Python SqlAlchemy使用方法

2.初始化連接：

from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index
from sqlalchemy.orm import sessionmaker, relationship
from sqlalchemy import create_engine
import os
basedir = os.path.abspath(os.path.dirname(__file__))

# 創建對象的基類:
Base = declarative_base()

2.創建表：

# 創建單表
class Users(Base):
    # 表名
    __tablename__ = ‘users‘
    # 表的結構:
    id = Column(Integer, primary_key=True)
    username = Column(String(32))
    password = Column(String(16))

初始化數據庫：

 def __init__(self, username, password):
    # 初始化數據庫
    self.username = username
    self.password = password
 

創建聯合唯一索引

# __table_args__(
#     UniqueConstraint("列名1","列名2","聯合唯一索引名"),
#     index("索引名","列名1","列名2"),
# ) #創建聯合唯一索引
__table_args__ = (
    UniqueConstraint(‘id‘, ‘username‘, name=‘uix_id_name‘),
    Index(‘ix_id_name‘, ‘username‘, ‘password‘),
)

3.創建映射

# 創建映射
class UserORMHelper(object):
    def __init__(self, database_name):
        DATABASE_PATH = os.path.join(basedir, database_name)
        SQLALCHEMY_DATABASE_URI = ‘sqlite:///‘ + DATABASE_PATH
        self.engine = create_engine(SQLALCHEMY_DATABASE_URI)
 

創建表

def create_db(self):
    # 創建表
    Base.metadata.create_all(self.engine)  # 創建表
    Session = sessionmaker(bind=self.engine)
    self.session = Session()

刪除表

def drop_db(self):
    # 刪除表
    Base.metadata.drop_all(self.engine)   #刪除表

4.接下來就是簡單的針對數據庫的增刪改查操作了，這些操作我是為了方便測試安裝自己的做了些修改，後面我會附上測試的代碼

插入數據

def addUser(self, users):
    # 插入數據
    isSucess=False
    usrsList=self.query_all_with_user_name_password(users)
    if(usrsList and len(usrsList)>0):#用戶已經註冊
       return False
    self.session.add(users)
    self.session.commit()
    isSucess=True
    return isSucess

刪除數據

def delete(self,users):
    # 刪除數據
    isSucess=False
    user1 = self.session.query(Users).filter_by(username=users.username).first()
    self.session.delete(user1)
    self.session.commit()
    isSucess=True
    return isSucess

修改

（1）匹配username修改password

def update_user_extra_by_user_name(self, users):
    # 匹配並且修改password
    isSucess = False
    self.session.query(Users).filter(Users.username == users.username).update({"password": users.password}, synchronize_session=‘evaluate‘)
    self.session.commit()
    isSucess=True
    return isSucess

（2）匹配password修改username

def update_user_name_by_user_extra(self, users):
    # 匹配並且修改name
    isSucess = False
    self.session.query(Users).filter(Users.password == users.password).update({"username": users.username}, synchronize_session=‘evaluate‘)
    self.session.commit()
    isSucess=True
    return isSucess

查詢

安password查詢所有

def query_all_with_user_extra(self, users):
    # 查詢相同password數據
    userList = self.session.query(Users).filter_by(password=users.password).all()
    return userList

安username查詢所有，但是只取其一

def query_one(self,users):
    # 查詢相同name數據，取一個
    userList=self.session.query(Users).filter_by(username=users.username).limit(1).all()
    self.session.commit()
    return userList

安username查詢但是只取第一條數據

    def query_first_with_user_name(self, users):
        # 查詢相同name數據，取第一個
        userList=self.session.query(Users).filter_by(username=users.username).first()
        return userList

安username，password查詢所有

def query_all_with_user_name_password(self, users):
    # 查詢所有相同於name，password數據
    userList=self.session.query(Users).filter_by(username=users.username,password=users.password).all()
    return userList

安username查詢所有

def query_all_with_user_name(self, users):
    # 查詢所有相同name數據
    userList=self.session.query(Users).filter_by(username=users.username).all()
    return userList

下面的是數據庫的測試代碼，寫測試我用的是TDD

import unittest
from UserORM import Users,UserORMHelper




TEST_DB = ‘test.db‘

class UserORMHelperTestCase(unittest.TestCase):



    def setUp(self):
        """Set up a blank temp database before each test"""
        self.helper=UserORMHelper("user.db")
        self.helper.drop_db()
        self.helper.create_db()


    def tearDown(self):
        """Destroy blank temp database after each test"""
        self.helper.drop_db()

    def test_add(self):
        # 插入測試
        isSuccess=self.helper.addUser(Users("tome", "tom jobn"))
        self.assertTrue(isSuccess)
        isSuccess=self.helper.addUser(Users("tome", "tom jobn"))
        self.assertFalse(isSuccess)


    def test_delete(self):
        # 刪除測試
        isSuccess = self.helper.addUser(Users("tome", "tom jobn"))
        self.assertTrue(isSuccess)
        isSucess=self.helper.delete(Users("tome", "tom jobn"))
        self.assertTrue(isSucess)

    def test_query_all(self):
        # 查詢所有相同name數據測試
         isSuccess=self.helper.addUser(Users("tome", "tom jobn"))
         self.assertTrue(isSuccess)
         isSuccess=self.helper.addUser(Users("tome", "tom jobn2"))
         self.assertTrue(isSuccess)
         isSuccess=self.helper.addUser(Users("tome", "tom jobn3"))
         self.assertTrue(isSuccess)
         userList=self.helper.query_all_with_user_name(Users("tome", "tom jobn"))
         # print userList
         self.assertEqual(len(userList),3)


    def test_query_none(self):
        # 查詢相同name數據，取第一個  測試
         userList=self.helper.query_first_with_user_name(Users("tom", "tom job"))
         self.assertEqual(userList,None)

    def test_query_one(self):
        # 查詢相同name數據，取一個   測試
        isSuccess = self.helper.addUser(Users("tome", "tom jobn"))
        self.assertTrue(isSuccess)
        isSuccess = self.helper.addUser(Users("tome", "tom jobn2"))
        self.assertTrue(isSuccess)
        isSuccess = self.helper.addUser(Users("tome", "tom jobn3"))
        self.assertTrue(isSuccess)
        userList = self.helper.query_one(Users("tome", "tom jobn4"))
        self.assertEqual(len(userList), 1)


    def test_revise_extra(self):
        isSuccess = self.helper.addUser(Users("tome", "tom jobn"))
        self.assertTrue(isSuccess)

        isSuccess=self.helper.update_user_extra_by_user_name(Users("tome", "tomUpdate"))

        self.assertTrue(isSuccess)
        userList = self.helper.query_all_with_user_name(Users("tome", "tom job"))
        self.assertEqual(len(userList), 1)


    def test_recise_name(self):
        isSuccess = self.helper.addUser(Users("tome", "tom jobn"))
        self.assertTrue(isSuccess)
        isSuccess = self.helper.update_user_name_by_user_extra(Users("tomeUpdate", "tom jobn"))
        self.assertTrue(isSuccess)
        userList = self.helper.query_all_with_user_name(Users("tomeUpdate", "tom job"))
        self.assertEqual(len(userList),1)















if __name__ == ‘__main__‘:
    unittest.main()

Python SqlAlchemy使用方法