{
 "cells": [
  {
   "metadata": {},
   "cell_type": "markdown",
   "source": [
    "### ORM(Object Relational Mapping)\n",
    "- 데이터베이스 테이블을 파이썬의 클래스로 매핑\n",
    "- 컬럼 == 속성\n",
    "- SQLALchemy 라이브러리가 ORM 지원"
   ],
   "id": "11f3431eb6bf7a12"
  },
  {
   "cell_type": "code",
   "id": "initial_id",
   "metadata": {
    "collapsed": true,
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.531519156Z",
     "start_time": "2026-06-17T03:03:17.519312421Z"
    }
   },
   "source": "# !pip install sqlalchemy",
   "outputs": [],
   "execution_count": 36
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.555640871Z",
     "start_time": "2026-06-17T03:03:17.532414273Z"
    }
   },
   "cell_type": "code",
   "source": [
    "# Users 테이블 (id, name, email)\n",
    "# create table users()\n",
    "from sqlalchemy import Column, Integer, String, create_engine\n",
    "from sqlalchemy.orm import declarative_base, sessionmaker\n",
    "\n",
    "# 1.x 버전 코드\n",
    "# 데이터베이스 연결\n",
    "# 애플리케이션 당 하나만 만들어 사용\n",
    "# echo=True : 실행 SQL 을 콘솔에 추력\n",
    "engine = create_engine('sqlite:///db/users.db', echo=True)\n",
    "# engine = create_engine('sqlite:///users.db')\n",
    "\n",
    "# 모든 모델 크래스의 부모 클래스가 될 Base 객체 생성\n",
    "Base = declarative_base()\n",
    "\n",
    "# 데이터베이스랑 관련있는 클래스 : 모델 클래스\n",
    "class User(Base):\n",
    "    # 테이블 이름 지정\n",
    "    __tablename__ = 'users'\n",
    "\n",
    "    id = Column(Integer, primary_key=True)\n",
    "    name = Column(String)\n",
    "    email = Column(String, unique=True)\n",
    "\n",
    "    def __str__(self):\n",
    "        return f\"<User(name='{self.name}', email='{self.email}')>\"\n",
    "\n",
    "# 테이블 생성 ( 없는 경우만 새로 생성됨 )\n",
    "Base.metadata.create_all(engine)"
   ],
   "id": "7a41f863de1efd48",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,542 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,543 INFO sqlalchemy.engine.Engine PRAGMA main.table_info(\"users\")\n",
      "2026-06-17 12:03:17,545 INFO sqlalchemy.engine.Engine [raw sql] ()\n",
      "2026-06-17 12:03:17,548 INFO sqlalchemy.engine.Engine COMMIT\n"
     ]
    }
   ],
   "execution_count": 37
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.576534965Z",
     "start_time": "2026-06-17T03:03:17.557316858Z"
    }
   },
   "cell_type": "code",
   "source": [
    "# 모든 테이블 삭제\n",
    "Base.metadata.drop_all(engine)"
   ],
   "id": "28ae00aa8564cd68",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,561 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,563 INFO sqlalchemy.engine.Engine PRAGMA main.table_info(\"users\")\n",
      "2026-06-17 12:03:17,563 INFO sqlalchemy.engine.Engine [raw sql] ()\n",
      "2026-06-17 12:03:17,565 INFO sqlalchemy.engine.Engine \n",
      "DROP TABLE users\n",
      "2026-06-17 12:03:17,566 INFO sqlalchemy.engine.Engine [no key 0.00051s] ()\n",
      "2026-06-17 12:03:17,571 INFO sqlalchemy.engine.Engine COMMIT\n"
     ]
    }
   ],
   "execution_count": 38
  },
  {
   "metadata": {},
   "cell_type": "markdown",
   "source": "#### text() : 원시 SQL 실행",
   "id": "d4b2b34ebf185234"
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.599302675Z",
     "start_time": "2026-06-17T03:03:17.577699609Z"
    }
   },
   "cell_type": "code",
   "source": [
    "from sqlalchemy import text\n",
    "\n",
    "engine = create_engine('sqlite:///db/demo.db', echo=True)\n",
    "with engine.connect() as conn:\n",
