首先总结哈

1 关于PreparedStatement 和statement

更新和插入 一定要用PreparedStatement 防止字段带有‘’ ，即sql注入  

ex：

StringBuffer sql = new StringBuffer("UPDATE CH_T_SONG_INFO");

sql.append("  set  " );
sql.append(" SEQ=? , SONG_ID=? , CONTENT_NAME=? ,SINGER_ID=?, SINGER=? where SONG_ID='"+ chTMusicSourceInfo.getSongId() + "' and SINGER_ID='" + chTMusicSourceInfo.getSingerId()+ "' and status<>'2'" );

Connection conn = JdbcUtil.getConnection();
        ps = conn.prepareStatement(sql.toString());
ps.setObject(1, chTMusicSourceInfo.getSeq());
ps.setObject(2, chTMusicSourceInfo.getSongId());
ps.setObject(3, chTMusicSourceInfo.getContentName());
ps.setObject(4, chTMusicSourceInfo.getSingerId());

               ps.executeUpdate();

查询用statement

ex：

Statement stm = JdbcUtil.getStm();
ResultSet rs=stm.executeQuery("select SEQ_SONG_ALBUM_INFO.nextval from dual");
if (rs.next())
return rs.getLong(1);

推荐用PreparedStatement

2 出现游标超出问题是因为执行了sql语句，资源没关闭，

Connect可以执行一个循环时在清理，但是必须得清理，不然也会出现游标问题，而像PreparedStatement 和statement 用一次 必须关一次 否则超出游标

 

3 批处理(一定要用事务)

 static void createBatch() throws SQLException {      Connection conn = null;      PreparedStatement ps = null;      ResultSet rs = null;      try {       conn = JdbcUtils.getConnection();      conn setAutoCommit(false);     String sql = "insert into person(pid,name,birthday, money) values (?,?, ?, ?) ";       ps = conn.prepareStatement(sql);       for (int i = 0; i < 100; i++) {        ps.setInt(1, 3000+i);        ps.setString(2, "person" + i);        ps.setDate(3, new Date(System.currentTimeMillis()));        ps.setFloat(4, 100f + i);        ps.addBatch();       }       int[] is = ps.executeBatch();      JdbcUtil.getConnection().commit();    } finally {       JdbcUtils.free(rs, ps, conn);      }     }    }