text: # -*- coding: utf-8 -*-
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  # Licensed to the Apache Software Foundation (ASF) under one
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  # distributed with this work for additional information
  # regarding copyright ownership.  The ASF licenses this file
  # to you under the Apache License, Version 2.0 (the
  # "License"); you may not use this file except in compliance
  # with the License.  You may obtain a copy of the License at
  #
  #   http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing,
  # software distributed under the License is distributed on an
  # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  # KIND, either express or implied.  See the License for the
  # specific language governing permissions and limitations
  # under the License.
  
  import logging
  
  from airflow.contrib.hooks.vertica_hook import VerticaHook
  from airflow.hooks.mysql_hook import MySqlHook
  from airflow.models import BaseOperator
  from airflow.utils.decorators import apply_defaults
  
  from contextlib import closing
  
  import unicodecsv as csv
  from tempfile import NamedTemporaryFile
  
  
  class VerticaToMySqlTransfer(BaseOperator):
      """
      Moves data from Vertica to MySQL.
  
      :param sql: SQL query to execute against the Vertica database
      :type sql: str
      :param vertica_conn_id: source Vertica connection
      :type vertica_conn_id: str
      :param mysql_table: target MySQL table, use dot notation to target a
          specific database
      :type mysql_table: str
      :param mysql_conn_id: source mysql connection
      :type mysql_conn_id: str
      :param mysql_preoperator: sql statement to run against MySQL prior to
          import, typically use to truncate of delete in place of the data
          coming in, allowing the task to be idempotent (running the task
          twice won't double load data)
      :type mysql_preoperator: str
      :param mysql_postoperator: sql statement to run against MySQL after the
          import, typically used to move data from staging to production
          and issue cleanup commands.
      :type mysql_postoperator: str
      :param bulk_load: flag to use bulk_load option.  This loads MySQL directly
          from a tab-delimited text file using the LOAD DATA LOCAL INFILE command.
          This option requires an extra connection parameter for the
          destination MySQL connection: {'local_infile': true}.
      :type bulk_load: bool
      """
  
      template_fields = ('sql', 'mysql_table', 'mysql_preoperator',
          'mysql_postoperator')
      template_ext = ('.sql',)
      ui_color = '#a0e08c'
  
      @apply_defaults
      def __init__(
              self,
              sql,
              mysql_table,
              vertica_conn_id='vertica_default',
              mysql_conn_id='mysql_default',
              mysql_preoperator=None,
              mysql_postoperator=None,
              bulk_load=False,
              *args, **kwargs):
          super(VerticaToMySqlTransfer, self).__init__(*args, **kwargs)
          self.sql = sql
          self.mysql_table = mysql_table
          self.mysql_conn_id = mysql_conn_id
          self.mysql_preoperator = mysql_preoperator
          self.mysql_postoperator = mysql_postoperator
          self.vertica_conn_id = vertica_conn_id
          self.bulk_load = bulk_load
  
      def execute(self, context):
          vertica = VerticaHook(vertica_conn_id=self.vertica_conn_id)
          mysql = MySqlHook(mysql_conn_id=self.mysql_conn_id)
  
          tmpfile = None
          result = None
  
          selected_columns = []
  
          count = 0
          with closing(vertica.get_conn()) as conn:
              with closing(conn.cursor()) as cursor:
                  cursor.execute(self.sql)
                  selected_columns = [d.name for d in cursor.description]
  
                  if self.bulk_load:
                      tmpfile = NamedTemporaryFile("w")
  
                      logging.info("Selecting rows from Vertica to local file " + str(tmpfile.name) + "...")
                      logging.info(self.sql)
  
                      csv_writer = csv.writer(tmpfile, delimiter='\t', encoding='utf-8')
                      for row in cursor.iterate():
                          csv_writer.writerow(row)
                          count += 1
  
                      tmpfile.flush()
                  else:
                      logging.info("Selecting rows from Vertica...")
                      logging.info(self.sql)
  
                      result = cursor.fetchall()
                      count = len(result)
  
                  logging.info("Selected rows from Vertica " + str(count))
  
          if self.mysql_preoperator:
              logging.info("Running MySQL preoperator...")
              mysql.run(self.mysql_preoperator)
  
          try:
              if self.bulk_load:
                  logging.info("Bulk inserting rows into MySQL...")
                  with closing(mysql.get_conn()) as conn:
                      with closing(conn.cursor()) as cursor:
                          cursor.execute("LOAD DATA LOCAL INFILE '%s' INTO TABLE %s LINES TERMINATED BY '\r\n' (%s)" % (tmpfile.name, self.mysql_table, ", ".join(selected_columns)))
                          conn.commit()
                  tmpfile.close()
              else:
                  logging.info("Inserting rows into MySQL...")
                  mysql.insert_rows(table=self.mysql_table, rows=result, target_fields=selected_columns)
              logging.info("Inserted rows into MySQL " + str(count))
          except:
              logging.error("Inserted rows into MySQL 0")
              raise
  
          if self.mysql_postoperator:
              logging.info("Running MySQL postoperator...")
              mysql.run(self.mysql_postoperator)
  
          logging.info("Done")
  