    "    conn.execute(text(\"\"\"\n",
    "    CREATE TABLE IF NOT EXISTS users (\n",
    "    id INTEGER PRIMARY KEY AUTOINCREMENT,\n",
    "    name TEXT NOT NULL,\n",
    "    age INTEGER\n",
    "    )\n",
    "    \"\"\"\n",
    "    ))\n",
    "\n",
    "    conn.commit()\n",
    "    # 삽입\n",
    "    conn.execute(text(\"\"\"\n",
    "    INSERT INTO users (name, age) VALUES (:name, :age)\"\"\"),\n",
    "    [{\"name\" : \"Alice\", \"age\" : 23}, {\"name\":\"Bob\", \"age\" : 24}])\n",
    "\n",
    "    conn.commit()\n",
    "\n",
    "    # 조회\n",
    "    result = conn.execute(text(\"\"\"\n",
    "    SELECT * FROM users\n",
    "    \"\"\"))\n",
    "\n",
    "    for row in result:\n",
    "        print(row.id, row.name, row.age)"
   ],
   "id": "de1ebcd8f162fd42",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,581 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,581 INFO sqlalchemy.engine.Engine \n",
      "    CREATE TABLE IF NOT EXISTS users (\n",
      "    id INTEGER PRIMARY KEY AUTOINCREMENT,\n",
      "    name TEXT NOT NULL,\n",
      "    age INTEGER\n",
      "    )\n",
      "    \n",
      "2026-06-17 12:03:17,582 INFO sqlalchemy.engine.Engine [generated in 0.00126s] ()\n",
      "2026-06-17 12:03:17,583 INFO sqlalchemy.engine.Engine COMMIT\n",
      "2026-06-17 12:03:17,584 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,585 INFO sqlalchemy.engine.Engine \n",
      "    INSERT INTO users (name, age) VALUES (?, ?)\n",
      "2026-06-17 12:03:17,585 INFO sqlalchemy.engine.Engine [generated in 0.00116s] [('Alice', 23), ('Bob', 24)]\n",
      "2026-06-17 12:03:17,586 INFO sqlalchemy.engine.Engine COMMIT\n",
      "2026-06-17 12:03:17,591 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,593 INFO sqlalchemy.engine.Engine \n",
      "    SELECT * FROM users\n",
      "    \n",
      "2026-06-17 12:03:17,593 INFO sqlalchemy.engine.Engine [generated in 0.00211s] ()\n",
      "1 Alice 23\n",
      "2 Bob 24\n",
      "3 Alice 23\n",
      "4 Bob 24\n",
      "5 Alice 23\n",
      "6 Bob 24\n",
      "2026-06-17 12:03:17,595 INFO sqlalchemy.engine.Engine ROLLBACK\n"
     ]
    }
   ],
   "execution_count": 39
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.624396207Z",
     "start_time": "2026-06-17T03:03:17.600052176Z"
    }
   },
   "cell_type": "code",
   "source": [
    "# 2.x 버전 코드\n",
    "from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column\n",
    "from sqlalchemy import DateTime, func\n",
    "from datetime import datetime\n",
    "\n",
    "\n",
    "engine = create_engine('sqlite:///db/users.db', echo=True)\n",
    "# engine = create_engine('sqlite:///users.db')\n",
    "\n",
    "# 모든 모델 크래스의 부모 클래스가 될 Base 객체 생성\n",
    "class Base(DeclarativeBase):\n",
    "    pass\n",
    "\n",
    "# 데이터베이스랑 관련있는 클래스 : 모델 클래스\n",
    "class User(Base):\n",
    "    # 테이블 이름 지정\n",
    "    __tablename__ = 'users'\n",
    "\n",
    "    # 컬럽 타입 지정 : 티입힌트(파이썬 데이터 타입) 사용\n",
    "    id:Mapped[int] = mapped_column(primary_key=True, autoincrement=True)\n",
    "    name:Mapped[str]\n",
    "    email:Mapped[str] = mapped_column(unique=True)\n",
    "    age:Mapped[int]\n",
    "    created_at:Mapped[datetime] = mapped_column(DateTime, server_default=func.now())\n",
    "\n",
    "    def __str__(self):\n",
    "        return f\"<User(name='{self.name}', email='{self.email}')>\"\n",
    "\n",
    "# 테이블 생성 ( 없는 경우만 새로 생성됨 )\n",
