虽然表中有很多行,但JDBC ResultSet只提供一行？

Question

我在表中有很多行,我在我的数据库上运行相同的查询,即MySql,但java ResultSet只给出表的第一行.这是我的代码.

public ArrayList<String> getAllAlbumsName(Integer uid) {
    ArrayList<String>allAlbumsName = new ArrayList<String>();
    try {
        String qstring = "SELECT albumname FROM picvik_picture_album WHERE " +
                "uid = '" + uid + "';";

        System.out.println(qstring);
        connection = com.picvik.util.MySqlConnection.getInstance().getConnection();
        ptmt = connection.prepareStatement(qstring);
        resultSet = ptmt.executeQuery();
        if(resultSet.next()) {
            System.out.println(resultSet.getString("albumname"));
            allAlbumsName.add(resultSet.getString("albumname"));
        }

        resultSet.close();
        ptmt.close();
        connection.close();


    } catch (Exception e) {
        e.printStackTrace();
    }   
    return allAlbumsName;
}

Answer 1

if(resultSet.next()) {
            System.out.println(resultSet.getString("albumname"));
            allAlbumsName.add(resultSet.getString("albumname"));
        }

如果你想获得所有行,它应该是:

while(resultSet.next()) {
        System.out.println(resultSet.getString("albumname"));
        allAlbumsName.add(resultSet.getString("albumname"));
    }

在而当特定的条件为真语句连续执行语句块

注意:正如@BalusC评论的那样,你的代码会引入SQL注入攻击,最好使用ptmt.set ...而不是手动构建SQL String.