New submission from Jim Carroll:
I reported this to the sqlite mailing list, and the comments I received
suggested the problem may by the python sqlite connector issue, so I'm opening
this as a bug report.
I understand that performing a SELECT and nested COMMIT on the same table is
not supported in sqlite, but I would have expected a COMMIT on a separate table
would not be a problem. Some test code in python however reveals that
performing the COMMIT disrupts the SELECT statement, and causes duplicate data
to be returned.
If this is not a supported operation, would you mind pointing me to the docs so
I can understand it better?
Example
#!/usr/bin/env python
import sqlite3 as sq
db = sq.connect(':memory:')
db.execute('CREATE TABLE tbl (col INTEGER)')
db.execute('CREATE TABLE tbl2 (col INTEGER)')
db.executemany('INSERT INTO tbl (col) VALUES (?)', [(0,), (1,), (2,)])
db.commit()
print('count=' + str(db.execute('SELECT count(*) FROM tbl').fetchone()[0]))
# Read and print the values just inserted into tbl
for col in db.execute('SELECT col FROM tbl'):
print(col)
db.execute('INSERT INTO tbl2 VALUES (?)', col)
db.commit()
print('count=' + str(db.execute('SELECT count(*) FROM tbl').fetchone()[0]))
The output we see is:
count=3
(0,)
(1,)
(0,)
(1,)
(2,)
count=3
The expected output was:
count=3
(0,)
(1,)
(2,)
count=3
Tested on Linux:
sqlite version 3.7.13
sqlite3 connector version 2.6.0
# uname -a
Linux hostname 3.16-0.bpo.3-amd64 #1 SMP Debian
3.16.5-1~bpo70+1 (2014-11-02) x86_64 GNU/Linux
Also tested on Windows with identical results
Sqlite version 3.6.21
Windows 7 Professional, 64-bit
----------
messages: 233178
nosy: jamercee
priority: normal
severity: normal
status: open
title: sqlite3 COMMIT nested in SELECT returns unexpected results
type: behavior
versions: Python 2.7
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Python tracker <[email protected]>
<http://bugs.python.org/issue23129>
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