    "# create_all() : IF NOT EXISTS\n",
    "Base.metadata.create_all(engine)"
   ],
   "id": "d7eb9178f27499a7",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,606 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,607 INFO sqlalchemy.engine.Engine PRAGMA main.table_info(\"users\")\n",
      "2026-06-17 12:03:17,609 INFO sqlalchemy.engine.Engine [raw sql] ()\n",
      "2026-06-17 12:03:17,610 INFO sqlalchemy.engine.Engine PRAGMA temp.table_info(\"users\")\n",
      "2026-06-17 12:03:17,610 INFO sqlalchemy.engine.Engine [raw sql] ()\n",
      "2026-06-17 12:03:17,612 INFO sqlalchemy.engine.Engine \n",
      "CREATE TABLE users (\n",
      "\tid INTEGER NOT NULL, \n",
      "\tname VARCHAR NOT NULL, \n",
      "\temail VARCHAR NOT NULL, \n",
      "\tage INTEGER NOT NULL, \n",
      "\tcreated_at DATETIME DEFAULT CURRENT_TIMESTAMP NOT NULL, \n",
      "\tPRIMARY KEY (id), \n",
      "\tUNIQUE (email)\n",
      ")\n",
      "\n",
      "\n",
      "2026-06-17 12:03:17,613 INFO sqlalchemy.engine.Engine [no key 0.00171s] ()\n",
      "2026-06-17 12:03:17,618 INFO sqlalchemy.engine.Engine COMMIT\n"
     ]
    }
   ],
   "execution_count": 40
  },
  {
   "metadata": {},
   "cell_type": "markdown",
   "source": [
    "#### 세션\n",
    "- 데이터베이스 연동\n",
    "- 변경사항 추적하고 트랜잭션 관리\n",
    "- sessionmaker 팩토리 사용"
   ],
   "id": "de5e7ee1adb4cee6"
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.633680827Z",
     "start_time": "2026-06-17T03:03:17.625430327Z"
    }
   },
   "cell_type": "code",
   "source": [
    "# 세션 팩토리 생성\n",
    "Session = sessionmaker(bind=engine, autoflush=False, autocommit=False)\n",
    "# 세션 객체 생성\n",
    "session = Session()"
   ],
   "id": "140093069c78dd21",
   "outputs": [],
   "execution_count": 41
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.647449353Z",
     "start_time": "2026-06-17T03:03:17.637405010Z"
    }
   },
   "cell_type": "code",
   "source": "session.close()",
   "id": "c9f8fdb361307ea",
   "outputs": [],
   "execution_count": 42
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.667693242Z",
     "start_time": "2026-06-17T03:03:17.648384205Z"
    }
   },
   "cell_type": "code",
   "source": [
    "# insert\n",
    "# session.add() / session.add_all() / session.commit()\n",
    "\n",
    "session = Session()\n",
    "# 사용자 생성\n",
    "new_User = User(name=\"Alice\", email=\"alice@example.com\", age=23)\n",
    "session.add(new_User)\n",
    "session.commit()\n",
    "session.close()"
   ],
   "id": "8c0f8f2c60597d73",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,651 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,654 INFO sqlalchemy.engine.Engine INSERT INTO users (name, email, age) VALUES (?, ?, ?) RETURNING id, created_at\n",
      "2026-06-17 12:03:17,655 INFO sqlalchemy.engine.Engine [generated in 0.00099s] ('Alice', 'alice@example.com', 23)\n",
      "2026-06-17 12:03:17,658 INFO sqlalchemy.engine.Engine COMMIT\n"
     ]
    }
   ],
   "execution_count": 43
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.691852173Z",
     "start_time": "2026-06-17T03:03:17.669654096Z"
    }
   },
   "cell_type": "code",
   "source": [
    "with Session() as session:\n",
    "    session.add_all(\n",
    "        [\n",
    "            User(name=\"Bob\", email=\"bob@example.com\", age=25),\n",
    "            User(name=\"Charlie\", email=\"charlie@example.com\", age=30),\n",
    "        ]\n",
    "    )\n",
    "    session.commit()"
   ],
