使用后续查询时无法打开数据库文件错误 [英] Unable to open database file error on using subsequent queries

问题描述

我有以下代码，第一个游标对象工作正常，但当我做另一个查询并将其分配给flightCursor，它给出错误。

  Cursor cursor = database.query（CityAndAirportsTable.notificationsTable，new String [] {CityAndAirportsTable.notifyFlightId}，
 null，null，null，null，Id DESC）; 
 cursor.moveToFirst（）; 
 while（！cursor.isAfterLast（））{
 String id = String.valueOf（cursor.getInt（0））; 
 Cursor flightCursor = database.query（CityAndAirportsTable.flightTable，new String [] {CityAndAirportsTable.fromDestinationCode，
 CityAndAirportsTable.toDestinationCode，CityAndAirportsTable.currentPrice}，CityAndAirportsTable.flightId +=+ id，
 null，null，null，null）; 
} 
  

这里在flightCursor = database.query，我得到错误。 p>

日志

  03-27 23：49：09.628：E / SQLiteLog （2296）：（14）无法在[9491ba7d73]的行30046打开文件
 03-27 23：49：09.628：E / SQLiteLog（2296）：（14）os_unix.c：30046： （/data/data/com.flightapp.myapp/databases/Application_DB-journal） -  
 03-27 23：49：09.628：E / SQLiteLog（2296）：（14）无法打开文件在第30046行[ 9491ba7d73] 
 03-27 23：49：09.628：E / SQLiteLog（2296）：（14）os_unix.c：30046：（24）open（/data/data/com.flightapp.myapp/databases/Application_DB -journal） -  
 03-27 23：49：09.628：E / SQLiteLog（2296）：（14）语句在11处中止：[SELECT FROM_Destination_Code，To_Destination_Code，Current_Price FROM Flights WHERE Id = 2]无法打开数据库文件
 03-27 23：49：09.629：E / SQLiteQuery（2296）：异常：无法打开数据库文件（代码14）。查询：SELECT From_Destination_Code，To_Destination_Code，Current_Price FROM Flights WHERE Id = 2 
  

但在我的情况下，第一个查询工作，但第二个失败。

解决方案

完成后关闭光标！我想你只有太多的游标对象打开了

  Cursor cursor = database.query（CityAndAirportsTable.notificationsTable，new String [ ] {CityAndAirportsTable.notifyFlightId}，
 null，null，null，null，Id DESC）; 
 cursor.moveToFirst（）; 
 while（！cursor.isAfterLast（））{
 String id = String.valueOf（cursor.getInt（0））; 
 Cursor flightCursor = database.query（
 CityAndAirportsTable.flightTable，
 new String [] {CityAndAirportsTable.fromDestinationCode，
 CityAndAirportsTable.toDestinationCode，
 CityAndAirportsTable.currentPrice}，
 CityAndAirportsTable.flightId +=+ id，
 null，null，null，null）; 
 
 / *在这里关闭光标！ * / 
 flightCursor.close（）; 
 / * ---------------------- * / 
} 
  

希望这可以修复您的问题

I have the following code, the first cursor object works fine, but when i do another query and assign it to the flightCursor, it gives the error.

Cursor cursor = database.query( CityAndAirportsTable.notificationsTable, new String[] { CityAndAirportsTable.notifyFlightId },
                null, null, null, null, "Id DESC" );
        cursor.moveToFirst();
        while( !cursor.isAfterLast() ){
            String id = String.valueOf( cursor.getInt( 0 ) );
            Cursor flightCursor = database.query( CityAndAirportsTable.flightTable, new String[] { CityAndAirportsTable.fromDestinationCode,
            CityAndAirportsTable.toDestinationCode, CityAndAirportsTable.currentPrice }, CityAndAirportsTable.flightId + "=" + id,
                    null, null, null, null );
}

Here in the flightCursor = database.query, i get the error.

Logs

03-27 23:49:09.628: E/SQLiteLog(2296): (14) cannot open file at line 30046 of [9491ba7d73]
03-27 23:49:09.628: E/SQLiteLog(2296): (14) os_unix.c:30046: (24) open(/data/data/com.flightapp.myapp/databases/Application_DB-journal) - 
03-27 23:49:09.628: E/SQLiteLog(2296): (14) cannot open file at line 30046 of [9491ba7d73]
03-27 23:49:09.628: E/SQLiteLog(2296): (14) os_unix.c:30046: (24) open(/data/data/com.flightapp.myapp/databases/Application_DB-journal) - 
03-27 23:49:09.628: E/SQLiteLog(2296): (14) statement aborts at 11: [SELECT From_Destination_Code, To_Destination_Code, Current_Price FROM Flights WHERE Id=2] unable to open database file
03-27 23:49:09.629: E/SQLiteQuery(2296): exception: unable to open database file (code 14); query: SELECT From_Destination_Code, To_Destination_Code, Current_Price FROM Flights WHERE Id=2

There are similar question on stackoverflow, but in my case the first query works but the second one fails.

解决方案

Close your cursor when you're done with it! I think you've just got too many cursor objects open

Cursor cursor = database.query( CityAndAirportsTable.notificationsTable, new String[] { CityAndAirportsTable.notifyFlightId },
                null, null, null, null, "Id DESC" );
cursor.moveToFirst();
while( !cursor.isAfterLast() ){
  String id = String.valueOf( cursor.getInt( 0 ) );
  Cursor flightCursor = database.query(
    CityAndAirportsTable.flightTable,
    new String[] { CityAndAirportsTable.fromDestinationCode,
      CityAndAirportsTable.toDestinationCode,
      CityAndAirportsTable.currentPrice },
    CityAndAirportsTable.flightId + "=" + id,
    null, null, null, null );

  /* Close the cursor here! */
  flightCursor.close();
  /* ---------------------- */
}

Hopefully this fixes your issue

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