需要基于通过java中以前的sql查询检索到的值，通过sql检索数据库行值

我的代码是这样的

DataBaseUtil dbBaseUtil=new DataBaseUtil();
Connection con=dbBaseUtil.getConnection();

String query="select case_id, ticket_id from VAPP_ITEM where
(person1_alt_email='" + username +"') and ticket_type='Service Request' and       ticket_status not in ('Closed','Resolved')";

ResultSet rs=dbBaseUtil.getDbResultSet(query);
List<String> tickets=new ArrayList<String>();
while(rs.next())
ticket.add(rs.getString("case_Id")+"-"+rs.getString("ticket_Id"));

MyTicketUtil.searchAndOpenTicket(webui, "", tickets.get(0));

但这不起作用-控制台显示以下错误：

---

com.microsoft.sqlserver.jdbc.SQLServerException:找不到列“rs”或用户定义函数或聚合“rs.getString”，或名称不明确。

您已将

rs.getString（）

包含在字符串文字中

您应该使用

PreparedStatement

进行以下操作：

quer1 = "SELECT ticket_status FROM vapp_item WHERE case_id=? AND ticket_id = ?";
PreparedStatement pstm = conn.prepareStatement(quer1);
while (rs1.next())
    {
    pstm.setString(1, rs.getString(1));
    pstm.setString(2, rs.getString(2));
    rs2 = pstm.executeQuery();
    ...
    }

quer1 = "SELECT ticket_status FROM vapp_item WHERE case_id=? AND ticket_id = ?";
PreparedStatement pstm = conn.prepareStatement(quer1);
while (rs1.next())
    {
    pstm.setString(1, rs.getString(1));
    pstm.setString(2, rs.getString(2));
    rs2 = pstm.executeQuery();
    ...
    }