object 



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# File 'lib/blazer/adapters/sql_adapter.rb', line 47

def schema
  result = data_source.run_statement(connection_model.send(:sanitize_sql_array, ["SELECT table_schema, table_name, column_name, data_type, ordinal_position FROM information_schema.columns WHERE table_schema IN (?) ORDER BY 1, 2", schemas]))
  result.rows.group_by { |r| [r[0], r[1]] }.map { |k, vs| {schema: k[0], table: k[1], columns: vs.sort_by { |v| v[4].to_i }.map { |v| {name: v[2], data_type: v[3]} }} }
end

#tables ⇒ Object 



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# File 'lib/blazer/adapters/sql_adapter.rb', line 42

def tables
  result = data_source.run_statement(connection_model.send(:sanitize_sql_array, ["SELECT table_name FROM information_schema.tables WHERE table_schema IN (?) ORDER BY table_name", schemas]))
  result.rows.map(&:first)
end