复制数据库时出错

Question

使用助手复制数据库没有问题。但是由于今天重新格式化了我的电脑并安装了 Eclipse，所以我不能再复制数据库了。可能是模拟器的sd卡导致问题。原木猫是这样说的。

07-23 14:23:48.875：E/AndroidRuntime(237)：未捕获的处理程序：线程主因未捕获的异常而退出
07-23 14:23:48.885: E/AndroidRuntime(237): java.lang.RuntimeException: 无法启动活动 ComponentInfo{com.frux.kfcmobile/com.frux.kfcmobile.KFCmobileActivity}: android.database.sqlite.SQLiteException : 没有这样的表: first: , 编译时: SELECT *from first
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.app.ActivityThread.access$2200(ActivityThread.java:119)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.os.Handler.dispatchMessage(Handler.java:99)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.os.Looper.loop(Looper.java:123)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.app.ActivityThread.main(ActivityThread.java:4363)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 java.lang.reflect.Method.invokeNative(Native Method)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 java.lang.reflect.Method.invoke(Method.java:521)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
07-23 14:23:48.885: E/AndroidRuntime(237): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
07-23 14:23:48.885: E/AndroidRuntime(237): at dalvik.system.NativeStart.main(Native Method)
07-23 14:23:48.885: E/AndroidRuntime(237): 引起: android.database.sqlite.SQLiteException: 没有这样的表: first: , 编译时: SELECT *from first
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.database.sqlite.SQLiteProgram.native_compile(Native Method)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.database.sqlite.SQLiteProgram.compile(SQLiteProgram.java:110)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.database.sqlite.SQLiteProgram.(SQLiteProgram.java:59)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.database.sqlite.SQLiteQuery.(SQLiteQuery.java:49)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:49)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1220)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1193)
07-23 14:23:48.885: E/AndroidRuntime(237): at com.frux.kfcmobile.KFCmobileActivity.onCreate(KFCmobileActivity.java:42)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-23 14:23:48.885: E/AndroidRuntime(237): 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)

这是我的 DBHelper

公共类 DatabaseHelper 扩展 SQLiteOpenHelper{

private static String DB_PATH = "/data/data/com.frux.kfcmobile/databases/";
private static String DB_NAME = "database";
private SQLiteDatabase myDataBase; 
private final Context myContext;
private static final int DATABASE_VERSION = 1;


public DatabaseHelper(Context context) {
    // TODO Auto-generated constructor stub
    super(context, DB_NAME, null, DATABASE_VERSION);
    this.myContext = context;


}
 public void createDataBase() throws IOException{

        boolean dbExist = checkDataBase();

        if(dbExist){
            //do nothing - database already exist
            this.getWritableDatabase();
            this.close();
        }else{

            //By calling this method and empty database will be created into the default system path
               //of your application so we are gonna be able to overwrite that database with our database.
            this.getReadableDatabase();
            this.close();
            try {

                copyDataBase();

            } catch (IOException e) {

            //throw new Error("Error copying database message");

            }
        }

    }


 private boolean checkDataBase(){

        SQLiteDatabase checkDB = null;

        try{
            String myPath = DB_PATH + DB_NAME;
            checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);

        }catch(SQLiteException e){

            //database does't exist yet.

        }

        if(checkDB != null){

            checkDB.close();

        }

        return checkDB != null ? true : false;
    }



 private void copyDataBase() throws IOException{

        //Open your local db as the input stream
        InputStream myInput = myContext.getAssets().open(DB_NAME);

        // Path to the just created empty db
        String outFileName = DB_PATH + DB_NAME;

        //Open the empty db as the output stream
        OutputStream myOutput = new FileOutputStream(outFileName);

        //transfer bytes from the inputfile to the outputfile
        byte[] buffer = new byte[1024];
        int length;
        while ((length = myInput.read(buffer))>0){
            myOutput.write(buffer, 0, length);
        }

        //Close the streams
        myOutput.flush();
        myOutput.close();
        myInput.close();

