首先说明这个脚本很low，目前水平有限，只能实现使用固定的语法对数据进行增删改查。
需求 a.可进行模糊查询，语法至少支持下面3种: select name,age from staff_table where age > 22 select * from staff_table where dept = "IT" select * from staff_table where enroll_date like "2013" 查到的信息，打印后，最后面还要显示查到的条数 b.可创建新员工纪录，以phone做唯一键，staff_id需自增,语法如下： insert lyndon 24 13811688803 OP 20017-07-01 c.可删除指定员工信息纪录，输入员工id，即可删除，语法如下： delete 删除序号（1-4） d.可修改员工信息，语法如下: UPDATE staff_table SET dept="Market" WHERE where dept = "IT" 注意：以上需求，要充分使用函数，请尽你的最大限度来减少重复代码！
3、测试信息 1,Alex Li,22,13651054608,IT,2013-04-01 2,Jack Wang,30,13304320533,HR,2015-05-03 3,Rain Liu,25,1383235322,Sales,2016-04-22 4,Mack Cao,40,1356145343,HR,2009-03-01
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def mem():
print('''
---------------------------使用说明------------------------------
查询语法：
select name,age from staff_table where age > 22
select * from staff_table where dept = "IT" select * from staff_table where enroll_date like "2013"
创建语法：
insert lyndon 24 13811688803 OP 20017-07-01
删除语法：
delete 序号（序号初始范围1-4）
修改语法：
UPDATE staff_table SET dept="Market" WHERE where dept = "IT"
-----------------水平有限，只能满足以上语法----------------------
【exit】 退出
''')
def check_sql(sql):
parse_sql={
'insert':insert,
'delete':delete,
'update':update,
'select':select
}
sql_l=sql.split(' ')
func=sql_l[0]
res=''
if func in parse_sql:
res=parse_sql[func](sql_l)
return res
# print(sql_l)
def select(sql_l): #['select', 'name,age', 'from', 'staff_table', 'where', 'age', '>', '22']
count=0
if 'age' in sql_l:
with open('info.txt','r',encoding='utf-8') as f_read:
for line in f_read:
info_l=line.split(',')
if int(info_l[2]) > 22:
count+=1
print(line)
if 'dept' in sql_l:
with open('info.txt','r',encoding='utf-8') as f_read:
for line in f_read:
info_l=line.split(',')
if info_l[4] == 'IT':
count+=1
print(line)
if 'like' in sql_l:
with open('info.txt','r',encoding='utf-8') as f_read:
for line in f_read:
info_l=line.split(',')
if info_l[-1].split('-')[0] == '2013':
count += 1
print(line)
print('共查询到 %s 条信息' %count)
def update(sql_l): #['update', 'staff_table', 'set', 'dept="market"', 'where', 'where', 'dept', '=', '"it"']
with open('info.txt', 'r+', encoding='utf-8') as f_read:
lines=f_read.readlines()
with open('info.txt','w',encoding='utf-8') as f_write:
for line in lines:
if 'IT' in line:
line=line.replace('IT','Market',1)
print('信息已更新 %s' %line)
f_write.write(line)
def delete(sql_l):
import os
with open('info.txt', 'r', encoding='utf-8') as f_read,\
open('.info.swap.txt','w+',encoding='utf-8') as f_write:
for line in f_read:
info_l = line.split(',')
if sql_l[1] == info_l[0] :
print('%s 此信息已删除' %line)
else:
f_write.write(line)
os.remove('info.txt')
os.rename('.info.swap.txt','info.txt')
def insert(sql_l): #['insert', 'lyndon', '24', '13811688803', 'op', '20017-07-01']
phone=[]
with open('info.txt', 'r', encoding='utf-8') as f_read:
for line in f_read:
info_l = line.split(',')
count=int(info_l[0])
phone.append(info_l[3])
if sql_l[3] not in phone:
count+=1
sql_l[0]=str(count)
string=','.join(sql_l)
with open('info.txt', 'a', encoding='utf-8') as f:
f.write('\n'+string)
print('%s 信息已插入' %string)
else:
print('此信息已存在')
while True:
print('输入help查看帮助')
sql=input('sql>>>').strip().lower()
if len(sql) == 0:continue
if sql == 'exit':break
if sql == 'help':
mem()
im=check_sql(sql)
本文转自lyndon博客51CTO博客，原文链接http://blog.51cto.com/lyndon/1949364如需转载请自行联系原作者 迟到的栋子 |