浅析python连接数据库的重要事项

import pymysql

conn = pymysql.connect(
  host="",
  user="jxz",
  password="",
  db="jxz",
  port=3306,
  charset="utf8",
  autocommit=True

for line in cursor:#表数据比较多的时候就用它
  print(line)
#还有其他的间接的方式
# result = cursor.fetchmany(5) #获取n条
#cursor.execute("select * from students limit 5;")

cursor = conn.cursor(pymysql.cursors.DictCursor) #建立游标

import pymysql
conn=pymysql.connect(host='',
        user='jxz',
        password='',
        db='jxz',
        port=3306,
        autocommit=True,
        charset='utf8')#链接数据库
cursor=conn.cursor()#游标
#查看当前所有的表
#cursor.execute('create table lmmlmm(num int,str varchar (20));')
cursor.execute('insert into lmmlmm (num,str)values("1","limiaomiao");')
conn.commit()
result=cursor.fetchall()
cursor.close()
conn.close()
print(result)

import pymysql

mysql_info = pymysql.connect(
  host="",
  user="jxz",
  password="",
  db="jxz",
  port=3306,
  charset="utf8",
  autocommit=True
)#连接数据库
##**后面只能是字典，且能够转换成key，value
def execute_sql(sql,more=False,db_info=None):
 # select *from user where id=1；
  if db_info:
    conn=pymysql.connect(**db_info)
  else:
    conn=pymysql.connect(**mysql_info)