public String excuteTempSql(String sql_temp){
String front_id_string="12";
conn = DBUtil.getConnection();
try {
stmt = conn.createStatement();
rs = stmt.executeQuery(sql_temp);
while (rs.next()) {
front_id_string = front_id_string+rs.getInt("room_id")+",";
}
front_id_string= front_id_string.substring(0, front_id_string.length()-1 );
} catch (SQLException e) {
e.printStackTrace();
}
System.out.println(front_id_string);
return front_id_string;
}
为什么front_id_string赋值为“12”了(无论什么赋值),但是单点调试的时候显示为null。高层传到底层的sql_temp为查询语句。