錯誤：java.lang.IllegalStateException：從行0第2欄第拿到場插槽失敗的Android

Question

這是我MySqlLiteHelper：

public class MySQLiteHelper extends SQLiteOpenHelper { 

    public static final String TABLE_CMBS = "cbs"; 
    public static final String CMB_ID = "_id"; 
    public static final String COLUMN_CMB = "cmb"; 
    public static final String COLUMN_INFO = "cinfo"; 
    public static final String COLUMN_URL = "imageurl"; 


    private static final String DATABASE_NAME = "cmbsdr.db"; 
    private static final int DATABASE_VERSION = 1; 

    // Database creation sql statement 

    private static final String DATABASE_CREATE = 
     "create table "+ TABLE_CMBS +" (_id integer primary key autoincrement, " 
     + "cmb text, cbinfo text," 
     + "imageurl text);"; 


    public MySQLiteHelper(Context context) { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase database) { 
     database.execSQL(DATABASE_CREATE); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     Log.w(MySQLiteHelper.class.getName(), 
       "Upgrading database from version " + oldVersion + " to " 
         + newVersion + ", which will destroy all old data"); 
     db.execSQL("DROP TABLE IF EXISTS " + TABLE_CMBS); 
     onCreate(db); 
    } 

} 

    This is my Comments class: 



public class Comment { 
    private long id; 
    private String cmb; 
    private String cinfo; 
    private String imageurl; 

    public long getId() { 
     return id; 
    } 

    public void setId(long id) { 
     this.id = id; 
    } 

    public String getCmb() { 
     return cmb; 
    } 

    public void setCmb(String cmb) { 
     this.cmb = cmb; 
    } 
    public String getCInfo(){ 
      return cinfo; 
    } 
    public void setCInfo(String cinfo){ 
      this.cinfo = cinfo; 
    } 
    public void setImageUrl(String imageurl){ 
      this.imageurl = imageurl; 
    } 
    public String getImageUrl(){ 
      return imageurl; 
    } 



} 

這是我CommentsDataSource類：

public class CommentsDataSource { 

    // Database fields 
    private SQLiteDatabase database; 
    private MySQLiteHelper dbHelper; 
    private String[] allColumns = { MySQLiteHelper.CMB_ID, 
      MySQLiteHelper.COLUMN_CMB }; 

    public CommentsDataSource(Context context) { 
     dbHelper = new MySQLiteHelper(context); 
    } 

    public void open() throws SQLException { 
     database = dbHelper.getWritableDatabase(); 
    } 

    public void close() { 
     dbHelper.close(); 
    } 

    public Comment createComment(String cmb, String cinfo, String imageurl) { 
     ContentValues values = new ContentValues(); 
     values.put(MySQLiteHelper.COLUMN_CMB, cmb); 
     values.put(MySQLiteHelper.COLUMN_INFO, cinfo); 
     values.put(MySQLiteHelper.COLUMN_URL, imageurl); 

     long insertId = database.insert(MySQLiteHelper.TABLE_CMBS, null, 
       values); 
     Cursor cursor = database.query(MySQLiteHelper.TABLE_CMBS, 
       allColumns, MySQLiteHelper.CMB_ID + " = " + insertId, null, 
       null, null, null); 
     cursor.moveToFirst(); 
     Comment newComment = cursorToComment(cursor); 
     cursor.close(); 
     return newComment; 
    } 

    public void deleteComment(Comment comment) { 
     long id = comment.getId(); 
     System.out.println("Comment deleted with id: " + id); 
     database.delete(MySQLiteHelper.TABLE_CMBS, MySQLiteHelper.CMB_ID 
       + " = " + id, null); 
    } 

    public List<Comment> getAllComments() { 
     List<Comment> comments = new ArrayList<Comment>(); 

     Cursor cursor = database.query(MySQLiteHelper.TABLE_CMB, 
       allColumns, null, null, null, null,null); 

     cursor.moveToFirst(); 
     while (!cursor.isAfterLast()) { 
      Comment comment = cursorToComment(cursor); 
      comments.add(comment); 

      cursor.moveToNext(); 
     } 
     // Make sure to close the cursor 
     cursor.close(); 
     return comments; 
    } 

    private Comment cursorToComment(Cursor cursor) { 
     Comment comment = new Comment(); 
     comment.setId(cursor.getLong(0)); 
     comment.setCmb(cursor.getString(1)); 
     comment.setCInfo(cursor.getString(2)); 
     comment.setImageUrl(cursor.getString(3)); 
     return comment; 
    } 
} 

我得到的錯誤：

05-16 15:07:25.273: E/AndroidRuntime(26017): Caused by: java.lang.IllegalStateException: get field slot from row 0 col 2 failed 

當我這樣做：

dataSource = new CommentsDataSource(this); 
     dataSource.open(); 

     List<Comment> cmbs = dataSource.getAllComments(); 

Answer 1

您的身體投射字符串在您的情況下是錯誤的。你只查詢

private String[] allColumns = { MySQLiteHelper.CMB_ID, MySQLiteHelper.COLUMN_CMB };

添加其他兩個列名的allColumns字符串數組英寸 即MySQLiteHelper.COLUMN_INFO and MySQLiteHelper.COLUMN_URL

正確方法： private String[] allColumns = { MySQLiteHelper.CMB_ID, MySQLiteHelper.COLUMN_CMB, MySQLiteHelper.COLUMN_INFO, MySQLiteHelper.COLUMN_URL };

Answer 2

變化給出

Cursor cursor = database.query(MySQLiteHelper.TABLE_CMB, 
      allColumns, null, null, null, null,null); 

在方法

getAllComments（在甕代碼行） BCZ烏爾表名是在MySQLiteHelper其他由給出TABLE_CMBS

Cursor cursor = database.query(MySQLiteHelper.TABLE_CMBS, 
      allColumns, null, null, null, null,null);