import pymysql.cursors

# 连接数据库
connect = pymysql.Connect(
    host=‘192.168.0.250‘,
    port=3306,
    user=‘root‘,
    passwd=‘123456‘,
    db=‘anec‘,
    charset=‘utf8‘
)

# 获取游标
cursor = connect.cursor()

# 创建数据表,执行SQL语句
create_table = """
create table t1(
id int ,
name varchar(255)
)
"""
cursor.execute(create_table)


# 添加数据,并需要commit提交
add_t1 = """
insert into t1(id,name) values(1,‘小红‘),(2,‘小美‘);"""
cursor.execute(add_t1)
connect.commit()

# 格式化,插入单条数据
sql = ‘insert into userinfo (user,pwd) values (%s,%s);‘
name = ‘wuli‘
pwd = ‘123456789‘
cursor.execute(sql, [name, pwd])
connect.commit()

# 获取最新的那一条数据的ID
last_id = cursor.lastrowid
print("最后一条数据的ID是:", last_id)

# 定义要执行的sql语句,拼接并执行sql语句
sql = ‘insert into userinfo(user,pwd) values(%s,%s);‘
data = [
    (‘july‘, ‘147‘),
    (‘june‘, ‘258‘),
    (‘marin‘, ‘369‘)]
cursor.executemany(sql, data)

# 删除数据,拼接并执行SQL语句
sql = "delete from userinfo where user=%s;"
name = "june"
cursor.execute(sql, [name])
connect.commit()


# 拼接并执行SQL语句,修改数据
sql = "update userinfo set pwd=%s where user=%s;"
cursor.execute(sql, ["july", "july"])
connect.commit()

# 获取一个光标,定义将要执行的sql语句,拼接并执行sql语句,取到查询结果
cursor = connect.cursor(cursor=pymysql.cursors.DictCursor)  # 返回字典数据类型
sql = ‘select user,pwd from userinfo;‘
cursor.execute(sql)
ret1 = cursor.fetchone()  # 取一条
ret2 = cursor.fetchmany(3)  # 取三条
ret3 = cursor.fetchone()  # 取一条

# 可以获取指定数量的数据
cursor.fetchmany(3)
# 光标按绝对位置移动1
cursor.scroll(1, mode="absolute")
# 光标按照相对位置(当前位置)移动1
cursor.scroll(1, mode="relative")


# #数据回滚
# try:
#     # 拼接并执行SQL语句
#     cursor.execute(sql1, [user, pwd])
#     cursor.execute(sql2, [id, hobby])  # 报错的SQL语句
#     # 涉及写操作注意要提交
#     connect.commit()
# except Exception as e:
#     print(str(e))
#     # 有异常就回滚
#     connect.rollback()

# 关闭光标对象
cursor.close()

# 关闭数据库连接
connect.close()