有些函数，比如INDEX'ing，可能会花费很长时间——而且在运行时它会锁定整个数据库。在这种情况下，它甚至可能不使用日志文件!

因此，最好/唯一的方法来检查您的数据库是否被锁定，因为一个进程正在积极地写入它(因此你应该让它独自呆着，直到它完成它的操作)是md5(或md5sum在某些系统)文件两次。 如果你得到一个不同的校验和，数据库正在被写入，你真的真的真的不想杀死这个进程，因为如果你这样做，你很容易得到一个损坏的表/数据库。

我要重申一下，因为这很重要——解决方案不是找到锁程序并杀死它——而是找出数据库是否有一个很好的写锁，然后从那里开始。有时候正确的解决方法就是喝杯咖啡休息一下。

The only way to create this locked-but-not-being-written-to situation is if your program runs BEGIN EXCLUSIVE, because it wanted to do some table alterations or something, then for whatever reason never sends an END afterwards, and the process never terminates. All three conditions being met is highly unlikely in any properly-written code, and as such 99 times out of 100 when someone wants to kill -9 their locking process, the locking process is actually locking your database for a good reason. Programmers don't typically add the BEGIN EXCLUSIVE condition unless they really need to, because it prevents concurrency and increases user complaints. SQLite itself only adds it when it really needs to (like when indexing).

Finally, the 'locked' status does not exist INSIDE the file as several answers have stated - it resides in the Operating System's kernel. The process which ran BEGIN EXCLUSIVE has requested from the OS a lock be placed on the file. Even if your exclusive process has crashed, your OS will be able to figure out if it should maintain the file lock or not!! It is not possible to end up with a database which is locked but no process is actively locking it!! When it comes to seeing which process is locking the file, it's typically better to use lsof rather than fuser (this is a good demonstration of why: https://unix.stackexchange.com/questions/94316/fuser-vs-lsof-to-check-files-in-use). Alternatively if you have DTrace (OSX) you can use iosnoop on the file.

我只是犯了同样的错误。 5分钟后，我发现我没有关闭一个shell巫婆正在使用db。 请关闭它，再试一次;)

根据我的经验，此错误是由以下原因引起的:您打开了多个连接。

例如:

1个或多个sqlitebrowser (GUI) 一个或多个电子线 rails线程

我不确定SQLITE3如何处理多线程/请求的细节，但当我关闭sqlitebrowser和电子线程时，rails运行良好，不会再阻塞了。

在我的例子中，我也得到了这个错误。

我已经检查了其他进程，可能是锁定数据库的原因，如(SQLite管理器，连接到我的数据库的其他程序)。但是没有其他程序连接到它，它只是同一个应用程序中保持连接的另一个活动SQLConnection。

在建立新的SQLConnection和新命令之前，尝试检查您以前的活动SQLConnection，它可能仍然被连接(首先断开它)。

您可以尝试:.timeout 100来设置超时时间。 我不知道在命令行中发生了什么，但在c# .Net中，当我这样做:“UPDATE table-name SET column-name = value;”我得到数据库被锁定，但这个“UPDATE table-name SET column-name = value”它很好。

看起来，当您添加;，sqlite将寻找进一步的命令。

删除-journal文件听起来是个糟糕的主意。它允许sqlite在崩溃后将数据库回滚到一致的状态。如果在数据库处于不一致状态时删除它，则会留下一个损坏的数据库。引用sqlite站点的一个页面:

If a crash or power loss does occur and a hot journal is left on the disk, it is essential that the original database file and the hot journal remain on disk with their original names until the database file is opened by another SQLite process and rolled back. [...] We suspect that a common failure mode for SQLite recovery happens like this: A power failure occurs. After power is restored, a well-meaning user or system administrator begins looking around on the disk for damage. They see their database file named "important.data". This file is perhaps familiar to them. But after the crash, there is also a hot journal named "important.data-journal". The user then deletes the hot journal, thinking that they are helping to cleanup the system. We know of no way to prevent this other than user education.

The rollback is supposed to happen automatically the next time the database is opened, but it will fail if the process can't lock the database. As others have said, one possible reason for this is that another process currently has it open. Another possibility is a stale NFS lock, if the database is on an NFS volume. In that case, a workaround is to replace the database file with a fresh copy that isn't locked on the NFS server (mv database.db original.db; cp original.db database.db). Note that the sqlite FAQ recommends caution regarding concurrent access to databases on NFS volumes, because of buggy implementations of NFS file locking.

我无法解释为什么删除一个-journal文件会让你锁定一个数据库，而你以前不能。这是可复制的吗?

顺便说一下，-journal文件的存在并不一定意味着发生了崩溃或有要回滚的更改。Sqlite有几种不同的日志模式，在PERSIST或TRUNCATE模式下，它始终保留-journal文件，并更改内容以指示是否有要回滚的部分事务。