    }



 public void openDataBase() throws SQLException{

        //Open the database
        String myPath = DB_PATH + DB_NAME;
        myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);

    }

    @Override
    public synchronized void close() {

            if(myDataBase != null)
                myDataBase.close();

            super.close();

    }

    @Override
    public void onCreate(SQLiteDatabase db) {


    }





    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {


    }

}

Answer 1

关注下一行，别忘了放 .sqlite 扩展名：

private static String DB_NAME = "wfbos.sqlite";

它对我有用。

Answer 2

你可以使用我的 DbHelper..它是从资产文件夹复制的数据库...

package com.Blog;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;


public class DBAdapter extends SQLiteOpenHelper 
{
    private static String DB_NAME = "wfbos.sqlite";
    private String DB_PATH  = "";

    private static DBAdapter adb;
    private SQLiteDatabase db;
    private Context myContext;

    /*public DBAdapter(Context context, String name, CursorFactory factory,int version) 
    {
        super(context, DB_NAME, factory, 1);

        this.myContext = context;
        DB_PATH = "/data/data/"+myContext.getPackageName()+"/databases/";

    }*/
    public DBAdapter(Context context)
    {   
        super(context, DB_NAME, null,1);

        this.myContext = context;
        DB_PATH = "/data/data/"+myContext.getPackageName()+"/databases/";
    }


    public static synchronized DBAdapter getAdapterInstance(Context context)
    {
        if(adb == null)
        {
          adb = new DBAdapter(context);
        }

        return adb;

    }


    public void createdatabase()
    {
        boolean dbExist = checkDataBase();
        if(dbExist)
        {


        }
        else
        {
            this.getReadableDatabase();
            try 
            {
                copyDataBase();
            } 
            catch (IOException e)
            {
                Log.v("log",e.toString());
                throw new Error("Error copying database");
            }

        }
    }

    private void copyDataBase() throws IOException
    {

        // Open your local db as the input stream
        InputStream myInput = myContext.getAssets().open(DB_NAME);

        // Path to the just created empty db
        String outFileName = DB_PATH + DB_NAME;

        // Open the empty db as the output stream
        OutputStream myOutput = new FileOutputStream(outFileName);

        // transfer bytes from the inputfile to the outputfile
        byte[] buffer = new byte[1024];
        int length;
        while ((length = myInput.read(buffer)) > 0) 
        {
            myOutput.write(buffer, 0, length);
        }
        Log.v("log", "copy finish");
        // Close the streams
        myOutput.flush();
        myOutput.close();
        myInput.close();
    }

     private boolean checkDataBase() 
     {
         SQLiteDatabase checkDB = null;
         try 
         {
             String myPath = DB_PATH + DB_NAME;
             checkDB = SQLiteDatabase.openDatabase(myPath, null,
                     SQLiteDatabase.OPEN_READONLY);
         }
         catch (SQLiteException e) 
         {
         }
         if (checkDB != null)
         {
             checkDB.close();
         }
         return checkDB != null ? true : false;
     }


     public SQLiteDatabase openDataBase() throws SQLException
     {
         // Open the database
         String myPath = DB_PATH + DB_NAME;

         db= SQLiteDatabase.openDatabase(myPath, null,
                 SQLiteDatabase.OPEN_READWRITE);

         return db;
     }



    @Override
    public void onCreate(SQLiteDatabase db)
    {
        // TODO Auto-generated method stub

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) 
    {
        // TODO Auto-generated method stub

    }
    @Override
    public synchronized void close() {

            if(db != null)
                db.close();

            super.close();

    }
}

Answer 3

您以某种方式弄乱了DBHelper 中的onCreate 方法。这没有发生，因为您之前总是创建数据库。现在您必须在新设备（您的案例新模拟器）上进行全新安装，如果失败，因为您的 Create Table 查询可能是错误的并且表没有正确创建。

所以检查一下，我很确定这就是你的问题。

编辑：

我还认为您在* 和first 之间缺少一个空格，例如：

SELECT * from first