收到錯誤java.lang.IllegalStateException：從行0山坳得到場插槽-1失敗

Question

助手類：

package com.deangrobler.myApp; 

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

import android.content.Context; 
import android.database.Cursor; 
import android.database.SQLException; 
import android.database.sqlite.*; 

public class DataBaseHelper extends SQLiteOpenHelper{ 

//The Android's default system path of your application database. 
private static String DB_PATH = "/data/data/com.deangrobler.chumperoo/databases/"; 
private static String DB_NAME = "ChumperooDB.db"; 
private SQLiteDatabase myDataBase; 

private final Context myContext; 

/** 
* Constructor 
* Takes and keeps a reference of the passed context in order to access to the application assets and resources. 
* @param context 
*/ 
public DataBaseHelper(Context context) { 

    super(context, DB_NAME, null, 1); 
    this.myContext = context; 
} 

/** 
* Creates a empty database on the system and rewrites it with your own database. 
* */ 
public void createDataBase() throws IOException{ 

    boolean dbExist = checkDataBase(); 

    if(dbExist){ 
     //do nothing - database already exist 
    }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(); 

     try { 

      copyDataBase(); 

     } catch (IOException e) { 

      throw new Error("Error copying database: " + e.getStackTrace()); 

     } 
    } 

} 

/** 
* Check if the database already exist to avoid re-copying the file each time you open the application. 
* @return true if it exists, false if it doesn't 
*/ 
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; 
} 

/** 
* Copies your database from your local assets-folder to the just created empty database in the 
* system folder, from where it can be accessed and handled. 
* This is done by transfering bytestream. 
* */ 
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_READWRITE); 

} 

@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) { 

} 

//Queries the database 
public Cursor queryDataBase(String table, String[] columns, String selection){ 

    return myDataBase.query(table, columns, selection, null, null, null, null); 

} 

} 

用我的Main.java像這樣：

DataBaseHelper myDbHelper = new DataBaseHelper(this); 

    try { 
     myDbHelper.createDataBase(); 
    } catch (IOException ioe) { 
     throw new Error("Unable to create database"); 
    } 

    try { 
     myDbHelper.openDataBase(); 
    }catch(SQLException sqle){ 
     throw sqle; 
    } 

    //Get cursor and print out data 
    Cursor returnedCur = myDbHelper.queryDataBase("Expenses", new String[]{"Name","Amount"}, null); 
    if (returnedCur.moveToFirst()){ 
     do{ 
      String data = returnedCur.getString(returnedCur.getColumnIndex("data")); 
      System.out.println("Returned Data: "+data); 

     }while(returnedCur.moveToNext()); 
    } 
    returnedCur.close(); 

最後我的整個日誌：

> 06-05 13:28:35.885: E/CursorWindow(733): Bad request for field slot 0,-1. numRows = 1, numColumns = 2 
06-05 13:28:35.885: D/AndroidRuntime(733): Shutting down VM 
06-05 13:28:35.885: W/dalvikvm(733): threadid=1: thread exiting with uncaught exception (group=0x40015560) 
06-05 13:28:35.904: E/AndroidRuntime(733): FATAL EXCEPTION: main 
06-05 13:28:35.904: E/AndroidRuntime(733): **java.lang.RuntimeException: Unable to start activity ComponentInfo{com.deangrobler.chumperoo/com.deangrobler.chumperoo.Main}: java.lang.IllegalStateException: get field slot from row 0 col -1 failed** 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1622) 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1638) 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:928) 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.os.Handler.dispatchMessage(Handler.java:99) 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.os.Looper.loop(Looper.java:123) 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.app.ActivityThread.main(ActivityThread.java:3647) 
06-05 13:28:35.904: E/AndroidRuntime(733): at java.lang.reflect.Method.invokeNative(Native Method) 
06-05 13:28:35.904: E/AndroidRuntime(733): at java.lang.reflect.Method.invoke(Method.java:507) 
06-05 13:28:35.904: E/AndroidRuntime(733): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 
06-05 13:28:35.904: E/AndroidRuntime(733): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
06-05 13:28:35.904: E/AndroidRuntime(733): at dalvik.system.NativeStart.main(Native Method) 
06-05 13:28:35.904: E/AndroidRuntime(733): Caused by: java.lang.IllegalStateException: get field slot from row 0 col -1 failed 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.database.CursorWindow.getString_native(Native Method) 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.database.CursorWindow.getString(CursorWindow.java:329) 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:49) 
06-05 13:28:35.904: E/AndroidRuntime(733): at com.deangrobler.chumperoo.Main.onCreate(Main.java:55) 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
06-05 13:28:35.904: E/AndroidRuntime(733): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1586) 
06-05 13:28:35.904: E/AndroidRuntime(733): ... 11 more 
06-05 13:28:53.264: I/Process(733): Sending signal. PID: 733 SIG: 9 

不知道爲什麼發生這種情況，我一直在使用Google，現在半天，並沒有什麼幫助我整理了這一點:-(

Answer 1

new String[]{"Name","Amount"} 

你所要求的「數據」領域，但我不能找到任何字段名稱「數據」在你的分貝。 你可以試試

String name = returnedCur.getString(returnedCur.getColumnIndex("Name"));