Python database interfaces
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This document provides an overview of Python database interfaces and APIs for connecting to relational and non-relational databases. It discusses popular database drivers like pyodbc, MySQLdb, and psycopg, which provide interfaces to SQL databases like SQL Server, MySQL, Oracle, and PostgreSQL. It also mentions ORM frameworks like Django that provide higher-level database access.
![pyodbc
• Selecting Some Data
Execute query then fetch results.
cursor.execute("select user_id, user_name from users")
row = cursor.fetchone()
print 'name:', row[1] # access by column index
print 'name:', row.user_name # or access by name
cursor.execute("select user_id, user_name from users")
rows = cursor.fetchall()
for row in rows:
print row.user_id, row.user_name
Python database interfaces Fall 2012](https://image.slidesharecdn.com/pythondatabaseinterfaces-121218151106-phpapp02/85/Python-database-interfaces-4-320.jpg)
Python database interfaces
- 2. Generic Database Interfaces and APIs • ODBC Support o pyodbc o mxODBC • ADO Support o adodbapi • JDBC Support o Integrated in Jython Python database interfaces Fall 2012
- 3. pyodbc • Connect to a Database Make a direct connection to a database and create a cursor. import pyodbc cnxn = pyodbc.connect('DRIVER={SQL Server}; SERVER=localhost; DATABASE=testdb; UID=user; PWD=pass') cursor = cnxn.cursor() Python database interfaces Fall 2012
- 4. pyodbc • Selecting Some Data Execute query then fetch results. cursor.execute("select user_id, user_name from users") row = cursor.fetchone() print 'name:', row[1] # access by column index print 'name:', row.user_name # or access by name cursor.execute("select user_id, user_name from users") rows = cursor.fetchall() for row in rows: print row.user_id, row.user_name Python database interfaces Fall 2012
- 5. pyodbc • Inserting or deleting Execute query then commit changes. cursor.execute("insert into products(id, name) values ('pyodbc', 'awesome')") cnxn.commit() deleted = cursor.execute("delete from products where id <> 'pyodbc'").r cnxn.commit() Python database interfaces Fall 2012
- 6. Interfaces for Relational Database Systems • General Purpose Database Systems • Database Systems for Embedding Into Applications Python database interfaces Fall 2012
- 7. General Purpose Database Systems • Microsoft SQL Server • Oracle • MySQL • IBM DB2 • PostgreSQL • Firebird (and Interbase) • Informix • SAP DB (also known as "MaxDB") • … Python database interfaces Fall 2012
- 8. • mssql o MS SQL Server module for Python • pymssql o A fast MS SQL server client library for Python directly using C API instead of ODBC. Python database interfaces Fall 2012
- 9. • cx_Oracle o Lite Oracle DB Server module for Python • DCOracle2 o Advanced Python DB API 2.0 adapter for Oracle from Zope company. Python database interfaces Fall 2012
- 10. • MySQLdb o The most famous library for connecting MySQL in python. • PyMySQL o Pure-Python MySQL client library. Python database interfaces Fall 2012
- 11. MySQLdb • Benefits: o Very fast and optimized ( written in C) o Has big community o Defense SQL injection o very efficient import MySQLdb conn = mysql.connect(‘localhost’, ‘username’, ‘password’, ‘db name’) cursor = conn.cursor() cursor.execute(‚Example query‛) cursor.commit() #needed for insert and delete Python database interfaces Fall 2012
- 12. • Ibm_db o Python support for IBM DB2 and IBM Informix • PyDB2 o Pure-Python DB2 interface library. Python database interfaces Fall 2012
- 13. • Psycopg o The most popular PostgreSQL adapter for the Python • PyGreSQL o Open-source Python module that interfaces to a PostgreSQL database Python database interfaces Fall 2012
- 14. Interfaces for Non-Relational Database Systems • MetaKit • ZODB • Berkeley DB • Durus • Atop Python database interfaces Fall 2012
- 15. Native Python Databases • Buzhug o buzhug is a fast, portable, pure-Python database engine, using a pythonic non-SQL syntax for all operations. • SnakeSQL o SnakeSQL is a pure Python SQL database written to remove the dependence of the Python Web Modules on 3rd party drivers for non-Python databases. Python database interfaces Fall 2012
- 16. Django is a high-level Python Web framework that encourages rapid development and clean, pragmatic design. Python database interfaces Fall 2012
- 17. Set database server DATABASES = { 'default': { 'ENGINE': 'django.db.backends.’ # Add 'postgresql_psycopg2', 'mysql', 'sqlite3' or 'oracle'. 'NAME': 'main_db.db', # Or path to database file if using sqlite3. 'USER': '', 'PASSWORD': '', 'HOST': '', # Set to empty string for localhost. 'PORT': '', # Set to empty string for default. } } Python database interfaces Fall 2012
- 18. Using multiple database • DATABASES = { 'default': { 'NAME': 'app_data', 'ENGINE': 'django.db.backends.postgresql_psycopg2', 'USER': 'postgres_user', 'PASSWORD': 's3krit' }, 'users': { 'NAME': 'user_data', 'ENGINE': 'django.db.backends.mysql', 'USER': 'mysql_user', 'PASSWORD': 'priv4te' } } Python database interfaces Fall 2012
- 19. Resources • Expert Python Programming Python database interfaces Fall 2012
- 20. Resources • wiki.python.org • www.djangoproject.com Python database interfaces Fall 2012
- 21. Python database interfaces Fall 2012