ANDROID数据库即使它是KEY_ID = _id也找不到列_id

这是我的错误。ANDROID数据库即使它是KEY_ID = _id也找不到列_id

无法启动活动：没有这样的列：_id（代码1）：同时编译：选择_id，名字从接触WHERE _id

Imade确保我的列拼写_id代替id我不明白为什么会发生这种情况。

public class DatabaseHandler extends SQLiteOpenHelper { 


// All Static variables 
private static final String TAG = "MyActivity"; 
// Database Version 
private static final int DATABASE_VERSION = 1; 

// Database Name 
private static final String DATABASE_NAME = "contactsManager"; 

// Contacts table name 
private static final String TABLE_CONTACTS = "contacts"; 

// Contacts Table Columns names 
public static final String KEY_ID = "_id"; 
public static final String KEY_NAME = "name"; 


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

// Creating Tables 
@Override 
public void onCreate(SQLiteDatabase db) { 
    String CREATE_CONTACTS_TABLE = " CREATE TABLE " + TABLE_CONTACTS + "(" 
      + KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT)"; 
    db.execSQL(CREATE_CONTACTS_TABLE); 
} 

// Upgrading database 
@Override 
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
    // Drop older table if existed 
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS); 

    // Create tables again 
    onCreate(db); 
} 

// Adding new contact 
void addAddress(String name) { 
    SQLiteDatabase db = this.getWritableDatabase(); 

    ContentValues values = new ContentValues(); 
    values.put(KEY_NAME, name); // Contact Name 


    // Inserting Row 
    db.insert(TABLE_CONTACTS, null, values); 
    db.close(); // Closing database connection 
} 

public boolean deleteAllAddresses() { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    int doneDelete = 0; 
    doneDelete = db.delete(TABLE_CONTACTS, null, null); 
    Log.w(TAG, Integer.toString(doneDelete)); 
    return doneDelete > 0; 

} 

public Cursor fetchAddressesbyName(String inputText) throws SQLException { 

    SQLiteDatabase db = this.getWritableDatabase(); 
    Log.w(TAG, inputText); 
    Cursor mCursor = null; 
    if (inputText == null || inputText.length() == 0) { 
     mCursor = db.query(TABLE_CONTACTS, new String[]{KEY_ID, 
         KEY_NAME,}, 
       null, null, null, null, null); 

    } else { 
     mCursor = db.query(true, TABLE_CONTACTS, new String[]{KEY_ID, 
         KEY_NAME,}, 
       KEY_NAME + " like '%" + inputText + "%'", null, 
       null, null, null, null); 
    } 
    if (mCursor != null) { 
     mCursor.moveToFirst(); 
    } 
    return mCursor; 

} 

    public Cursor fetchAllAddresses() { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    Cursor mCursor = db.query(TABLE_CONTACTS, new String[]{ KEY_ID, KEY_NAME,},KEY_ID , null,null,null, null); 

    if (mCursor != null) { 
     mCursor.moveToFirst(); 
    } 
    return mCursor; 
} 
}

这是我的接触类。

public class Contact { 
//private variables 
int id; 
String name=null; 

// getting ID 
public int getID(){ 
    return id; 
} 

// setting id 
public void setID(int id){ 
    this.id = id; 
} 

// getting name 
public String getName(){ 
    return name; 
} 

// setting name 
public void setName(String name){ 
    this.name = name; 
} 


}

来源

2015-04-07 anu

尝试将Database_Version从1升级到2 ...我认为这会对您有所帮助。

来源

2015-04-07 04:16:25

ANDROID数据库即使它是KEY_ID = _id也找不到列_id

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