   "id": "2c91d42f265ded17",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,672 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,674 INFO sqlalchemy.engine.Engine INSERT INTO users (name, email, age) VALUES (?, ?, ?) RETURNING id, created_at\n",
      "2026-06-17 12:03:17,675 INFO sqlalchemy.engine.Engine [generated in 0.00009s (insertmanyvalues) 1/2 (ordered; batch not supported)] ('Bob', 'bob@example.com', 25)\n",
      "2026-06-17 12:03:17,676 INFO sqlalchemy.engine.Engine INSERT INTO users (name, email, age) VALUES (?, ?, ?) RETURNING id, created_at\n",
      "2026-06-17 12:03:17,676 INFO sqlalchemy.engine.Engine [insertmanyvalues 2/2 (ordered; batch not supported)] ('Charlie', 'charlie@example.com', 30)\n",
      "2026-06-17 12:03:17,678 INFO sqlalchemy.engine.Engine COMMIT\n"
     ]
    }
   ],
   "execution_count": 44
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.733033419Z",
     "start_time": "2026-06-17T03:03:17.693025923Z"
    }
   },
   "cell_type": "code",
   "source": [
    "from sqlalchemy import select\n",
    "\n",
    "with Session() as session:\n",
    "    # id 를 사용해 조회\n",
    "    user = session.get(User, 1)\n",
    "    print(\"--- 단일 사용자 ---\")\n",
    "    print(user)\n",
    "\n",
    "    print(\"--- 모든 사용자 ---\")\n",
    "    all_users = session.query(User).all()\n",
    "    for user in all_users:\n",
    "        print(user)\n",
    "\n",
    "    stmt = select(User)\n",
    "    all_users = session.scalars(stmt)\n",
    "    for user in all_users:\n",
    "        print(user)\n",
    "\n",
    "    print(\"--- where ---\")\n",
    "    alice = session.query(User).filter_by(name = \"Alice\").first()\n",
    "    print(f\"찾은 사용자 {alice}\")\n",
    "\n",
    "    stmt = select(User).where(User.age >= 30)\n",
    "    find_users = session.scalars(stmt).all()\n",
    "    for user in find_users:\n",
    "        print(user)\n",
    "\n",
    "    stmt = select(User).where(User.email.like('%ali%'))\n",
    "    find_users = session.scalars(stmt).all()\n",
    "    for user in find_users:\n",
    "        print(user)\n",
    "\n",
    "    stmt = select(User).order_by(User.id.desc()).limit(2)\n",
    "    find_users = session.scalars(stmt).all()\n",
    "    for user in find_users:\n",
    "        print(user)\n",
    "\n",
    "    # 집계 함수\n",
    "    count = session.scalar(select(func.count()).select_from(User))\n",
    "    print(count)"
   ],
   "id": "b0ce2cc0ee9d68ed",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,698 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,704 INFO sqlalchemy.engine.Engine SELECT users.id AS users_id, users.name AS users_name, users.email AS users_email, users.age AS users_age, users.created_at AS users_created_at \n",
      "FROM users \n",
      "WHERE users.id = ?\n",
      "2026-06-17 12:03:17,704 INFO sqlalchemy.engine.Engine [generated in 0.00082s] (1,)\n",
      "--- 단일 사용자 ---\n",
      "<User(name='Alice', email='alice@example.com')>\n",
      "--- 모든 사용자 ---\n",
      "2026-06-17 12:03:17,706 INFO sqlalchemy.engine.Engine SELECT users.id AS users_id, users.name AS users_name, users.email AS users_email, users.age AS users_age, users.created_at AS users_created_at \n",
      "FROM users\n",
      "2026-06-17 12:03:17,707 INFO sqlalchemy.engine.Engine [generated in 0.00096s] ()\n",
      "<User(name='Alice', email='alice@example.com')>\n",
      "<User(name='Bob', email='bob@example.com')>\n",
