import pymysql
from pymysql.cursors import DictCursor

conn = pymysql.connect(host='localhost', user='root', password='123456', database='day1', port=3306,
cursorclass=DictCursor, connect_timeout=3)
cursor = conn.cursor()

【直接用sql语句进行增删改查】

增加

sql2 ='insert into student(gender,sname,class_id) values("男","abc",1)'

cursor.execute(sql2)

conn.commit()

修改

sql3 ='update student set sname="bcd" where sid=1'

cursor.execute(sql3)

conn.commit()

删除

sql4 ='delete from student where sid=17'

cursor.execute(sql4)

conn.commit()

【用sql语句占位符进行增删改查】

增加

sql2 ='insert into student(gender,sname,class_id) values(%s,%s,%s)'

cursor.execute(sql2,('男','edf',2))

conn.commit()

修改

sql3 ='update student set sname=%s where sid=%s'

cursor.execute(sql3,('abd',1))

conn.commit()

删除

sql4 ='delete from student where sid=%s'

cursor.execute(sql4,'18')

conn.commit()

【用sql语句关键字占位符进行增删改查】

增加

sql2 = 'insert into student(gender,sname,class_id) values(%(gender)s,%(sname)s,%(class_id)s)'

cursor.execute(sql2, {'gender': '男', "sname": 'edf', "class_id": 2})

conn.commit()

修改

sql3 ='update student set sname=%(sname)s where sid=%(sid)s'

cursor.execute(sql3,{'sname':'亲爱',"sid":19})

conn.commit()

删除

sql4 ='delete from student where sid=%(sid)s'

cursor.execute(sql4,{"sid":'19'})

conn.commit()

sql = 'select * from student'
cursor.execute(sql)
result = cursor.fetchall()

print(conn)
print(result)