Source code for luigi.contrib.mssqldb

# -*- coding: utf-8 -*-
# Copyright 2012-2015 Spotify AB
# Licensed 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
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.

import logging

import luigi

logger = logging.getLogger('luigi-interface')

    import _mssql
except ImportError:
    logger.warning("Loading MSSQL module without the python package pymssql. \
        This will crash at runtime if SQL Server functionality is used.")

[docs]class MSSqlTarget(luigi.Target): """ Target for a resource in Microsoft SQL Server. This module is primarily derived from Much of MSSqlTarget, MySqlTarget and PostgresTarget are similar enough to potentially add a RDBMSTarget abstract base class to that these classes could be derived from. """ marker_table = luigi.configuration.get_config().get('mssql', 'marker-table', 'table_updates') def __init__(self, host, database, user, password, table, update_id): """ Initializes a MsSqlTarget instance. :param host: MsSql server address. Possibly a host:port string. :type host: str :param database: database name. :type database: str :param user: database user :type user: str :param password: password for specified user. :type password: str :param update_id: an identifier for this data set. :type update_id: str """ if ':' in host:, self.port = host.split(':') self.port = int(self.port) else: = host self.port = 1433 self.database = database self.user = user self.password = password self.table = table self.update_id = update_id
[docs] def touch(self, connection=None): """ Mark this update as complete. IMPORTANT, If the marker table doesn't exist, the connection transaction will be aborted and the connection reset. Then the marker table will be created. """ self.create_marker_table() if connection is None: connection = self.connect() connection.execute_non_query( """IF NOT EXISTS(SELECT 1 FROM {marker_table} WHERE update_id = %(update_id)s) INSERT INTO {marker_table} (update_id, target_table) VALUES (%(update_id)s, %(table)s) ELSE UPDATE t SET target_table = %(table)s , inserted = GETDATE() FROM {marker_table} t WHERE update_id = %(update_id)s """.format(marker_table=self.marker_table), {"update_id": self.update_id, "table": self.table}) # make sure update is properly marked assert self.exists(connection)
[docs] def exists(self, connection=None): if connection is None: connection = self.connect() try: row = connection.execute_row("""SELECT 1 FROM {marker_table} WHERE update_id = %s """.format(marker_table=self.marker_table), (self.update_id,)) except _mssql.MSSQLDatabaseException as e: # Error number for table doesn't exist if e.number == 208: row = None else: raise return row is not None
[docs] def connect(self): """ Create a SQL Server connection and return a connection object """ connection = _mssql.connect(user=self.user, password=self.password,, port=self.port, database=self.database) return connection
[docs] def create_marker_table(self): """ Create marker table if it doesn't exist. Use a separate connection since the transaction might have to be reset. """ connection = self.connect() try: connection.execute_non_query( """ CREATE TABLE {marker_table} ( id BIGINT NOT NULL IDENTITY(1,1), update_id VARCHAR(128) NOT NULL, target_table VARCHAR(128), inserted DATETIME DEFAULT(GETDATE()), PRIMARY KEY (update_id) ) """ .format(marker_table=self.marker_table) ) except _mssql.MSSQLDatabaseException as e: # Table already exists code if e.number == 2714: pass else: raise connection.close()