      "<User(name='Charlie', email='charlie@example.com')>\n",
      "2026-06-17 12:03:17,710 INFO sqlalchemy.engine.Engine SELECT users.id, users.name, users.email, users.age, users.created_at \n",
      "FROM users\n",
      "2026-06-17 12:03:17,711 INFO sqlalchemy.engine.Engine [generated in 0.00100s] ()\n",
      "<User(name='Alice', email='alice@example.com')>\n",
      "<User(name='Bob', email='bob@example.com')>\n",
      "<User(name='Charlie', email='charlie@example.com')>\n",
      "--- where ---\n",
      "2026-06-17 12:03:17,713 INFO sqlalchemy.engine.Engine SELECT users.id AS users_id, users.name AS users_name, users.email AS users_email, users.age AS users_age, users.created_at AS users_created_at \n",
      "FROM users \n",
      "WHERE users.name = ?\n",
      " LIMIT ? OFFSET ?\n",
      "2026-06-17 12:03:17,714 INFO sqlalchemy.engine.Engine [generated in 0.00058s] ('Alice', 1, 0)\n",
      "찾은 사용자 <User(name='Alice', email='alice@example.com')>\n",
      "2026-06-17 12:03:17,718 INFO sqlalchemy.engine.Engine SELECT users.id, users.name, users.email, users.age, users.created_at \n",
      "FROM users \n",
      "WHERE users.age >= ?\n",
      "2026-06-17 12:03:17,719 INFO sqlalchemy.engine.Engine [generated in 0.00090s] (30,)\n",
      "<User(name='Charlie', email='charlie@example.com')>\n",
      "2026-06-17 12:03:17,720 INFO sqlalchemy.engine.Engine SELECT users.id, users.name, users.email, users.age, users.created_at \n",
      "FROM users \n",
      "WHERE users.email LIKE ?\n",
      "2026-06-17 12:03:17,721 INFO sqlalchemy.engine.Engine [generated in 0.00080s] ('%ali%',)\n",
      "<User(name='Alice', email='alice@example.com')>\n",
      "2026-06-17 12:03:17,723 INFO sqlalchemy.engine.Engine SELECT users.id, users.name, users.email, users.age, users.created_at \n",
      "FROM users ORDER BY users.id DESC\n",
      " LIMIT ? OFFSET ?\n",
      "2026-06-17 12:03:17,724 INFO sqlalchemy.engine.Engine [generated in 0.00092s] (2, 0)\n",
      "<User(name='Charlie', email='charlie@example.com')>\n",
      "<User(name='Bob', email='bob@example.com')>\n",
      "2026-06-17 12:03:17,727 INFO sqlalchemy.engine.Engine SELECT count(*) AS count_1 \n",
      "FROM users\n",
      "2026-06-17 12:03:17,728 INFO sqlalchemy.engine.Engine [generated in 0.00053s] ()\n",
      "3\n",
      "2026-06-17 12:03:17,728 INFO sqlalchemy.engine.Engine ROLLBACK\n"
     ]
    }
   ],
   "execution_count": 45
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.756463366Z",
     "start_time": "2026-06-17T03:03:17.734005295Z"
    }
   },
   "cell_type": "code",
   "source": [
    "with Session() as session:\n",
    "    alice = session.query(User).filter_by(name = \"Alice\").first()\n",
    "    alice.email = \"alice.new@example.com\"\n",
    "    session.commit()\n",
    "\n",
    "    print(f\"수정된 사용자 {session.query(User).filter_by(name='Alice').first()}\")"
   ],
   "id": "93f58b5307abd93f",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,737 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,739 INFO sqlalchemy.engine.Engine SELECT users.id AS users_id, users.name AS users_name, users.email AS users_email, users.age AS users_age, users.created_at AS users_created_at \n",
      "FROM users \n",
      "WHERE users.name = ?\n",
      " LIMIT ? OFFSET ?\n",
      "2026-06-17 12:03:17,740 INFO sqlalchemy.engine.Engine [cached since 0.02646s ago] ('Alice', 1, 0)\n",
