Question

我需要连接一个表中的3列，并用分号分隔。经过研究，我决定使用xmlagg和getclobval（）-直到本周初它开始抛出ORA-1489时，它都运行良好-字符串连接的结果太长了。我使用xmlagg和getclobval（）来专门避免这种情况。目前，我仍在尝试查找有问题的行，但是希望有人确保我的代码正确无误。谢谢！

select id, 
   rtrim(extract(xmlagg(xmlelement(e, col1 || ';  ' || col2 || ';  ' || col3 || '; ')), 
           '/E/text()').getclobval(), chr(13)) AS concat_field from schema.table group by id

Answer 1

如果col1 + col2 + col3 + separators的长度> 4000，则串联引发错误。 // class variable will hold the currently loaded song private Song mCurrentSong; [...] viewHolder.playB.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { // MediaPlayer has not been initialized OR clicked song is not the currently loaded song if (mCurrentSong == null || song != mCurrentSong) { // Sets the currently loaded song mCurrentSong = song; mediaPlayer = MediaPlayer.create(context, song.getSong()); Toast.makeText(context, "Playing" + song.getName(), Toast.LENGTH_LONG).show(); } if (mediaPlayer.isPlaying()) { mediaPlayer.pause(); viewHolder.playB.setImageResource(R.drawable.play); } else { mediaPlayer.start(); viewHolder.playB.setImageResource(R.drawable.pause); } } }); viewHolder.stopB.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { // If currently loaded song is set the MediaPlayer must be initialized if (mCurrentSong != null) { mediaPlayer.stop(); mediaPlayer.release(); mCurrentSong = null; // Set back currently loaded song } viewHolder.playB.setImageResource(R.drawable.play); } });
解决方案：col1 || '; ' || col2 || '; ' || col3 || '; '

to_clob

XMLAGG抛出ORA-1489-无法弄清原因

1 个答案: