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SQLite

URL

http://sqlite.org/

licence
Sources are uncopyrighted. Use for any purpose.
platforms
Built and tested under Linux and Win2K.

Pros

I think SQLite may be a good replacement for gadfly, because:

  • The main engine is written in C, so it should be faster than the gadfly implementation in Python
  • It's extensible in a very easy way via Python
  • It doesn't put all data in memory like gadfly does (yet you can do that if you want, just use ':memory:' as filename
  • It's very cool for small databased application, because you do not have to start an external DBMS
  • Implements almost all of SQL92

Cons

  • SQLite only supports the basic types NULL, INTEGER, FLOAT, TEXT and BLOB
  • If you want to use other types like DATE and TIME in pysqlite, you need to use its "pysqlite types mode", where things can get a little nastier.


DB API 2.0 Drivers

pysqlite

URL

http://code.google.com/p/pysqlite/

SourceForge

http://sourceforge.net/projects/pysqlite

licence
zlib/libpng License
platforms
Windows 95/98/2000/XP, POSIX, MacOS X
Python versions
2.1 or later (1.x branch)/2.3 or later (2.0 branch). Included in Python 2.5.

Extensions to DB API

  • Extensible type conversion
  • Factories for connection and cursor objects
  • row converter factory to easily and efficiently switch to a nonstandard type for rows (e. g. dicts)
  • User-defined functions and aggregates

Other Drivers

APSW

URL

http://code.google.com/p/apsw/

licence
zlib/libpng license (or any OSI approved license of your choice)
platforms
Windows, POSIX
Python versions
2.3 onwards, 3.1 onwards

Programming Model

APSW is a Python wrapper for the SQLite embedded relational database engine. In contrast to other wrappers such as pysqlite it focuses on being a minimal layer over SQLite attempting just to translate the complete SQLite API into Python. The documentation has a section on the differences between APSW and pysqlite.


Supported Python Applications

  • Thuban (GIS application)
  • Roundup (issue tracker)
  • PyPI (Python Package Index)
  • Trac (issue tracker, wiki, Subversion web frontend)
  • Cloud Wiki (wiki)
  • Supybot (IRC bot framework)
  • PyAddbook (Address Book)

Usage Notes

The following solution was difficult to discover with the available documentation (http://pysqlite.org/ was unavailable). If this page can be found by others searching for answers, it may save many hours of frustration.

Id of Most Recent Row

After creating a new row in a table that uses AUTOINCREMENT to create the PRIMARY KEY, one may wish to determine the value of the new row-id, for example if the value is need for a new row in a related table that will be inserted next. The answer is to use the lastrowid property of the cursor class as in newId=c.lastrowid  shown below in a demo context. Tested in Python2.5.1 with the sqlite3 module:

           import sqlite3 

# for py24 use from pysqlite2 import dbapi2 as sqlite

           con = sqlite3.connect('demo.db')
           con.execute("""CREATE TABLE tbl (
               id INTEGER PRIMARY KEY AUTOINCREMENT,
               grp INTEGER)""")
           c = con.cursor()
           c.execute("""INSERT INTO tbl (grp) VALUES (0);""")

           newId = c.lastrowid

           print "New rowid =", newId
           c.close()
           con.close()

The result is printed: New rowid = 1

SQLite (last edited 2012-01-30 07:26:58 by 50-0-67-239)

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