pymysql的操作记录

import pymysql
import datetime

def db_connect():
    db = pymysql.connect(host="localhost",user="root",password="root",db="python")
    #创建游标对象
    cursor = db.cursor()
    #游标指向执行
    cursor.execute("SELECT VERSION()")
    #获取结果，获取单条数据，fetchall获取多条
    data = cursor.fetchone()
    print(f"Darabase version : {data[0]}")
    print(db)
    db.close()

def create_table():
    db = pymysql.connect(host="localhost",user="root",password="root",db="python")

    #2、创建游标对象
    cursor = db.cursor()

    #3、创建sql语句
    sql = """
        create table employee(
            first_name varchar(20) not null,
            last_name varchar(20) not null,
            age int,
            sex varchar(1),
            income float, -- 如果是货币类型则不要使用float
            create_time datetime       
        );
    """
    #4、执行sql语句
    try:
        cursor.execute(sql)
        print("执行成功")
    except:
        print("执行失败")
    finally:
        db.close()

def inser_data():
    db = pymysql.connect(host="localhost",user="root",password="root",db="python")
    cursor = db.cursor()

    sql = """
        insert into employee(first_name,last_name,age,sex,income,create_time) values
        ('%s','%s','%d','%s','%d','%s') 
    """ % ('小','哪',18,'女',12000,datetime.datetime.now())
    try:
        #执行插入的时候自动开启了事务
        cursor.execute(sql)
        db.commit()
        print("插入成功")
    #except:
        #print("插入失败")
    finally:
        db.close()
        print("插入执行完成")

#数据查询
def select_data():
    db = pymysql.connect(host="localhost",user="root",password="root",db="python")
    cursor = db.cursor()
    sql = 'select * from employee where income > %d' % 10000

    try:
        cursor.execute(sql)
        print("查询成功")
        #获取数据,fecthall返回的是一个大元组，元组中的元素也是元组
        res = cursor.fetchall()
        print(res[0])
        #提取元素
        for r in res:
            first_name = r[0]
            last_name = r[1]
            age = r[2]
            sex = r[3]
            income = r[4]
            create_time = r[5]
        print(f'')
    except:
        print("查询失败")
    finally:
        db.close()


def main():
    select_data()

main()