import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
/**
 *
 * @author lai_zs
 * @date：2012-2-16 下午4:16:02
 */
public class DBHelper extends SQLiteOpenHelper {
  private static final int DATABASE_VERSION = 1;
  private static final String DATABASE_NAME = "autoComplete.db";
  // 根据name自动查询
  public static final String NAME = "name";
  public DBHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
  }
  @Override
  public void onCreate(SQLiteDatabase db) {
    String sqlString = "createtable test (_id integer primary key autoincrement,name varchat(20) not null onconflict fail)";
    db.execSQL(sqlString);
    // 初始数据库表
    String[] nameStrArrayStr = new String[] { "aaa", "abc", "cde", "中国", "美女", "提示" };
    for (int i = 0; i < nameStrArrayStr.length; i++) {
      db.execSQL("INSERT INTOtest(" + NAME + ")values(?)",new Object[] { nameStrArrayStr[i] });
    }
  }
  @Override
  public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {
    // do nothing here
  }
  /**
   * 根据输入内容模糊查询
   * @param name
   * @return
   */
  public Cursor query(String name) {
    SQLiteDatabase db = this.getReadableDatabase();
    return db.rawQuery("select* from test where name like '%" + name + "%' limit 10",null);
  }
}

import android.content.Context;
import android.database.Cursor;
import android.widget.SimpleCursorAdapter;
/**
 *
 * @author lai_zs
 * @date：2012-2-16 下午3:49:25
 */
public class AutoCompleteAdater extends SimpleCursorAdapter {
  private DBHelper dbHelper = null;
  private Context context;
  // 查询字段
  private String queryField;
  public AutoCompleteAdater(Context context, int layout, Cursor c,String from, int to) {
    super(context, layout, c, new String[] { from },new int[] { to });
    this.context = context;
    this.queryField = from;
  }
  /**
   * 动态查询数据库
   */
  @Override
  public Cursor runQueryOnBackgroundThread(CharSequenceconstraint) {
    if (constraint != null) {
      return getDbHelper().query((String) constraint);
    } else {
      return null;
    }
  }
  /**
   * 这里设置在弹出的提示列表中点击某一项后的返回值,返回值将被显示在文本框中
   */
  @Override
  public CharSequence convertToString(Cursor cursor) {
    return cursor.getString(cursor.getColumnIndex(queryField));
  }
  public DBHelper getDbHelper() {
    if (dbHelper == null) {
      dbHelper = new DBHelper(this.context);
    }
    return dbHelper;
  }
}

<AutoCompleteTextView
    android:id="@+id/autoCompleteTextView1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text=""
    android:hint="@string/dbAutoComlete" >
    <requestFocus />
</AutoCompleteTextView>

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    AutoCompleteAdatercursorAdapter = new AutoCompleteAdater(this, android.R.layout.simple_dropdown_item_1line,null, DBHelper.NAME, android.R.id.text1);
    // 设置输入一个字符就弹出提示列表(默认输入两个字符时才弹出提示)
    ((AutoCompleteTextView) this.findViewById(R.id.autoCompleteTextView1)).setThreshold(1);
    ((AutoCompleteTextView) this.findViewById(R.id.autoCompleteTextView1)).setAdapter(cursorAdapter);
}