在python sqlite3中使用保存点

Question

我正在尝试将保存点与python 2.6中内置的sqlite3模块一起使用.每次我尝试释放或回滚保存点时,我总是收到一个OperationalError: no such savepoint.我错过了什么？

python version: 2.6.4 (r264:75821M, Oct 27 2009, 19:48:32) 
[GCC 4.0.1 (Apple Inc. build 5493)]
PySQLite version: 2.4.1
sqlite3 version: 3.6.11

Traceback (most recent call last):
  File "spDemo.py", line 21, in <module>
    conn.execute("release savepoint spTest;")
sqlite3.OperationalError: no such savepoint: spTest

从这段代码:

import sys
import sqlite3

print 'python version:', sys.version
print 'PySQLite version:', sqlite3.version
print 'sqlite3 version:', sqlite3.sqlite_version
print

conn = sqlite3.connect('db_spDemo.db')
conn.isolation_level = "DEFERRED"

with conn:
    conn.execute("create table example (A, B);")

with conn:
    conn.execute("insert into example values (?, ?);", (0,200))

    conn.execute("savepoint spTest;")
    conn.execute("insert into example values (?, ?);", (1,201))
    conn.execute("insert into example values (?, ?);", (2,202))
    conn.execute("release savepoint spTest;")

    conn.execute("insert into example values (?, ?);", (5,205))

Answer 1

这似乎是 sqlite3 模块在该隔离级别下的行为方式造成的。

这有效，注意两个变化：

import sys
import sqlite3

print 'python version:', sys.version
print 'PySQLite version:', sqlite3.version
print 'sqlite3 version:', sqlite3.sqlite_version
print

conn = sqlite3.connect('shane.sqlite')
conn.isolation_level = None  # CHANGED

with conn:
    conn.execute("create table example (A, B);")

with conn:
    conn.execute("insert into example values (?, ?);", (0,200))

    conn.execute("savepoint spTest;")
    conn.execute("insert into example values (?, ?);", (1,201))
    conn.execute("insert into example values (?, ?);", (2,202))
    conn.execute("rollback to savepoint spTest;")  # CHANGED

    conn.execute("insert into example values (?, ?);", (5,205))

输出：

$ python shane-sqlite3.py && sqlite3 shane.sqlite '从示例中选择 *;'
python 版本：2.6.2（release26-maint，2009 年 4 月 19 日，01:56:41）
[海湾合作委员会4.3.3]
PySQLite 版本：2.4.1
sqlite3版本：3.6.10

0|200
5|205

这是一个令人不满意的答案，我没有在 sqlite3 模块文档中看到任何相关内容（我也没有尝试查看源代码）。但我希望它能帮助你找到正确的方向。