      "2026-06-17 12:03:17,741 INFO sqlalchemy.engine.Engine UPDATE users SET email=? WHERE users.id = ?\n",
      "2026-06-17 12:03:17,742 INFO sqlalchemy.engine.Engine [generated in 0.00075s] ('alice.new@example.com', 1)\n",
      "2026-06-17 12:03:17,743 INFO sqlalchemy.engine.Engine COMMIT\n",
      "2026-06-17 12:03:17,747 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,749 INFO sqlalchemy.engine.Engine SELECT users.id AS users_id, users.name AS users_name, users.email AS users_email, users.age AS users_age, users.created_at AS users_created_at \n",
      "FROM users \n",
      "WHERE users.name = ?\n",
      " LIMIT ? OFFSET ?\n",
      "2026-06-17 12:03:17,749 INFO sqlalchemy.engine.Engine [cached since 0.03613s ago] ('Alice', 1, 0)\n",
      "수정된 사용자 <User(name='Alice', email='alice.new@example.com')>\n",
      "2026-06-17 12:03:17,751 INFO sqlalchemy.engine.Engine ROLLBACK\n"
     ]
    }
   ],
   "execution_count": 46
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.785689642Z",
     "start_time": "2026-06-17T03:03:17.757935816Z"
    }
   },
   "cell_type": "code",
   "source": [
    "from sqlalchemy import update\n",
    "\n",
    "with Session() as session:\n",
    "    user = session.get(User, 1)\n",
    "    if user:\n",
    "        user.age = 40\n",
    "        session.commit()\n",
    "\n",
    "    # 일괄 업데이트\n",
    "    stmt = update(User).where(User.age <= 30).values(age=20)\n",
    "    session.execute(stmt)\n",
    "    session.commit()"
   ],
   "id": "1f333d8d8bcfbf54",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,761 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,762 INFO sqlalchemy.engine.Engine SELECT users.id AS users_id, users.name AS users_name, users.email AS users_email, users.age AS users_age, users.created_at AS users_created_at \n",
      "FROM users \n",
      "WHERE users.id = ?\n",
      "2026-06-17 12:03:17,763 INFO sqlalchemy.engine.Engine [cached since 0.0592s ago] (1,)\n",
      "2026-06-17 12:03:17,764 INFO sqlalchemy.engine.Engine UPDATE users SET age=? WHERE users.id = ?\n",
      "2026-06-17 12:03:17,766 INFO sqlalchemy.engine.Engine [generated in 0.00217s] (40, 1)\n",
      "2026-06-17 12:03:17,769 INFO sqlalchemy.engine.Engine COMMIT\n",
      "2026-06-17 12:03:17,773 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,775 INFO sqlalchemy.engine.Engine UPDATE users SET age=? WHERE users.age <= ?\n",
      "2026-06-17 12:03:17,776 INFO sqlalchemy.engine.Engine [generated in 0.00108s] (20, 30)\n",
      "2026-06-17 12:03:17,777 INFO sqlalchemy.engine.Engine COMMIT\n"
     ]
    }
   ],
   "execution_count": 47
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.805168757Z",
     "start_time": "2026-06-17T03:03:17.787206837Z"
    }
   },
   "cell_type": "code",
   "source": [
    "with Session() as session:\n",
    "    bob = session.query(User).filter_by(name=\"Bob\").first()\n",
    "    session.delete(bob)\n",
    "    session.commit()\n"
   ],
   "id": "f6c6f87020eb7927",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,790 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,791 INFO sqlalchemy.engine.Engine SELECT users.id AS users_id, users.name AS users_name, users.email AS users_email, users.age AS users_age, users.created_at AS users_created_at \n",
      "FROM users \n",
      "WHERE users.name = ?\n",
      " LIMIT ? OFFSET ?\n",
      "2026-06-17 12:03:17,793 INFO sqlalchemy.engine.Engine [cached since 0.07924s ago] ('Bob', 1, 0)\n",
