473,713 Members | 2,743 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

Strange sqlite3 library behavior

Now I am now developing a program that base on sqlite3 in python.
But there is a strange problem.
That is, all data I insert into sqlite database do not goes into file
in disk.
It is really strange....
Why do these data just keep in memory and discarded?

All things that really store in file is the table.
If I create a table, it would appears in the sqlite file.

This is the example :

import sqlite3

createSyntax = """CREATE TABLE IF NOT EXISTS category(
id INTEGER NOT NULL PRIMARY KEY
)"""

createSyntax2 = """CREATE TABLE IF NOT EXISTS category2(
id INTEGER NOT NULL PRIMARY KEY
)"""

insertSyntax = """INSERT INTO category VALUES (1234)"""

db = sqlite3.connect ('test.db')
cur = db.cursor()
cur.execute(cre ateSyntax)
cur.execute(ins ertSyntax)
# only by doing so can let inserted data store in file
cur.execute(cre ateSyntax2)
cur.execute('se lect * from category')
print cur.fetchall()

db.close()

raw_input()
After I tried some way. I found that create table force data goes into
file. Otherwise all data would just keep in memory and discarded with
the program's ending.
Why sqlite3 just keep inserted data in memory? And how to force
inserted data into file?

Thanks.

Victor Lin.
Feb 2 '08 #1
2 1715
Victor Lin schreef:
Now I am now developing a program that base on sqlite3 in python.
But there is a strange problem.
That is, all data I insert into sqlite database do not goes into file
in disk.
It is really strange....
Why do these data just keep in memory and discarded?
sqlite3 works according to PEP 249, which means among other things that
transactions are by default not auto-committed.

There are two possible solutions:
- manually commit the transaction when it's finished with db.commit()
(perhaps the cursor object also has a commit() method; I'm not sure
about that)
- enable auto-commit.

For more info, see the sqlite3 docs (especially the section on
controlling transactions:
http://docs.python.org/lib/sqlite3-C...nsactions.html) and
PEP 249 (http://www.python.org/dev/peps/pep-0249/)

--
The saddest aspect of life right now is that science gathers knowledge
faster than society gathers wisdom.
-- Isaac Asimov

Roel Schroeven
Feb 2 '08 #2
2008/2/2, Roel Schroeven <rs************ ****@fastmail.f m>:
Victor Lin schreef:
Now I am now developing a program that base on sqlite3 in python.
But there is a strange problem.
That is, all data I insert into sqlite database do not goes into file
in disk.
It is really strange....
Why do these data just keep in memory and discarded?


sqlite3 works according to PEP 249, which means among other things that
transactions are by default not auto-committed.

There are two possible solutions:
- manually commit the transaction when it's finished with db.commit()
(perhaps the cursor object also has a commit() method; I'm not sure
about that)
- enable auto-commit.
While these solutions are correct I wouldn't suggest enabling
auto-commit, you will have serious performance issues.
>
For more info, see the sqlite3 docs (especially the section on
controlling transactions:
http://docs.python.org/lib/sqlite3-C...nsactions.html) and
PEP 249 (http://www.python.org/dev/peps/pep-0249/)

--
The saddest aspect of life right now is that science gathers knowledge
faster than society gathers wisdom.
-- Isaac Asimov
Roel Schroeven

--
http://mail.python.org/mailman/listinfo/python-list

--
-- Guilherme H. Polo Goncalves
Feb 2 '08 #3

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

2
2192
by: lolmcbride | last post by:
Hi, is it possible to pass args through the api which are the same as the args you can use on the sqlite3 command line? What I'm talking about is the .mode or .output commands which you can enter via the sqlite3 cli so I can dynamically change were the output goes. Ta
2
3622
by: Harold Shore | last post by:
From the release notes I read that "If you're compiling the Python source yourself, note that the source tree doesn't include the SQLite code, only the wrapper module. You'll need to have the SQLite libraries and headers installed before compiling Python, and the build process will compile the module when the necessary headers are available." I do have SQLite3 installed on my system, but after doing a
66
7066
by: mensanator | last post by:
Probably just me. I've only been using Access and SQL Server for 12 years, so I'm sure my opinions don't count for anything. I was, nevertheless, looking forward to Sqlite3. And now that gmpy has been upgraded, I can go ahead and install Python 2.5. So I open the manual to Section 13.13 where I find the first example of how to use Sqlite3:
3
1905
by: cjl | last post by:
P: I am using python 2.5.1 on windows. I have the following code: conn = sqlite3.connect('.\optiondata') c = conn.cursor() try: c.execute('''create table options (ssymbol text, strike real, osymbol text, bid real, mpp real, upp real)''') except sqlite3.OperationalError:
4
8920
by: Simon | last post by:
I installed the source code on unix for python 2.5.1. The install went mainly okay, except for some failures regarding: _ssl, _hashlib, _curses, _curses_panel. No errors regarding sqlite3. However, when I start python and do an import sqlite3 I get: /ptmp/bin/python Python 2.5.1 (r251:54863, May 29 2007, 05:19:30) on sunos5
1
3100
by: jeff_d_harper | last post by:
I've run into a problem with text encoding in the Sqlite3 module. I think it may be a bug. By default sqlite3 converts strings in the database from UTF-8 to unicode. This conversion can be controlled by changing the connection's text_factory. I have a database that stores strings in 8-bit ISO-8859. So, I set the text_factory to do no conversion. In my database I use user defined functions. I noticed that even when I set...
15
14771
by: Kurda Yon | last post by:
Hi, I try to "build" and "install" pysqlite? After I type "python setup.py build" I get a lot of error messages? The first error is "src/ connection.h:33:21: error: sqlite3.h: No such file or directory". So, I assume that the absence of the "sqlite3.h" is the origin of the problem. I found on the web, that this file should be either in "/usr/local/ include" or in "/usr/local/lib". I check this directories and I really
12
1589
by: Gilles Ganault | last post by:
Hello I'm getting some unwanted result when SELECTing data from an SQLite database: ====== sql = 'SELECT id FROM master' rows=list(cursor.execute(sql)) for id in rows: sql = 'SELECT COUNT(code) FROM companies WHERE code="%s"' % id
0
355
by: =?ISO-8859-1?Q?Gerhard_H=E4ring?= | last post by:
Charles V. wrote: Yes. Both may be standard compliant, but if you're depending on implementation details, you may still get different behaviour. I'm pretty sure that MySQLdb always fetches the entire resultset from the server. The sqlite3 module uses what would have been called "server-side cursors" in real databases, i. e. it only fetches rows on
0
8795
marktang
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look ! Part I. Meaning of...
0
9306
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed. This is as boiled down as I can make it. Here is my compilation command: g++-12 -std=c++20 -Wnarrowing bit_field.cpp Here is the code in...
1
9068
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
0
9009
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
0
7942
agi2029
by: agi2029 | last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own.... Now, this would greatly impact the work of software developers. The idea...
0
5943
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one. At the time of converting from word file to html my equations which are in the word document file was convert into image. Globals.ThisAddIn.Application.ActiveDocument.Select();...
0
4715
by: adsilva | last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
1
3155
by: 6302768590 | last post by:
Hai team i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
3
2103
bsmnconsultancy
by: bsmnconsultancy | last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.