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()