1 # !/usr/bin/env python3
2 # _*_coding:utf-8_*_
3
4
5 def help_sql(cmd):
6 if cmd in func_dic.keys():
7 print(‘{} usage:\n ‘.format(cmd))
8 if cmd == ‘select‘:
9 print("\tselect * from staff_table;")
10 print("\tselect name,age from staff_table where age > 22;")
11 print("\tselect * from staff_table where dept = \"IT\";")
12 print("\tselect * from staff_table where date like \"2013\";")
13 elif cmd == ‘insert‘:
14 print("\tinsert talbe (Alex Li,22,136510546011,IT,2013-04-01);")
15 elif cmd == "update":
16 print("\tupdate staff_table set dept = \"Market\" where dept = \"IT\";")
17 elif cmd == "delete":
18 print("\tdelete table 5;")
19 else:
20 print(‘your input ERROR!‘)
21 return
22
23
24 def input_sql():
25 ‘‘‘
26 接受用户输入，做一些判断，转化 list 并一起返回。
27 :return:sql
28 ‘‘‘
29 exit_flag = False
30 while exit_flag is not True:
31 sql = input(‘sql > ‘).strip()
32 sql_list = sql_to_list(sql)
33 if sql.startswith(‘help‘):
34 cmd = sql_list[1]
35 help_sql(cmd)
36 continue
37 elif sql == ‘q‘ or sql == ‘quit‘ or sql == ‘Q‘ or sql == ‘QUIT‘ or sql == ‘exit‘ or sql == ‘EXIT‘:
38 print(‘已退出程序！‘)
39 exit(1)
40 elif len(sql_list) == 0:
41 continue
42 elif len(sql_list) < 2:
43 continue
44 elif not (sql.startswith(‘select‘) or sql.startswith(‘insert‘) or sql.startswith(‘update‘) or sql.startswith(
45 ‘delete‘)):
46 continue
47 exit_flag = True
48 return sql
49
50
51 def delete_quotes(str):
52 ‘‘‘
53 删掉用户输入的条件值中带双引号。单引号不用去
54 :param str:
55 :return:
56 ‘‘‘
57 if ‘"‘ in str:
58 str = str.strip(‘"‘)
59 return str
60
61
62 def sql_to_list(sql, delimiter=‘ ‘):
63 ‘‘‘
64 将用户输入的字符串转化为列表的形式，
65 :param sql:
66 :param delimiter:
67 :return:
68 ‘‘‘
69 tmp_list = filter(None, sql.split(delimiter))
70 sql_list = [item for item in tmp_list]
71 return sql_list
72
73
74 def analyze(sql, table):
75 ‘‘‘
76 分析用户输入sql 语句，作用：
77 1.拿到 cmd
78 2.判断表是否存在
79 3.返回命令和要操作的表
80 :param sql:
81 :param sql_list:
82 :param table:
83 :return:
84 ‘‘‘
85 sql_list = sql_to_list(sql)
86 cmd = sql_list[0]
87 if sql.startswith(‘select‘):
88 sql_table = sql_list[3]
89 if sql_table in table:
90 return cmd, sql_table
91 else:
92 return False
93 if sql.startswith(‘insert‘) or sql.startswith(‘update‘) or sql.startswith(‘delete‘):
94 sql_table = sql_list[1]
95 if sql_table in table:
96 return cmd, sql_table
97 else:
98 return False
99
100 # input_list = sql_to_list(sql)
101 # cmd = input_list[0]
102 # input_table = input_list[3]
103 # if input_table in table:
104 # return cmd, input_table
105 # else:
106 # return False
107
108
109 def file_to_data(sql_table):
110 ‘‘‘
111 将文件中的数据读到内存中，以遍读取。这个方法是把所有的数据上来就读进内存中。
112 :param sql_table:
113 :return:
114 ‘‘‘
115 n = 0
116 struct_list = []
117 data_list = []
118 with open(sql_table, ‘r‘, encoding=‘utf-8‘) as f:
119 for line in f:
120 if n == 0:
121 # line = line.strip(‘\n‘)
122 struct_list = line.strip(‘\n‘).split(‘,‘)
123 else:
124 # line = line.strip(‘\n‘)
125 line_list = line.strip(‘\n‘).split(‘,‘)
126 data_list.append(line_list)
127 n += 1
128 return struct_list, data_list
129
130
131 def data_to_file(struct_list, data_list, table):
132 ‘‘‘
133 将内存中的数据写入到文件里
134 :param struct_list:
135 :param data_list:
136 :param table:
137 :return:
138 ‘‘‘
139 with open(table, ‘w‘, encoding=‘utf-8‘) as f:
140 f.write(‘,‘.join(struct_list) + ‘\n‘)
141 for sub_list in data_list:
142 f.write(‘,‘.join(sub_list) + ‘\n‘)
143 print(‘Write Done!‘)
144
145
146 def get_cloum_number(colum_name, struct_list):
147 ‘‘‘
148 获取列所对应的索引，然后用这个索引在数据项里面取值
149 :param colum_name:
150 :param struct_list:
151 :return:
152 ‘‘‘