      "2026-06-17 12:03:17,794 INFO sqlalchemy.engine.Engine DELETE FROM users WHERE users.id = ?\n",
      "2026-06-17 12:03:17,795 INFO sqlalchemy.engine.Engine [generated in 0.00093s] (2,)\n",
      "2026-06-17 12:03:17,797 INFO sqlalchemy.engine.Engine COMMIT\n"
     ]
    }
   ],
   "execution_count": 48
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.824210114Z",
     "start_time": "2026-06-17T03:03:17.807206458Z"
    }
   },
   "cell_type": "code",
   "source": [
    "from sqlalchemy import delete\n",
    "\n",
    "# delete from 테이블명 where id = 1\n",
    "with Session() as session:\n",
    "    stmt = delete(User).where(User.id == 1)\n",
    "    session.execute(stmt)\n",
    "    session.commit()"
   ],
   "id": "b35c028d86f48e31",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,810 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,811 INFO sqlalchemy.engine.Engine DELETE FROM users WHERE users.id = ?\n",
      "2026-06-17 12:03:17,812 INFO sqlalchemy.engine.Engine [generated in 0.00074s] (1,)\n",
      "2026-06-17 12:03:17,813 INFO sqlalchemy.engine.Engine COMMIT\n"
     ]
    }
   ],
   "execution_count": 49
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.834127797Z",
     "start_time": "2026-06-17T03:03:17.824909859Z"
    }
   },
   "cell_type": "code",
   "source": "Base.metadata.clear()",
   "id": "9da5d9421e56853f",
   "outputs": [],
   "execution_count": 50
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.863676311Z",
     "start_time": "2026-06-17T03:03:17.834932678Z"
    }
   },
   "cell_type": "code",
   "source": [
    "from sqlalchemy.orm import relationship\n",
    "from sqlalchemy import ForeignKey\n",
    "\n",
    "# 관계(외래키)\n",
    "# 1:N, N:1, M:N\n",
    "# 게시글 하나 : 댓글 여러개\n",
    "\n",
    "class Post(Base):\n",
    "    __tablename__ = 'posts'\n",
    "\n",
    "    id : Mapped[int] = mapped_column(primary_key=True, autoincrement=True)\n",
    "    title:Mapped[str] = mapped_column(String(200))\n",
    "    content:Mapped[str]\n",
    "    # 역참조\n",
    "    comments: Mapped[list['Comment']] = relationship('Comment', back_populates='post', cascade='all, delete-orphan')\n",
    "\n",
    "# FOREIGN KEY (post_id) REFERENCES posts(id);\n",
    "class Comment(Base):\n",
    "    __tablename__ = 'comments'\n",
    "\n",
    "    id : Mapped[int] = mapped_column(primary_key=True, autoincrement=True)\n",
    "    content:Mapped[str]\n",
    "    # 어느 게시글의 댓글인가?\n",
    "    post_id:Mapped[int] = mapped_column(ForeignKey(\"posts.id\"))\n",
    "    # 역참조\n",
    "    post:Mapped['Post'] = relationship('Post', back_populates='comments')\n"
   ],
   "id": "cc7b55c5bf90b92b",
   "outputs": [],
   "execution_count": 51
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.884050919Z",
     "start_time": "2026-06-17T03:03:17.864744917Z"
    }
   },
   "cell_type": "code",
   "source": "Base.metadata.create_all(engine)",
   "id": "50e66cc696cfdd21",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,868 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,872 INFO sqlalchemy.engine.Engine PRAGMA main.table_info(\"posts\")\n",
      "2026-06-17 12:03:17,873 INFO sqlalchemy.engine.Engine [raw sql] ()\n",
      "2026-06-17 12:03:17,873 INFO sqlalchemy.engine.Engine PRAGMA main.table_info(\"comments\")\n",
      "2026-06-17 12:03:17,874 INFO sqlalchemy.engine.Engine [raw sql] ()\n",
      "2026-06-17 12:03:17,876 INFO sqlalchemy.engine.Engine COMMIT\n"
