Question

每次调试项目时，我的设备都会显示我的应用程序停止的对话框。这是我的代码。我不知道我的代码有什么问题。

public class Nasabah extends Activity {
DatabaseHelper db = new DatabaseHelper(this);
ArrayList<HashMap<String,String>> contactList;
private static final String TAG_NAME = "name";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_nasabah);

    final ListView listNasabah = (ListView) findViewById(R.id.listNasabah);

    Log.d("Insert: ", "Inserting...");
    db.addContact(new Contact("Jose Mourinho", "087888888888", "1088994444"));
    db.addContact(new Contact("Didier Drogba", "0878555555555", "1088996666"));
    db.addContact(new Contact("Eden Hazard", "0878511111111", "1088995555"));

    Log.d("Reading: ", "Reading all contacts...");
    List<Contact> contact = db.getAllContacts();

    contactList = new ArrayList<HashMap<String, String>>();
    for (Contact cn : contact){
        String log = "Id :"+cn.getId()+" ,Name: "+cn.getName()+" ,Telp: "+cn.getTelp()+" ,Rek: "+cn.getRek();
        Log.d("Name: ", log);

        String name = "" + cn.getName();
        HashMap <String, String> contacts = new HashMap<String, String>();

        contacts.put(TAG_NAME, name);
        contactList.add(contacts);
    }

    SimpleAdapter adapter = new SimpleAdapter(this, contactList, android.R.layout.simple_list_item_1, new String[]{TAG_NAME}, new int[]{android.R.id.text1});
    listNasabah.setAdapter(adapter);

    listNasabah.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            final String item = (String) parent.getItemAtPosition(position);
        }
    });
}}

这是我的 databasehelper.java ：

public class DatabaseHelper extends SQLiteOpenHelper{
private static final String DB_NAME = "BMIcontact.db";
private static final int DB_VER = 1;
private static final String TABLE_NAME = "contact";
private static final String COL_ID = "id_nasabah";
private static final String COL_NAME = "nama_nasabah";
private static final String COL_TELP = "telp";
private static final String COL_REK = "rekening";
public DatabaseHelper (Context context){
    super(context, DB_NAME, null, DB_VER);
    //super(context, Environment.getExternalStorageDirectory() + File.separator + "/DataBase/" + File.separator + DB_NAME, null, DB_VER);
}

@Override
public void onCreate(SQLiteDatabase db){
    String CREATE_CONTACT_TABLE = "CREATE TABLE" + TABLE_NAME + "(" + COL_ID + "INTEGER PRIMARY KEY," + COL_NAME
            + "TEXT," + COL_TELP + "TELP," + COL_REK + "TEXT" + ")";
    db.execSQL(CREATE_CONTACT_TABLE);
}
@Override
public void onUpgrade (SQLiteDatabase db, int oldVersion, int NewVersion){
    db.execSQL("DROP TABLE IF EXIST" + TABLE_NAME);
    onCreate(db);
}

void addContact (Contact contact){
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(COL_NAME, contact.getName());
    values.put(COL_TELP, contact.getTelp());
    values.put(COL_REK, contact.getRek());

    db.insert(TABLE_NAME, null, values);
    db.close();
}
Contact getContact (int id){
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.query(TABLE_NAME, new String[] { COL_ID, COL_NAME, COL_TELP, COL_REK}, COL_ID + "=?",
            new String[] {String.valueOf(id) }, null, null, null, null);
    if(cursor != null){
        cursor.moveToFirst();
    }
    Contact contact = new Contact(Integer.parseInt(cursor.getString(0)), cursor.getString(1), cursor.getString(2), cursor.getString(3));
    return contact;
}

public List<Contact> getAllContacts() {
    List<Contact> contactList = new ArrayList<Contact>();
    String selectQuery = "SELECT * FROM " + TABLE_NAME;

    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);

    if(cursor.moveToFirst()){
        do{
            Contact contact = new Contact();
            contact.setId(Integer.parseInt(cursor.getString(0)));
            contact.setName(cursor.getString(1));
            contact.setTelp(cursor.getString(2));
            contact.setRek(cursor.getString(3));

            contactList.add(contact);
        }while(cursor.moveToNext());
    }
    return contactList;
}

public int getContactsCount(){
    String countQuery = "SELECT * FROM " + TABLE_NAME;
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery(countQuery, null);
    cursor.close();

    return cursor.getCount();
}}

Answer 1

永远不会忘记sql关键字和表/列名称之间的空格：

CREATE TABLEcontact

或者你认为这可以执行吗？

{{1}}

Answer 2

我发现你在创建表格时犯了一个错误，你把COL_TELP定义为TELP而不是文本作为输入参数我认为

Answer 3

将数据库版本从1更改为2.

应用程序在调试时停止

3 个答案: