Introduction

sqlparse is a non-validating SQL parser for Python. It provides support for parsing, splitting and formatting SQL statements. The module is released under the terms of the New BSD license.

Visit the project page at http://python-sqlparse.googlecode.com for further information about this project.

Download & Installation

The latest released version can be obtained from the downloads page on the project’s website. To extract the source archive and to install the module on your system run

$ tar cvfz python-sqlparse-VERSION.tar.gz
$ cd python-sqlparse/
$ sudo python setup.py install

Alternatively you can install sqlparse from the Python Packge Index with your favorite tool for installing Python modules. For example when using pip run pip install sqlparse.

Getting Started

The sqlparse module provides three simple functions on module level to achieve some common tasks when working with SQL statements. This section shows some simple usage examples of these functions.

Let’s get started with splitting a string containing one or more SQL statements into a list of single statements using split():

>>> import sqlparse
>>> sql = 'select * from foo; select * from bar;'
>>> sqlparse.split(sql)
[u'select * from foo; ', u'select * from bar;']

The end of a statement is identified by the occurrence of a semicolon. Semicolons within certain SQL constructs like BEGIN ... END blocks are handled correctly by the splitting mechanism.

SQL statements can be beautified by using the format() function.

>>> sql = 'select * from foo where id in (select id from bar);'
>>> print sqlparse.format(sql, reindent=True, keyword_case='upper')
SELECT *
FROM foo
WHERE id IN
  (SELECT id
   FROM bar);

In this case all keywords in the given SQL are uppercased and the indentation is changed to make it more readable. Read Formatting of SQL Statements for a full reference of supported options given as keyword arguments to that function.

Before proceeding with a closer look at the internal representation of SQL statements, you should be aware that this SQL parser is intentionally non-validating. It assumes that the given input is at least some kind of SQL and then it tries to analyze as much as possible without making too much assumptions about the concrete dialect or the actual statement. At least it’s up to the user of this API to interpret the results right.

When using the parse() function a tuple of Statement instances is returned:

>>> sql = 'select * from "someschema"."mytable" where id = 1'
>>> parsed = sqlparse.parse(sql)
>>> parsed
(<Statement 'select...' at 0x9ad08ec>,)

Each item of the tuple is a single statement as identified by the above mentioned split() function. So let’s grab the only element from that list and have a look at the tokens attribute. Sub-tokens are stored in this attribute.

>>> stmt = parsed[0]  # grab the Statement object
>>> stmt.tokens
(<DML 'select' at 0x9b63c34>,
 <Whitespace ' ' at 0x9b63e8c>,
 <Operator '*' at 0x9b63e64>,
 <Whitespace ' ' at 0x9b63c5c>,
 <Keyword 'from' at 0x9b63c84>,
 <Whitespace ' ' at 0x9b63cd4>,
 <Identifier '"somes...' at 0x9b5c62c>,
 <Whitespace ' ' at 0x9b63f04>,
 <Where 'where ...' at 0x9b5caac>)

Each object can be converted back to a string at any time:

>>> stmt.to_unicode()
u'select * from "someschema"."mytable" where id = 1'
>>> stmt.tokens[-1].to_unicode()  # or just the WHERE part
u'where id = 1'

Details of the returned objects are described in Analyzing the Parsed Statement.

Development & Contributing

To check out the latest sources of this module run

$ hg clone http://python-sqlparse.googlecode.com/hg/ python-sqlparse

to check out the latest sources from the Mercurial repository.

Please file bug reports and feature requests on the project site at http://code.google.com/p/python-sqlparse/issues/entry or if you have code to contribute upload it to http://codereview.appspot.com and add albrecht.andi@googlemail.com as reviewer.

For more information about the review tool and how to use it visit it’s project page: http://code.google.com/p/rietveld.