     ]
    }
   ],
   "execution_count": 52
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.932695111Z",
     "start_time": "2026-06-17T03:03:17.885317745Z"
    }
   },
   "cell_type": "code",
   "source": [
    "with Session() as session:\n",
    "    post = Post(title=\"LLM 입문\", content=\"LLM이란 무엇인가?\")\n",
    "    post.comments = [\n",
    "        Comment(content=\"LLM은 언어 모델의 일종입니다.\"),\n",
    "        Comment(content=\"좋아요\"),\n",
    "\n",
    "    ]\n",
    "\n",
    "    session.add(post)\n",
    "    session.commit()\n",
    "\n",
    "    # 역참조 이용\n",
    "    p = session.get(Post, 1)\n",
    "    for c in p.comments:\n",
    "        print(c.content)"
   ],
   "id": "7400ebdad0575a44",
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2026-06-17 12:03:17,897 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,902 INFO sqlalchemy.engine.Engine INSERT INTO posts (title, content) VALUES (?, ?)\n",
      "2026-06-17 12:03:17,903 INFO sqlalchemy.engine.Engine [generated in 0.00105s] ('LLM 입문', 'LLM이란 무엇인가?')\n",
      "2026-06-17 12:03:17,904 INFO sqlalchemy.engine.Engine INSERT INTO comments (content, post_id) VALUES (?, ?) RETURNING id\n",
      "2026-06-17 12:03:17,906 INFO sqlalchemy.engine.Engine [generated in 0.00008s (insertmanyvalues) 1/2 (ordered; batch not supported)] ('LLM은 언어 모델의 일종입니다.', 2)\n",
      "2026-06-17 12:03:17,906 INFO sqlalchemy.engine.Engine INSERT INTO comments (content, post_id) VALUES (?, ?) RETURNING id\n",
      "2026-06-17 12:03:17,907 INFO sqlalchemy.engine.Engine [insertmanyvalues 2/2 (ordered; batch not supported)] ('좋아요', 2)\n",
      "2026-06-17 12:03:17,908 INFO sqlalchemy.engine.Engine COMMIT\n",
      "2026-06-17 12:03:17,918 INFO sqlalchemy.engine.Engine BEGIN (implicit)\n",
      "2026-06-17 12:03:17,920 INFO sqlalchemy.engine.Engine SELECT posts.id AS posts_id, posts.title AS posts_title, posts.content AS posts_content \n",
      "FROM posts \n",
      "WHERE posts.id = ?\n",
      "2026-06-17 12:03:17,920 INFO sqlalchemy.engine.Engine [generated in 0.00071s] (1,)\n",
      "2026-06-17 12:03:17,923 INFO sqlalchemy.engine.Engine SELECT comments.id AS comments_id, comments.content AS comments_content, comments.post_id AS comments_post_id \n",
      "FROM comments \n",
      "WHERE ? = comments.post_id\n",
      "2026-06-17 12:03:17,924 INFO sqlalchemy.engine.Engine [generated in 0.00067s] (1,)\n",
      "LLM은 언어 모델의 일종입니다.\n",
      "좋아요\n",
      "2026-06-17 12:03:17,925 INFO sqlalchemy.engine.Engine ROLLBACK\n"
     ]
    }
   ],
   "execution_count": 53
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.950832461Z",
     "start_time": "2026-06-17T03:03:17.933917669Z"
    }
   },
   "cell_type": "code",
   "source": [
    "# 💡 이 셀을 실행해야 'Session'이라는 이름이 메모리에 등록됩니다!\n",
    "from sqlalchemy import create_engine\n",
    "from sqlalchemy.orm import sessionmaker\n",
    "\n",
    "engine = create_engine(\"sqlite:///users.db\") # 본인의 engine 설정 코드\n",
    "Session = sessionmaker(bind=engine)"
   ],
   "id": "7d17932707f7f879",
   "outputs": [],
   "execution_count": 54
  },
  {
   "metadata": {
    "ExecuteTime": {
     "end_time": "2026-06-17T03:03:17.968159853Z",
     "start_time": "2026-06-17T03:03:17.952470603Z"
    }
   },
   "cell_type": "code",
   "source": "",
   "id": "48795cdb32be042b",
   "outputs": [],
   "execution_count": 54
  }
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