Sqlite python sqlite3.OperationalError:数据库被锁定

Question

我写了以下代码,显示sqlite3.OperationalError: database is locked错误.任何帮助调试将非常感激.

基本上我试图将数据从table1复制到table2,并根据某些其他应用程序发生在table1上的更改将数据插入到table2中.

看起来我错过了一些部分.

import sqlite3

conn = sqlite3.connect("/home/sid/.Skype/testmasterut/main.db")
cursor = conn.cursor()

createLogTableSql = """create table IF NOT EXISTS sid_log as select id as "s_id",author as "s_author",timestamp as "s_timestamp",edited_by as "s_editedby",edited_timestamp as "s_edited_timestamp",body_xml as "s_body_xml" from Messages"""

cursor.execute(createLogTableSql)
conn.commit()
print "Table to save the old messages has been created"

selectLog = """ select * from sid_log """
original_table = cursor.execute(selectLog)

cursor2 = conn.cursor()
cursor3 = conn.cursor()
cursor4 = conn.cursor()

InsertTest = """ insert or ignore into sid_log (s_id,s_author,s_timestamp,s_editedby,s_edited_timestamp,s_body_xml)
select id,author,timestamp,edited_by,edited_timestamp,body_xml from Messages where id not in (select s_id from sid_log where s_id = id) and edited_by is NULL and edited_timestamp is NULL
"""

EditedTest = """ select * from Messages where id in (select s_id from sid_log where s_id = id) and edited_by is not NULL and edited_timestamp is not NULL"""
conn.close()

while True:
    conn2 = sqlite3.connect("/home/sid/.Skype/testmasterut/main.db",timeout=3)
    conn2.execute(InsertTest)

    print "Total number of rows changed:", conn.total_changes
    EditedTest2 = """ select * from Messages where id in (select s_id from sid_log where s_id = id) and edited_by is not NULL and edited_timestamp is not NULL"""
    edited_list = conn2.execute(EditedTest2)
    conn2.commit()
    conn2.close()
    # for row in edited_list:
    #   queryString = "SELECT * FROM sid_log WHERE s_id IN (%s)" % str(row[0])
    #   original_message = conn.execute(queryString)
    #   for org_row in original_message:
    #       print "Message edited from", org_row[5], "to", row[5]

编辑 下面是追溯

Traceback (most recent call last):
  File "try2.py", line 28, in <module>
    conn2.execute(InsertTest)
sqlite3.OperationalError: database is locked

Answer 1

我不确定这是否会对任何人有所帮助,但我找到了解决我自己的锁定数据库问题的方法.

我使用PyCharm,发现我正在处理的脚本的几个实例都在运行.这通常是由于我正在测试的代码中的错误,但它保持活动状态(因此与db的连接仍处于活动状态).关闭那些(停止所有过程)并再试一次 - 它每次都适合我!

如果有人知道一段时间后让它超时的方法,请评论此解决方案.我试过cur.execute("PRAGMA busy_timeout = 30000")(从另一个线程中找到一个类似的问题)但它似乎没有做任何事情.

Answer 2

“数据库已锁定”意味着其他某个连接具有活动连接。

使用PRAGMA busy_timeout等待其他事务完成一段时间：

conn.execute("PRAGMA busy_timeout = 30000")   # 30 s

但是，如果其他应用程序故意保持打开的事务以保持数据库锁定，则您无能为力。