例子中不知道map1.put("value", "'小红'")在小红还要加上一个单引号说因为是变量可以更详细地说明一下吗

Question

public static void main(String[] args) {List<Map<String, Object>> list=new ArrayList(); Map<String,Object> map1=new HashMap<>(); map1.put("name", "user_name"); map1.put("rela", "="); map1.put("value", "'小红'"); list.add(map1); List<Gooddes> gList=dGooddesDao.query(list); for(Gooddes gooddes:gList){ System.out.println(gooddes.toString()); }} public List<Gooddes> query(List<Map<String, Object>> params){ Connection conn=Jdbc_util.getConnection(); PreparedStatement statement=null; Gooddes g=null; StringBuffer sql=new StringBuffer("select * from imooc_goddess where 1=1 "); List<Gooddes> list=new ArrayList<>(); if(params!=null&&params.size()>0){ for (int a=0;a<params.size();a++){ Map<String, Object> map=params.get(a); sql.append(" and "+map.get("name")); sql.append(" "+map.get("rela")); sql.append(" "+map.get("value")); } } try { statement=conn.prepareStatement(sql.toString()); ResultSet rs=statement.executeQuery(); while (rs.next()) { g=new Gooddes(); g.setId(rs.getInt("id")); g.setUser_name(rs.getString("user_name")); g.setAge(rs.getInt("age")); g.setSex(rs.getInt("sex")); g.setBirthday(rs.getDate("birthday")); g.setEmail(rs.getString("email")); g.setMobile(rs.getString("mobile")); g.setCreate_date(rs.getDate("create_date")); g.setCreate_user(rs.getString("create_user")); g.setUpdate_date(rs.getDate("update_date")); g.setUpdate_user(rs.getString("update_user")); g.setIsdel(rs.getInt("isdel")); list.add(g); } } catch (SQLException e) { e.printStackTrace(); } return list; }