mysql 数据库的相关操作

Posted 2021-02-08 小金儿

#coding=gbk
#数据库的连接语句
import pymysql
try:
    conn=pymysql.connect(
        host=‘127.0.0.1‘,
        port=3306,
        user=‘root‘,
        passwd=‘root‘,
        charset=‘utf8‘)
    conn.select_db(‘grdb‘)
    cur=conn.cursor()

    cur.execute("")

    cur.close()
    conn.commit()
    conn.close()
except pymysql.Error as e:
    print(e)

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执行多行sql
cur.execute(‘drop table if exists user;‘)
cur.execute("""
    create table user(
    id int(11) default null,
    name varchar(200) default null,
    password varchar(20) default null,
    birthday date default null)engine=innodb default charset=utf8;""")

#insert into 的格式化方式插入数据
sql="insert into user values(%s,%s,%s,%s)"
cur.execute(sql,(6,‘张三666‘,‘221111‘,‘1978-11-15‘))

#测试时批量插入数据
for i in range(100,201):
    s=str(1900+i-100)+‘-3-15‘
    cur.execute(sql,(i,‘张三‘+str(i),‘22111‘,s))

#获取查询数据fetchone
cur.execute("select * from user")
while 1:
    res=cur.fetchone()
    if res==None:
        print(res)
        break

#获取多行数据 cur.fetchmany(2) 获取2条数据
#获取所有数据 cur.fetchall() 获取所有数据
#批量更新 executemany
cur.executemany("update user set name=%s where id=%s",[(‘xiaoli‘,102),(‘xiaobai‘,104)])
后面可以是列表或者元组
cur.executemany("update user set name=%s where id=%s",((‘xiaoli‘,102),(‘xiaobai‘,104)))
如果只有子元素，可以是字典的items()
cur.executemany("update user set name=%s where id=%s",{‘xiaoli2‘:102,‘xiaohei2‘:103,‘xiaobai2‘:104}.items())

#delete多行

cur.executemany("delete from uer where id =%s and name=%s",[(101,‘heihei‘),(104,‘xiaoli‘)])

cur.executemany("delete from uer where id =%s;"[(101,),(104,)])

#事务回滚
conn.rollback()
conn.commit()之前
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