diff --git a/.gitignore b/.gitignore
index 78690ef..bf9c300 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,4 +3,10 @@ pyelo/
 
 # config file
 setup.cfg
-.vscode/
\ No newline at end of file
+.vscode/
+
+# data
+*.db
+
+# cache
+__pycache__/
\ No newline at end of file
diff --git a/lib/db_init.py b/lib/db_init.py
new file mode 100644
index 0000000..5189eb6
--- /dev/null
+++ b/lib/db_init.py
@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+# -*- encoding: utf-8 -*-
+'''
+@File   :   db_init.py
+@Author :   liuyihui
+@Email  :   liuyihui02@gmail.com
+'''
+
+# here put the import lib
+from sqlalchemy import create_engine
+from sqlalchemy import Column, Integer, String, Float
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()
+
+class Person(Base):
+    __tablename__ = 'persons'
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    name = Column(String)
+    work = Column(String)
+    rate = Column(Float, default=1400)
+
+    def __repr__(self):
+        return "<Person(name='%s', work='%s', rate='%f')>" % (self.name, self.work, self.rate)
+
+
+if __name__ == '__main__':
+    engine = create_engine('sqlite:///data.db', echo=True)
+    Base.metadata.create_all(engine, checkfirst=True)
diff --git a/lib/elo.py b/lib/elo.py
index ed6035f..9eae196 100644
--- a/lib/elo.py
+++ b/lib/elo.py
@@ -8,60 +8,40 @@
 
 # here put the import lib
 import math
-from typing_extensions import Self
+from db_init import Person
 
-class Person(object):
-    '''personal information
+def __compute_wre(A: Person, B: Person) -> float:
+    '''compute win rate expectation (wre for short)
 
-    Attributes
+    Parameters
     ----------
-        rate : elo rate
-        name : name
-        sex  : male or female
-        link : baike link
+        A, B : two persons
 
-    Methods
+    Returns
     -------
-        compute_K : compute the constant K
+        wre : win rate expectation of A
     '''
-    def __init__(self, name: str, rate: float = 1400, *, sex: str = None, link: str = None) -> None:
-        self.name = name
-        self.rate = rate
-        self.link = link
+    wre = 1 / (1 + math.pow(10, (B.rate-A.rate)/400))
+    return wre
 
-        if sex and sex not in ['male', 'female']:
-            raise ValueError("Sex must be male or female")
-        self.sex = sex
+def __compute_K(P: Person) -> float:
+    if P.rate > 2400:
+        return 12
+    elif P.rate > 1900:
+        return 24
+    else:
+        return 36
 
-    def compute_wre(self, B: Self) -> float:
-        '''compute win rate expectation (wre for short)
+def set_result(A: Person, B: Person, res: float) -> None:
+    '''set result of this game
 
-        Parameters
-        ----------
-            B : another person
-
-        Returns
-        -------
-            wre : win rate expectation
-        '''
-        wre = 1 / (1 + math.pow(10, (B.rate-self.rate)/400))
-        return wre
-
-    def compute_K(self) -> float:
-        if self.rate > 2400:
-            return 12
-        elif self.rate > 2000:
-            return 24
-        else:
-            return 36
-
-    def set_result(self, wre: float, res: float) -> None:
-        '''set result of this game
-
-        Parameters
-        ----------
-            wre : win rate expectation
-            res : the result, 0 for lose, 1 for win and 0.5 for draw
-        '''
-        K = self.compute_K()
-        self.rate += K * (res - wre)
+    Parameters
+    ----------
+        A, B : two persons
+        res : the result, 0 for A win, 1 for B win and -1 for draw
+    '''
+    wre1 = __compute_wre(A, B)
+    wre2 = 1 - wre1
+    if res >= 0:
+        A.rate += __compute_K(A) * (1 - res - wre1)
+        B.rate += __compute_K(B) * (res - wre2)
diff --git a/lib/utils.py b/lib/utils.py
new file mode 100644
index 0000000..6c0f16c
--- /dev/null
+++ b/lib/utils.py
@@ -0,0 +1,48 @@
+#!/usr/bin/env python
+# -*- encoding: utf-8 -*-
+'''
+@File   :   utils.py
+@Author :   liuyihui
+@Email  :   liuyihui02@gmail.com
+'''
+
+# here put the import lib
+import elo
+import random
+from typing import List
+from db_init import Person
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+from sqlalchemy.orm.session import Session
+from sqlalchemy.sql.expression import desc, func
+
+engine = create_engine('sqlite:///data.db', echo=False)
+session_maker = sessionmaker(bind=engine)
+
+def get_session() -> Session:
+    return session_maker()
+
+def get_person(id: int, ses: Session) -> Person:
+    res = ses.query(Person).filter_by(id=id).first()
+    return res
+
+def get_enemy(P: Person, ses: Session, delta: float = 0.01) -> Person:
+    min_ = P.rate * (1 - delta)
+    max_ = P.rate * (1 + delta)
+
+    res = ses.query(Person).filter(
+        Person.id != P.id,
+        Person.rate >= min_,
+        Person.rate <= max_
+    ).order_by(func.random()).first()
+    return res
+
+def get_rank(ses: Session, b: int = 1, len: int = 10) -> List[Person]:
+    res = ses.query(Person).order_by(desc('rate')).offset(b-1).limit(len).all()
+    return res
+
+
+ses = get_session()
+A = get_person(1, ses)
+res = get_enemy(A, ses)
+print(res)
diff --git a/public/index.html b/public/index.html
index 8929845..81d44e3 100644
--- a/public/index.html
+++ b/public/index.html
@@ -43,7 +43,6 @@
                         </div>
                         <div style="margin: 2% auto;">
                             姓名：<p id="N1"></p><br />
-                            年龄：<p id="S1"></p><br />
                             代表作：<p id="M1"></p><br />
                         </div>
                     </div>
@@ -53,7 +52,6 @@
                         </div>
                         <div style="margin: 2% auto;">
                             姓名：<p id="N2"></p><br />
-                            年龄：<p id="S2"></p><br />
                             代表作：<p id="M2"></p><br />
                         </div>
                     </div>