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DataLogger-Generic/web_db/mysql-connector-python-2.1.4/examples/transaction.py
2016-11-01 16:56:22 -05:00

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Python
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#!/usr/bin/env python
# -*- coding: utf-8 -*-
# MySQL Connector/Python - MySQL driver written in Python.
# Copyright (c) 2009, 2014, Oracle and/or its affiliates. All rights reserved.
# MySQL Connector/Python is licensed under the terms of the GPLv2
# <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most
# MySQL Connectors. There are special exceptions to the terms and
# conditions of the GPLv2 as it is applied to this software, see the
# FOSS License Exception
# <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
"""
Example using MySQL Connector/Python showing:
* dropping and creating a table
* using warnings
* doing a transaction, rolling it back and committing one.
"""
import mysql.connector
def main(config):
output = []
db = mysql.connector.Connect(**config)
cursor = db.cursor()
# Drop table if exists, and create it new
stmt_drop = "DROP TABLE IF EXISTS names"
cursor.execute(stmt_drop)
stmt_create = """
CREATE TABLE names (
id TINYINT UNSIGNED NOT NULL AUTO_INCREMENT,
name VARCHAR(30) DEFAULT '' NOT NULL,
cnt TINYINT UNSIGNED DEFAULT 0,
PRIMARY KEY (id)
) ENGINE=InnoDB"""
cursor.execute(stmt_create)
warnings = cursor.fetchwarnings()
if warnings:
ids = [ i for l,i,m in warnings]
output.append("Oh oh.. we got warnings..")
if 1266 in ids:
output.append("""
Table was created as MYISAM, no transaction support.
Bailing out, no use to continue. Make sure InnoDB is available!
""")
db.close()
return
# Insert 3 records
output.append("Inserting data")
names = ( ('Geert',), ('Jan',), ('Michel',) )
stmt_insert = "INSERT INTO names (name) VALUES (%s)"
cursor.executemany(stmt_insert, names)
# Roll back!!!!
output.append("Rolling back transaction")
db.rollback()
# There should be no data!
stmt_select = "SELECT id, name FROM names ORDER BY id"
cursor.execute(stmt_select)
rows = None
try:
rows = cursor.fetchall()
except mysql.connector.InterfaceError as e:
raise
if rows == []:
output.append("No data, all is fine.")
else:
output.append("Something is wrong, we have data although we rolled back!")
output.append(rows)
cursor.close()
db.close()
return output
# Do the insert again.
cursor.executemany(stmt_insert, names)
# Data should be already there
cursor.execute(stmt_select)
output.append("Data before commit:")
for row in cursor.fetchall():
output.append("%d | %s" % (row[0], row[1]))
# Do a commit
db.commit()
cursor.execute(stmt_select)
output.append("Data after commit:")
for row in cursor.fetchall():
output.append("%d | %s" % (row[0], row[1]))
# Cleaning up, dropping the table again
cursor.execute(stmt_drop)
cursor.close()
db.close()
return output
if __name__ == '__main__':
config = {
'host': 'localhost',
'port': 3306,
'database': 'test',
'user': 'root',
'password': '',
'charset': 'utf8',
'use_unicode': True,
'get_warnings': True,
}
out = main(config)
print('\n'.join(out))