黄山门票多少钱,seo综合查询怎么关闭,东海县做网站广告,农产品网络营销渠道游标(cursor)#xff1a;系统为用户开通的一个数据缓冲区#xff0c;用于存放SQL语句执行结果。用户使用的sql会逐一的在游标中获取记录#xff0c;并赋值给主变量#xff0c;交由Python进一步处理#xff0c;一组主变量只能存放一条记录。例题#xff1a;from T1 import…游标(cursor)系统为用户开通的一个数据缓冲区用于存放SQL语句执行结果。用户使用的sql会逐一的在游标中获取记录并赋值给主变量交由Python进一步处理一组主变量只能存放一条记录。例题from T1 importconnect_mysql#----主函数if __name__ __main__:sql select * from test;cnnconnect_mysql()curcnn.cursor()#print (dir(cur))try:cur.execute(sql)#----fetchone 取结果的一行resultcur.fetchone()print(result)#----fetchmany(nu)根据nu数字取结果行数result1cur.fetchmany(3)print(result1)#----fetchall()取全部结果result2cur.fetchall( )#print (22222222)print(result2)cur.close()exceptException as e:cnn.rollback()raiseefinally:cnn.close()执行结果C:\Python27\python.exe E:/untitled/mysql/T2.py(100L,)((200L,), (300L,), (300L,))((40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,))Process finished with exit code 0图中语句依次执行由于数据只有四条并且三者语句一起执行所以执行ftechone取走一条执行fetchmany(3)取走三条剩下以为空所以fetchall()只能取空。执行多条语句from T1 import connect_mysql#----主函数if __name__ __main__:sql select * from test;sq11insert into test(id) VALUES (%s);#----将函数组合成多个listLis[]for i in xrange(40,50):----此处表示批量执行语句的格式为sql语句参数将一列参数(类型为list)逐个传入sql1中。Lis.append([str(i)])# print (Lis)cnnconnect_mysql()cur cnn.cursor()try:cur.executemany(sq11,Lis) -----注意二者的执行顺序应该先插入后再查询否则查询结果为空。cur.execute(sql)#----fetchall()取全部结果result2cur.fetchall( )print (result2)cur.close()cnn.commit()-------执行语句后需要执行提交否则数据库内无法生效。except Exception as e:cnn.rollback()raise efinally:cnn.close()执行结果C:\Python27\python.exe E:/untitled/mysql/T2.py((100L,), (200L,), (300L,), (300L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,), (40L,), (41L,), (42L,), (43L,), (44L,), (45L,), (46L,), (47L,), (48L,), (49L,))Process finished with exit code 0
