mysql-java关于dbutils的使用
mysqljavasejavadbutilssql
<code> /* * 查找评论 */ public List<comment> find(String blogID) { try { String sql = "select child.commentID,u.userName,child.commentContent,count(child.commentID) depth,child.commentParentID,child.commentTime from comment2 parent,comment2 child,user u where child.blogID = ? and child.blogID = parent.blogID and parent.left=child.right and child.userID = u.userID group by child.commentID order by child.left"; Object params[] = { blogID }; List<comment> list = qr.query(sql, new BeanListHandler<comment>( Comment.class), params); sql = "select u.userName from user u,comment c where c.commentID = ? and u.userID = c.userID"; for (int i = 0; i (), params1); Comment commentParent = qr.query(sql, new BeanHandler<comment>(Comment.class), params1); System.out.println(sql+ commentParent.getUserName() ); list.get(i).setCommentParent(commentParent); } } return list; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; }</comment></comment></comment></comment></code>
上面代码中,使用了dbutils这个工具,第一个sql语句能顺利查出结果,第二个sql语句什么都查不到,不管是用ScalarHandler还是beanHandler接收查到的数据都是空(userName和commentParent都为空),sql语句我在mysql试过了没问题能查出东西,param1[]里的东西也能正确传进去,可是就是查不出来,希望高手帮帮忙,帮我找找问题。

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