SQLite的小例子--备忘录(3)

import android.content.Context; 
import android.database.Cursor; 
import android.database.SQLException; 
import android.database.sqlite.SQLiteDatabase; 
 
public class MyAdapter { 
    public static final String KEY_ROWID = "_id"; 
    public static final String KEY_CATEGORY = "category"; 
    public static final String KEY_SUMMARY = "summary"; 
    public static final String KEY_DESCRIPTION = "description"; 
    public static final String DATABASE_TABLE = "test"; 
    private Context context; 
    private SQLiteDatabase db; 
    private MySQLiteOpenHelper dbHelper; 
     
    public MyAdapter(Context context) 
    { 
        this.context = context; 
    } 
     
    public MyAdapter open() throws SQLException 
    { 
        dbHelper = new MySQLiteOpenHelper(context); 
        db = dbHelper.getWritableDatabase(); 
        return this; 
    } 
     
    public void close() 
    { 
        dbHelper.close(); 
    } 
    /**
     * 创建一个新的标test，如果test成功创建则返回一个新的列id，否则返回-1来表示失败
     */ 
    public long createTest(String category, String summary, String description) 
    { 
        ContentValues initialValues = createContentValues(category, summary, description); 
        return db.insert(DATABASE_TABLE, null, initialValues); 
    } 
    //更新表test 
    public boolean updateTest(long rowId, String category, String summary, String description) 
    { 
        ContentValues updateValues = createContentValues(category, summary, description); 
        return db.update(DATABASE_TABLE, updateValues, KEY_ROWID + "=" +rowId, null)>0; 
    } 
    //删除表test 
    public boolean deleteTest(long rowId)