java：Statement.RETURN_GENERATED_KEYS Err：S1000 Exp：结果集开始前

Question

我曾经执行过这个查询，没有任何问题，但是最近我一直有例外。

（MySQL服务器上）

48442 [NioProcessor-1] ERROR c.x.xpofacebook.mysql.MysqlDb - SQLException: Before start of result set 
48443 [NioProcessor-1] ERROR c.x.xpofacebook.mysql.MysqlDb - SQLState: S1000 
48443 [NioProcessor-1] ERROR c.x.xpofacebook.mysql.MysqlDb - VendorError: 0 
48451 [NioProcessor-1] ERROR c.x.xpofacebook.mysql.MysqlDb - stack trace: java.sql.SQLException: Before start of result set 

代码：

String createPlayerRow = "insert into highscore_challenge_player " 
      + "(fb_user_id,played,best_score,highscore_challenge_id) values ((select fb_user.id from fb_user where uid=?),?,?,?)"; 
     stmt.close(); 
     stmt = conn.prepareStatement(createPlayerRow,Statement.RETURN_GENERATED_KEYS); 
     stmt.setLong(1, uid); 
     stmt.setInt(2, 0); 
     stmt.setInt(3, 0); 
     stmt.setInt(4, highscoreChallengeId); 
     stmt.executeUpdate(); 
     rs = stmt.getGeneratedKeys(); 
     rowId = rs.getInt(1); <--- ERROR IN THIS LINE  

什么想法？ ！？

感谢

Answer 1

你需要to get to the first result之前，你可以开始寻找在它的项目。

更明确地说：您至少需要调用rs.next()一次才能访问结果。更一般地说，你需要调用next n次来查看第n行，并用sql结果，计数从1开始，而不是0.