需求如下
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
查到的信息，打印后，最后面还要显示查到的条数
可创建新员工纪录，以phone做唯一键，staff_id需自增
可删除指定员工信息纪录，输入员工id，即可删除
可修改员工信息，语法如下:
UPDATE staff_table SET dept="Market" where dept = "IT"
1 #!/usr/bin/env python 2 #-*- coding:utf-8 -*- 3 # @Time : 2017/9/22 14:30 4 # @Author : lichuan 5 # @File : lianxi.py 6 7 8 9 import os 10 11 def where(sql): 12 # sql='age > 22' 13 lines='' 14 s=sql.split() 15 index=title.index(str(s[0]).strip()) 16 with open('info.txt',encoding='utf-8') as read_f: 17 for line in read_f: 18 l=line.split(',') 19 # print(str(l[index])) 20 # print(str(s[-1]).strip().strip('"').strip("'")) 21 if 'like' in sql and str(s[-1]).strip('"').strip("'") in str(l[index]): 22 lines=lines+line 23 elif '>' in sql and str(s[-1]).strip("'").strip('"').isdigit() and int(l[index]) > int(str(s[-1]).strip("'").strip('"')): 24 lines = lines + line 25 elif '<' in sql and s[-1].isdigit() and int(l[index]) < int(s[-1]): 26 lines = lines + line 27 elif '=' in sql and str(l[index]) == str(s[-1]).strip().strip('"').strip("'"): 28 lines = lines + line 29 # print("str(l[index]).upper() is %s" %str(l[index]).upper()) 30 # print("str(s[-1]) is %s" %str(s[-1])) 31 return lines 32 33 34 def tablename_check(fun): 35 def wrapper(sql): 36 # sql='' 37 check=sql.split() 38 # print(check) 39 # print('staff_table' in check) 40 if 'staff_table' in check: 41 fun(sql) 42 else: 43 print("staff_tab is needed!") 44 return 1 45 return wrapper 46 47 48 def from_check(fun): 49 def inner_check(sql): 50 s=sql.lower().split() 51 if "from" not in s: 52 print("no from in the sql!") 53 return 1 54 for item in s: 55 if item == "from": 56 i=s.index("from")+1 57 if s[i] == "staff_table": 58 fun(sql) 59 else: 60 print("table name is wrong! table name is staff_table") 61 return inner_check 62 63 def where_check(fun): 64 def inner_check(sql): 65 s1=str(sql.lower().split('where')[1]).split() 66 if len(s1) != 3: 67 print("%s is wrong" % str(s1)) 68 return 1 69 s=sql.lower() 70 if "where" not in s: 71 print("no where in the sql!") 72 fun(sql) 73 else: 74 i=str(s.split('where')[1]).split()[0] 75 i=str(i).strip() 76 if i in title : 77 fun(sql) 78 else: 79 print("where %s is wrong! " %str(i)) 80 return inner_check 81 82 # with open("info.txt",encoding='utf-8') as read_f: 83 # for line in read_f: 84 # d=line.split(",") 85 86 def insert_check(fun): 87 def inner_check(sql): 88 # sql="insert into staff_table (name,age,phone,dept,enroll_date) values ('lit','18','13523081939','IT','2009-03-01')" 89 # s='' 90 sl=sql.split() 91 if 'values' not in sl and 'values'.upper() not in sl: 92 print("values in needed") 93 return 1 94 if "insert into staff_table" not in sql and "insert into staff_table".upper() not in sql: 95 print("no insert into staff_table in the sql!") 96 return 1 97 else: 98 keys=str(sql.split(')')[0].split('(')[1]).split(',') 99 for k in title: 100 if k not in keys and k != 'staff_id': 101 print("%s is not defined" %k) 102 return 1 103 fun(sql) 104 return inner_check 105 106 @where_check 107 @from_check 108 def select(sql): 109 ''' select staff_id,name,age,phone,dept,enroll_date from staff_table where name = "Alex"''' 110 # str1='' 111 # sql='' 112 sql=sql.replace(';','') 113 i=sql.find("from") 114 list=sql[7:i].strip().split(",") 115 # print(list) 116 s=set(list) 117 count=0 118 lines='' 119 if list[0] == '*': 120 if 'where' in sql: 121 wh=sql.split('where') 122 lines=where(wh[1]) 123 # print(lines) 124 else: 125 with open('info.txt',encoding='utf-8') as read_f: 126 for line in read_f: 127 lines=lines+line 128 # print(lines) 129 for line in lines.split('\n'): 130 if line != '': 131 print(line) 132 # print('**********************************') 133 count+=1 134 print("\n%d 行被选择" %count) 135 elif s.issubset(set(title)): 136 if 'where' in sql.lower(): 137 wh=sql.split('where') 138 lines=where(wh[1]) 139 # print(lines) 140 else: 141 with open('info.txt',encoding='utf-8') as read_f: 142 for line in read_f: 143 lines=lines+line 144 # print(lines) 145 for line in lines.split('\n'): 146 if line != '': 147 new_line='' 148 l=line.split(',') 149 sub=sql_list[1].split(',') 150 # print('sub is '+str(sub)) 151 for sl in sub: 152 i=title.index(sl) 153 # print('i is '+str(i)) 154 new_line+=str(l[i])+',' 155 print(new_line.strip(',')) 156 # print('**********************************') 157 count+=1 158 print("\n%d 行被选择" %count) 159 else: 160 print(','.join(list)+" is wrong") 161 return sql 162 163 @tablename_check 164 @where_check 165 def update(sql): 166 ''' 167 UPDATE staff_table SET dept="Market" where dept = "IT" 168 ''' 169 s=sql.split() 170 171 if 'where' not in s and 'WHERE' not in s: 172 print("no where in the sql,try again") 173 return 1 174 if 'SET' not in s and 'set' not in s: 175 print("no set in the sql,try again") 176 return 1 177 178 s1 = sql.split('where')[1] 179 # print("s1"+s1) 180 wh=where(str(s1)) 181 # print('wh'+wh) 182 lines='' 183 value=str(str(sql.split('where')[0]).split('=')[1]).strip().strip('"').strip("'") 184 with open('info.txt','r',encoding='utf-8') as read_f, open('info.txt.swap','w',encoding='utf-8') as write_f: 185 for f in read_f: 186 if f not in wh: 187 lines=lines+f 188 else: 189 for i in title: 190 # print(i) 191 if i in sql.lower(): 192 old=f.split(',')[title.index(i)] 193 # print("old"+old) 194 f=f.replace(old,value) 195 lines=lines+f 196 # print(lines) 197 write_f.write(lines.strip('\n')) 198 read_f.close() 199 write_f.close() 200 os.remove('info.txt') 201 os.rename('info.txt.swap', 'info.txt') 202 203 204 @tablename_check 205 @insert_check 206 def insert(sql): 207 keys=sql.split(')')[0].split('(')[1].split(',') 208 # print(keys) 209 values=sql.split('(')[2].split(')')[0].split(',') 210 # print(values) 211 line = '' 212 if sql.split()[2] != 'staff_table': 213 print('table name is wrong,the right name is staff_table') 214 elif sql.split(): 215 with open('info.txt','r+',encoding='utf-8') as read_f: 216 r=read_f.readlines() 217 staff_id=int(r[-1].split(',')[0])+1 218 name=values[keys.index('name')].replace("'",'') 219 age=values[keys.index('age')].replace("'",'') 220 phone=values[keys.index('phone')].replace("'",'') 221 dept=values[keys.index('dept')].replace("'",'') 222 enroll_date=values[keys.index('enroll_date')].replace("'",'') 223 line="\n%d,%s,%s,%s,%s,%s" %(staff_id,name,age,phone,dept,enroll_date) 224 l=[i for i in r if str(phone)==str(i.split(',')[3])] 225 # print(l) 226 if l: 227 print('%s is already in use.' % phone) 228 else: 229 read_f.write(line) 230 231 232 @where_check 233 @from_check 234 @tablename_check 235 def delete(sql): 236 # sql='delete from staff_table where id=王伟' 237 # print(sql) 238 if 'where' not in sql and 'WHERE' not in sql: 239 print("no where in the sql,try again") 240 return 1 241 s=str(sql.split('where')[1]) 242 wh=where(s) 243 print(wh) 244 lines='' 245 with open('info.txt','r',encoding='utf-8') as read_f,open('info.txt.swap','w',encoding='utf-8') as write_f: 246 # l=str(read_f.readlines()).replace('wh','') 247 # write_f.write(l) 248 for f in read_f: 249 if f not in wh: 250 lines=lines+f 251 # print(lines) 252 write_f.write(lines.strip('\n')) 253 read_f.close() 254 write_f.close() 255 os.remove('info.txt') 256 os.rename('info.txt.swap','info.txt') 257 258 259 260 title=['staff_id','name','age','phone','dept','enroll_date'] 261 262 func={ 263 "select":select, 264 "update":update, 265 "insert":insert, 266 "delete":delete 267 } 268 269 270 while True: 271 sql = input("q==quit;input your sql:").strip() 272 if sql.strip().lower() == 'q': 273 break 274 sql_list = sql.split() 275 # print(sql_list) 276 if sql_list[0].lower() in func: 277 func[str(sql_list[0]).lower()](sql) 278 else: 279 print("wrong,please input your sql again!")