Question

我使用C ++和SQLite与CppSQLite包装器（http://www.codeproject.com/Articles/6343/CppSQLite-C-Wrapper-for-SQLite），我一直收到SQLITE_BUSY错误尝试关闭（）。

我知道它有时是因为没有调用finalize语句或诸如此类引起的，但是CppSQLite应该为我处理这个问题。只有一个线程用于此，所以它不应该是一个并发的东西。我正在使用大多数CppSQLite类，包括编译语句和缓冲区。

SQLManager::SQLManager()
{
    // ... other code

    m_pSqlDb = new CppSQLite3DB();

    const char* gszFile = ":memory:";

    m_pSqlDb->open(gszFile);

    // ... other code

}


SQLManager::~SQLManager() 
{
    if(m_pSqlDb != NULL)
    {   
        try
        {
            remove("C:\\sqldump.db");
            m_pSqlDb->loadOrSaveDb(m_pSqlDb->mpDB, "C:\\sqldump.db", 1);
            m_pSqlDb->close();
            delete m_pSqlDb;
        }
        catch(CppSQLite3Exception e)
        {
            ASSERT(false);
        }
    }
}

然后我使用以下代码（http://www.sqlite.org/backup.html）将表格从内存写入文件。

/*
** This function is used to load the contents of a database file on disk 
** into the "main" database of open database connection pInMemory, or
** to save the current contents of the database opened by pInMemory into
** a database file on disk. pInMemory is probably an in-memory database, 
** but this function will also work fine if it is not.
**
** Parameter zFilename points to a nul-terminated string containing the
** name of the database file on disk to load from or save to. If parameter
** isSave is non-zero, then the contents of the file zFilename are 
** overwritten with the contents of the database opened by pInMemory. If
** parameter isSave is zero, then the contents of the database opened by
** pInMemory are replaced by data loaded from the file zFilename.
**
** If the operation is successful, SQLITE_OK is returned. Otherwise, if
** an error occurs, an SQLite error code is returned.
*/
int loadOrSaveDb(sqlite3 *pInMemory, const char *zFilename, int isSave){
  int rc;                   /* Function return code */
  sqlite3 *pFile;           /* Database connection opened on zFilename */
  sqlite3_backup *pBackup;  /* Backup object used to copy data */
  sqlite3 *pTo;             /* Database to copy to (pFile or pInMemory) */
  sqlite3 *pFrom;           /* Database to copy from (pFile or pInMemory) */

  /* Open the database file identified by zFilename. Exit early if this fails
  ** for any reason. */
  rc = sqlite3_open(zFilename, &pFile);
  if( rc==SQLITE_OK ){

    /* If this is a 'load' operation (isSave==0), then data is copied
    ** from the database file just opened to database pInMemory. 
    ** Otherwise, if this is a 'save' operation (isSave==1), then data
    ** is copied from pInMemory to pFile.  Set the variables pFrom and
    ** pTo accordingly. */
    pFrom = (isSave ? pInMemory : pFile);
    pTo   = (isSave ? pFile     : pInMemory);

    /* Set up the backup procedure to copy from the "main" database of 
    ** connection pFile to the main database of connection pInMemory.
    ** If something goes wrong, pBackup will be set to NULL and an error
    ** code and  message left in connection pTo.
    **
    ** If the backup object is successfully created, call backup_step()
    ** to copy data from pFile to pInMemory. Then call backup_finish()
    ** to release resources associated with the pBackup object.  If an
    ** error occurred, then  an error code and message will be left in
    ** connection pTo. If no error occurred, then the error code belonging
    ** to pTo is set to SQLITE_OK.
    */
    pBackup = sqlite3_backup_init(pTo, "main", pFrom, "main");
    if( pBackup ){
      (void)sqlite3_backup_step(pBackup, -1);
      (void)sqlite3_backup_finish(pBackup);
    }
    rc = sqlite3_errcode(pTo);
  }

  /* Close the database connection opened on database file zFilename
  ** and return the result of this function. */
  (void)sqlite3_close(pFile);
  return rc;
}

我真的不确定为什么我会收到一个忙碌的错误，除非写出没有完成或保持锁定或其他什么。任何建议将不胜感激。谢谢！

编辑：

我认为它可能是我的编译语句，但我确保在所有这些语句上调用finalize（），并且编译语句的析构函数无论如何都调用finalize（）。仍然卡住:(

它似乎也没有与loadOrSaveDb（）函数有任何关系，也似乎与写入：memory：。

无关。

Answer 1

原来它是编译后的语句，但我仍然不确定原因。我拿出来然后工作正常。

SQLite SQLITE_BUSY [5]在命中析构函数并使用：memory时：

1 个答案: