python基礎之操作數據庫(pymysql)操作

import pymysql
import datetime

#安裝 pip install pymysql
"""
1、連接本地數據庫
2、建立游標
3、創建表
4、插入表數據、查詢表數據、更新表數據、刪除表數據
"""
#連接本地數據庫
db = pymysql.connect(
    host = "localhost", #數據庫的主機地址
    user = "root",      #數據庫登錄的用戶名
    passwd = "123456",  #數據庫登錄的密碼
    database = "test"   #數據庫名字
)

#創建游標
cursor = db.cursor()

def create_table():
    #如果存在student表，則刪除
    cursor.execute("DROP TABLE IF EXISTS student")

    #創建student表 --元組
    sql = """
        create table student(
        id int not null,
        name char(10),
        age int,
        address char(20),
        create_time datetime)
    """

    try:
        # 執行SQL語句
        cursor.execute(sql)
        print("創建數據庫成功")
    except Exception as e:
        print("創建數據庫失敗：case%s"%e)
    finally:
        pass
        #關閉游標連接
        # cursor.close()
        # 關閉數據庫連接
        # db.close()


def insert_into():
    #批量插入數據
    sql = "INSERT INTO  student VALUES(%s,%s,%s,%s,%s)"
    params = [
        (1,"小王",23,"深圳",datetime.datetime.now()),
        (2,"小劉",24,"深圳",datetime.datetime.now()),
        (3,"小宋",25,"深圳",datetime.datetime.now())
    ]

    try:
        # 執行SQL語句 批量插入用executemany
        cursor.executemany(sql,params)
        # 提交到數據庫執行
        db.commit()
        print("有",cursor.rowcount,"插入數據成功")
    except Exception as e:
        print("插入數據失敗：case%s"%e)
        # 如果發生錯誤則回滾
        db.rollback()
    finally:
        pass
        # 關閉游標連接
        # cursor.close()
        # 關閉數據庫連接
        # db.close()

def update_Set():
    #SQL語句更新數據
    sql = """UPDATE student SET address = '東莞' WHERE ID = %s"""%(2)

    try:
        # 執行SQL語句
        cursor.execute(sql)
        # 提交到數據庫執行
        db.commit()
        print("有",cursor.rowcount,"更新數據成功")

    except Exception as e:
        print("數據更新出錯：case%s"%e)
        #發生錯誤是回滾
        db.rollback()

    finally:
        pass
        # 關閉游標連接
        # cursor.close()
        # 關閉數據庫連接
        # db.close()


def select_form():
    # SQL 查詢語句 --條件查詢
    sql = "SELECT * FROM student WHERE ID = %s"%(2)

    try:
        # 執行SQL語句
        cursor.execute(sql)
        # 獲取所有記錄列表 fetchall
        results = cursor.fetchall()
        for row in results:
            id = row[0]
            name = row[1]
            age = row[2]
            address = row[3]
            create_time = row[4]
            print("id=%s,name=%s,age=%s,address=%s,create_time=%s"%\
                  (id,name,age,address,create_time))

    except Exception as e:
        print("查詢出錯：case%s"%e)

    finally:
        # 關閉游標連接
        cursor.close()
        # 關閉數據庫連接
        db.close()

def exit():
    """退出系統"""
    import sys
    sys.exit()
    print("退出系統")

def main():
    while True:
        choice = int(input("請選擇下面的數字:\n"
                           "1.創建表\n"
                           "2.插入數據\n"
                           "3.更新數據\n"
                           "4.查詢數據\n"
                           "5.退出系統\n"
                           ))
        if choice == 1:
            create_table()
        elif choice == 2:
            insert_into()
        elif choice == 3:
            update_Set()
        elif choice == 4:
            select_form()
        else:
            exit()

if __name__ == "__main__":
    main()