153 colum_number = struct_list.index(colum_name)
154 # print(colum_number)
155 return colum_number
156
157
158 def auto_increament_id(data_list):
159 ‘‘‘
160 insert 数据项时，获取新的 id
161 :param data_list:
162 :return:
163 ‘‘‘
164 current_max_id = int(data_list[-1][0])
165 new_index_id = current_max_id + 1
166 return new_index_id
167
168
169 # 增删改查阶段
170 def select(sql, struct_list, data_list, sql_table):
171 sql_list = sql_to_list(sql)
172 select_colum = sql_list[1].split(‘,‘)
173 all_cloum = False
174 all_line = False
175 if ‘*‘ in select_colum: # 判断输出那些列
176 all_cloum = True
177 else:
178 cloum_numbers_list = []
179 for cloum_name in select_colum:
180 number = get_cloum_number(cloum_name, struct_list)
181 cloum_numbers_list.append(number)
182
183 # 关键字过滤
184 select_row = [] # 过滤后的行
185 if ‘where‘ in sql:
186 condition_column_name = sql_list[5]
187 condition_str = sql_list[6]
188 condition_value = sql_list[7]
189 condition_value = delete_quotes(condition_value)
190 condition_column_number = get_cloum_number(condition_column_name, struct_list)
191
192 if condition_str == ‘=‘:
193 for line in data_list:
194 if line[condition_column_number] == condition_value:
195 select_row.append(line)
196 if condition_str == ‘>‘:
197 for line in data_list:
198 if line[condition_column_number] > condition_value:
199 select_row.append(line)
200 if condition_str == ‘>=‘:
201 for line in data_list:
202 if line[condition_column_number] >= condition_value:
203 select_row.append(line)
204 if condition_str == ‘<‘:
205 for line in data_list:
206 if line[condition_column_number] < condition_value:
207 select_row.append(line)
208 if condition_str == ‘<=‘:
209 for line in data_list:
210 if line[condition_column_number] <= condition_value:
211 select_row.append(line)
212 if condition_str == ‘like‘:
213 for line in data_list:
214 if condition_value in line[condition_column_number]:
215 select_row.append(line)
216 else:
217 all_line = True
218 select_row = data_list
219
220 # 输出查询的结果
221 print(‘select result:‘)
222 print(‘#‘.center(80, ‘#‘))
223 print(‘\033[1;31;1m{}\033[0m rows in set‘.format(len(select_row)))
224 if all_cloum is True:
225 print(‘\033[1;34;1m{:<13} {:<13} {:<13} {:<13} {:<13} {:<13}\033[0m‘.format(*struct_list))
226 for line in select_row:
227 print(‘{:<13} {:<13} {:<13} {:<13} {:<13} {:<13}‘.format(*line))
228 # print(‘\t‘)
229 else:
230 len_num = len(select_colum)
231 format_str1 = ‘\033[1;34;1m{:13}\033[0m‘ * len_num
232 format_str2 = ‘{:13}‘ * len_num
233 print(format_str1.format(*select_colum))
234 for line in select_row:
235 row_list = []
236 for s in cloum_numbers_list:
237 row_list.append(line[s])
238 print(format_str2.format(*row_list))
239 print(‘#‘.center(80, ‘#‘))
240 return True
241
242
243 def insert(sql, struct_list, data_list, sql_table):
244 ‘‘‘
245 insert sql : insert user_info.json (Liusong Fan,22,13143236545,IT,2015-09-09)
246 insert sql : insert user_info.json (Liusong Fan,22,13487654567,IT,2015-09-09)
247 电话号码作为主键。
248 目前只支持插入全部数据项。
249 手机号码必须是11位
250 :param sql:
251 :param struct_list:
252 :param data_list:
253 :return:
254 ‘‘‘
255 tmp_insert = sql_to_list(sql.strip().strip(‘insert‘).strip(), ‘(‘)
256 insert_table = tmp_insert[0].strip()
257 insert_info = (tmp_insert[1].strip(‘(‘).strip(‘)‘))
258 insert_list = insert_info.split(‘,‘)
259
260 phone_number = insert_list[2]
261 if len(phone_number) != 11:
262 print("Phone number wrong(11 numbers), can‘t insert")
263 return False
264 phone_exist = False
265 for item in data_list:
266 if phone_number == item[3]:
