java - Sqlite使用ListView插入数据

Question

我想将sqlitedb中的编辑文本值追加到顶部的新文本(索引0)，并在插入行时向下移动先前插入的数据(从索引1开始)...在顶部插入新行并显示它们在 ListView 中。我的代码适用于在底部附加行。

帮帮我..

dbhelper.java

public class DBhelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME = "REGISTRATION_DB";
public static final String TABLE_NAME = "REGISTRATION_TABLE";
public static final int VERSION = 1;
public static final String KEY_ID = "_id";
public static final String NAME = "NAME";
public static final String DB = "create table " + TABLE_NAME + " ("
  + KEY_ID + " integer primary key autoincrement, " + NAME
 + " text not null );";


    public DBhelper(Context context, String name,
            CursorFactory factory, int version) {
        super(context, name, factory, version);
        // TODO Auto-generated constructor stub
    }

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


    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
         db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);

    }

}

数据操作.java

SQLiteDatabase database_ob;
 DBhelper openHelper_ob;
 Context context;


 public Dataoper(Context c) {
    // TODO Auto-generated constructor stub

 context=c;

 }

public Dataoper opnToRead() {
      openHelper_ob = new DBhelper(context,
        openHelper_ob.DATABASE_NAME, null, openHelper_ob.VERSION);
      database_ob = openHelper_ob.getReadableDatabase();
      return this;

     }

public Dataoper opnToWrite() {
      openHelper_ob = new DBhelper(context,
        openHelper_ob.DATABASE_NAME, null, openHelper_ob.VERSION);
      database_ob = openHelper_ob.getWritableDatabase();
      return this;

     }

 public void Close() {
      database_ob.close();
     }

public long insertData(String fname) {
      ContentValues contentValues = new ContentValues();
      contentValues.put(openHelper_ob.NAME, fname);
      opnToWrite();
      long val = database_ob.insert(openHelper_ob.TABLE_NAME, null,
        contentValues);
      Close();
      return val;

     }

 public Cursor readdata() {
      String[] cols = { openHelper_ob.KEY_ID, openHelper_ob.NAME };
      opnToWrite();
      @SuppressWarnings("static-access")
    Cursor c = database_ob.query(openHelper_ob.TABLE_NAME, cols, null,
        null, null, null, null);

      return c;

     }
 public Cursor queryAll(int nameId) {
      String[] cols = { openHelper_ob.KEY_ID, openHelper_ob.NAME};
      opnToWrite();
      Cursor c = database_ob.query(openHelper_ob.TABLE_NAME, cols,
        openHelper_ob.KEY_ID + "=" + nameId, null, null, null, null);

      return c;

     }

Mainactivity.java

public class MainActivity extends Activity {
ListView lv;
Dataoper adapter_ob;
DBhelper helper_ob;
SQLiteDatabase db_ob;
Button bt;
Cursor cursor;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        lv=(ListView)findViewById(R.id.list);
        bt=(Button)findViewById(R.id.bt);
        adapter_ob = new Dataoper(this);

          String[] from = { DBhelper.NAME };
          int[] to = { R.id.name };
          cursor = adapter_ob.readdata();
          SimpleCursorAdapter cursorAdapter = new SimpleCursorAdapter(this,
            R.layout.listitem_row, cursor, from, to);
          lv.setAdapter(cursorAdapter);

        bt.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
Intent i= new Intent(MainActivity.this, Second.class);

                startActivity(i);
            }
        });
    }


}

Answer 1

您可以先显示由查询插入到最后的值

从 REGISTRATION_TABLE orderby _id ASEC 中选择 NAME

执行此查询时，您将获取游标值。根据游标值，您需要创建数组列表并将该数组列表传递给Arrayadapter。

Arraylist<String> al=new ArrayList<String>();
cursor cursor=db.rawquery("select NAME from REGISTRATION_TABLE orderby _id ASEC",null);
if(cursor.getcount()!=0)
{ 
 cursor.movetofirst();

 do{
  al.add(cursor.getstring(0));
  }
while(cursor.movetonext());
}

cursor.close();

Arrayadapter adapter=new Arrayadapter(this,R.layout.simple_list_item_1,al);
lv.setadapter(adapter);