java-第二個sql語句得到的resultset對象是空的怎麼辦

第二個sql語句得到的resultset對象是空的怎麼辦

public ListgetAll1(String name) throws Exception {

Listresult = new ArrayList();

Connection con = DatabaseConnection.getConnection();

String na=null;

String sql1= "select * from guanzhu where guanzhu=?";

PreparedStatement ps1 = con.prepareStatement(sql1);

ps1.setString(1, name);

ResultSet rs1 = ps1.executeQuery();

while(rs1.next()){

Connection con1 = DatabaseConnection.getConnection();

na=rs1.getString("beiguanzhu");

String sql = "select * from message where author=? order by modified desc"; PreparedStatement ps = con1.prepareStatement(sql);

ps.setString(1, na); ResultSet rs = ps.executeQuery();

while (rs.next()) {

Message m = new Message();

m.setId(rs.getInt("id"));

m.setTitle(rs.getString("title"));

m.setContent(rs.getString("content"));

m.setModified(rs.getDate("modified"));

m.setAuthor(rs.getString("author"));

result.add(m);

System.out.println(rs.getString("author")+"");

}

}

return result;
}

最佳回答：

斷點一下，看看na等於多少，看看是不是一定沒有數據，其實你可以寫出來試下，先把第一個條件查出的Message集合放到一個臨時的list裡面，在用for循環查詢下，這樣試下也可以。