267 phone_exist = True
268 if phone_exist:
269 print("Phone number is exist, can‘t insert")
270 return False
271 else:
272 new_index_id = auto_increament_id(data_list)
273 insert_list.insert(0, str(new_index_id))
274 data_list.append(insert_list)
275 data_to_file(struct_list, data_list, insert_table)
276
277
278 def delete(sql, struct_list, data_list, sql_table):
279 ‘‘‘
280 # delete table 5
281 使用按 id 号删除
282 :param ql:
283 :param struct_list:
284 :param data_list:
285 :param sql_table:
286 :return:
287 ‘‘‘
288 delete_flag = False
289 delete_list = sql_to_list(sql.strip())
290 delete_index_id = delete_list[2]
291 for item in data_list:
292 if delete_index_id == item[0]:
293 delete_flag = True
294 data_list.remove(item)
295 if not delete_flag:
296 print("ERROE:The delete id is not exist,can‘t delete")
297 return True
298 else:
299 data_to_file(struct_list, data_list, sql_table)
300
301
302 def update(sql, struct_list, data_list, sql_table):
303 ‘‘‘
304 update user_info.json set dept = "Market" where id = "1"
305 set 的值和 where 的值要加"号
306 id 是自增的不允许修改，phone 是主键，不允许重复
307 set 和 where 只支持 =
308 :param sql:
309 :param struct_list:
310 :param data_list:
311 :param sql_table:
312 :return:
313 ‘‘‘
314 update_list = sql_to_list(sql)
315 set_flag = update_list[2]
316 modify_column = update_list[3]
317 equal_flag = update_list[4]
318 modify_value = update_list[5]
319 modify_value = delete_quotes(modify_value)
320 where_flag = update_list[6]
321 condition_column = update_list[7]
322 condition_str = update_list[8]
323 condition_value = update_list[9]
324 condition_value = delete_quotes(condition_value)
325 modify_column_number = get_cloum_number(modify_column, struct_list)
326 condition_column_number = get_cloum_number(condition_column, struct_list)
327
328 modify_flag = False
329 if modify_column == ‘id‘:
330 print("ERROR: you can‘t modify id column value")
331 return False
332 else:
333 if set_flag == ‘set‘ and equal_flag == ‘=‘ and where_flag == ‘where‘ and condition_str == ‘=‘:
334 phone_exists = False
335 phone_number = modify_value
336 for item in data_list:
337 if phone_number == item[3]:
338 phone_exists = True
339 if phone_exists:
340 print("ERROR: you input phone number is exists, can‘t update")
341 return False
342 for d_list in data_list:
343 if d_list[condition_column_number] == condition_value:
344 d_list[modify_column_number] = modify_value
345 modify_flag = True
346 if modify_flag:
347 data_to_file(struct_list, data_list, sql_table)
348 else:
349 print("ERROR: no match records")
350 else:
351 print("ERROR: you upate sql error, please input ‘help update‘ get help")
352
353
354 func_dic = {
355 ‘‘‘
356 要操作的数据类型
357 ‘‘‘
358 ‘select‘: select,
359 ‘update‘: update,
360 ‘insert‘: insert,
361 ‘delete‘: delete,
362 }
363
364
365 def main():
366 exit_flag = False
367 table = [‘user_info.json‘]
368 print(‘-‘.center(60, ‘-‘))
369 print(‘Please input【help [select/update/insert/delete] to get help.‘)
370 print(‘-‘.center(60, ‘-‘))
371 while exit_flag is not True:
372 sql = input_sql()
373 res = analyze(sql, table)
374 if not res:
375 print(‘ERROR: your input sql table is not exists!‘)
376 continue
377 else:
378 cmd = res[0]
379 sql_table = res[1]
380 struct_list, data_list = file_to_data(sql_table)
381 if cmd in func_dic.keys():
382 res = func_dic[cmd](sql, struct_list, data_list, sql_table)
383 if not res:
384 continue
385 else:
386 print(‘ERROR: your command!‘)
387
388
389 if __name__ == ‘__main__‘:
390 main()
原文地址：https://www.cnblogs.com/lincappu/p/8143871.html
时间： 2024-10-24 07:02:10