I am re-writng a perl program using python. In the perl program, it’s using perl database interface (DBI) to perform Oracle database operations. For example, DBI->connect to connect a database, and then prepare() the sql query and then execute() the query and fetch() results. I am wondering if Python has similar official module or other means to do the same things? I am using python 2.4 and 2.6 on two different RHEL 6.3 envs. Thanks in advance!
For SQLite3, there is the built-in sqlite3 module: http://docs.python.org/2/library/sqlite3.html
For PostgreSQL, there is psycopg2: http://initd.org/psycopg/
For MySQL, there is MySQLdb: http://mysql-python.sourceforge.net/MySQLdb.html
For MS SQL Server, there is pyodbc: http://code.google.com/p/pyodbc/
...or http://code.google.com/p/pymssql/
For Oracle:
https://wiki.python.org/moin/Oracle
http://www.oracle.com/technetwork/articles/dsl/python-091105.html
http://cx-oracle.sourceforge.net
PEP249, which #falsetru has mentioned, is more like an abstract description of a what a the API of a standards-conformant Python DB driver should look like. It is however in a way similar to DBI in that many (if not most or all) DB drivers for Python do have a very similar API, just like how DBI allows you to connect to many RDBMSes using a uniform API.
PLUG: take a look at Pony ORM also—it's an awesome new ORM with Oracle support: http://ponyorm.com.
Currently Pony supports 4 types of databases: 'sqlite', 'mysql', 'postgresql' and 'oracle'
It supports Python versions 2.5 or greater, but you can just use pythonz, pyenv to easily install any Python version without root privileges, or Conda.
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So I am doing a assignment which is to connect to a database and do operations on it. For that I have chosen sqlite3 and for connecting to the database I found the ODBC driver for python is pyodbc.
My questions are, what is the difference between using pyodbc and doing it using the library sqlite3, i.e., import sqlite3 ? And is the pyodbc driver integrated in sqlite3?
pyodbc is an API that allows you to interact with any database that provides provides a odbc driver for it's database. If you use the SQLite library directly and one day want to switch to another database, you will have to revise your code to either use pyodbc or the database specific API for the database you are migrating to.
You can alternatively connect to SQLite using pyodbc by using the SQLite pyodbc driver. See response here: Connect to SQLite3 server using PyODBC, Python
The big advantage of using Python's built-in sqlite3 module is that it is built-in; there are no other dependencies. If your app uses pyodbc and SQLite ODBC then both of those external components must be available for the application to function.
If this is a personal project then you can obviously install what is necessary, but if this is ever going to be widely deployed then you will need to deal with the additional requirements if you choose pyodbc. Specifically, your [Python] app can register a dependency on pyodbc such that pip install your_app also installs pyodbc, but it cannot (practically) accommodate the requirement for the SQLite ODBC driver automatically so your installation instructions will need to address that.
And is the pyodbc driver integrated in sqlite3?
No. The SQLite ODBC driver is completely separate from both Python [sqlite3] and pyodbc.
I'm wondering if there is any built-in way in Python to test a MySQL server connection. I know I can use PyMySQL, MySQLdb, and a few others, but if the user does not already have these dependencies installed my script will not work? How can I write a Python script to test a MySQL connection without requiring external dependencies?
Python distributions do not include support for MySQL, which is only available by installing a third-party module such as PyMySQL or MySQLdb. The only relational support included in Python is for the SQLite database (in the shape of the sqlite3 module).
There is, however, nothing to stop you distributing a third-party module as a part of your application, thereby including the support your project requires. PyMySQL would probably be the best choice because, being pure Python, it will run on any platform and give you best portability.
I am trying to build a tool that one step of it is connecting to MySQL database.
Just I am so confused about ODBC. If I want to build a cross platform connector by python, should I use python connector or ODBC connector?
I know JDBC, but ODBC stands for Open Database Connectivity. It looks like more compatible.
Could anyone help me clarify that? Thank you very much.
Python has its own DB API v2.0 abstraction layer to connect to databases (it serves the same purpose of ODBC or JDBC but for Python). You should use one of the DB API v2.0 compliant oursql, MySQLdb or PyMySQL packages to connect to MySQL from Python. All these packages are cross platform and will work on Linux, Windows and MacOS X. oursql, and MySQLdb are wrappers for libmysql and PyMySQL is a pure Python implementation.
Note that there are DB API v2.0 implementations (like pyodbc) that provide ODBC connectivity, so conceptually you could connect to MySQL via ODBC, but this would have inferior performance than the above mentioned "native" drivers because of the extra abstraction layers.
I'd like to query a MySQL database using Python, but evidently the MySQLdb package requires a huge toolchain of MySQL stuff to be separately installed.
How can I query a MySQL database using a Python script without installing a bunch of unnecessary MySQL stuff, including conferring MySQL server capability on the client machine?
I don't love Perl, but it appears that the DBI package allows a Perl script to interface with MySQL without any MySQL stuff external to the package. I'm looking for something similar for Python.
You need to find a pure mysql python library. I have seen a couple over the last couple months. A quick google search yoelded pymysql. It has a large following on github. It looks promising. Pymysql is a pure python mysql client.
https://github.com/petehunt/PyMySQL
MySQLdb is just one of the available database drivers. It requires all that extra installation stuff, because it compiles c extensions and is one of the faster options.
There are a handful of other database drivers, some of which are pure-python.
The SqlAlchemy project has one of the more up-to-date collections of database drivers:
http://docs.sqlalchemy.org/en/latest/core/engines.html
PyMysql is a pure python driver, so it won't need to be built against the local MySql library.
I need to write a python application with use both of the mysql and sql server is there
a general python module or library that can access both mysql and sql server as DBI with perl or should i use 2 libraries and if yes which libraries do you recommend .
I guess you are looking for SQLAlchemy. You will probably need some time getting into it, but it is invaluable once you have covered the basics.
SQLAlchemy acts as a frontend to other, database-specific libraries using the Python DB-API -- but beyond this, it provides a query builder library that abstracts out differences between databases' SQL syntax and permits programmatic query construction while still offering the full power of SQL.
Python RDBMS modules implement DB-API.
If you are looking for which connection drivers to use, I believe the only one that well work for both [MySQL (driver here) and SQLServer (native to windows/FreeTDS for linux) is pyodbc. #igor has the right idea, though, use SQLAlchemy, you can connect to each database using different engines, but use the same code to interact with both.