C 使用与文件B共享的元素(外键)访问文件A中的数据
我有一个car.txt文件和一个reservation.txt文件。这两个文件都有一个保留号(Rxxx) 我想使用reservation.txt中的预订号打印带有相应预订号的汽车详细信息。或者更准确地说,我正试图找到在任何给定日期可用的所有汽车的详细信息 car.txt: (从左到右:保留、carID、carYOM、carMake、carModel、carFuel、分类) reservation.txt: (从左到右:reservationID、customerID、reservationStartDate、reservationStartTime、reservationEndDate、reservationEndTime) 如果我输入任何日期,它只会确定输入的日期是否在预订开始日期和结束日期之间。“所有的车都有” 但是,如果我输入2012年2月13日,它会打印7次“cars.txt中没有匹配的resID” 有关守则:C 使用与文件B共享的元素(外键)访问文件A中的数据,c,file,foreign-keys,structure,C,File,Foreign Keys,Structure,我有一个car.txt文件和一个reservation.txt文件。这两个文件都有一个保留号(Rxxx) 我想使用reservation.txt中的预订号打印带有相应预订号的汽车详细信息。或者更准确地说,我正试图找到在任何给定日期可用的所有汽车的详细信息 car.txt: (从左到右:保留、carID、carYOM、carMake、carModel、carFuel、分类) reservation.txt: (从左到右:reservationID、customerID、reservationSta
#include <stdio.h>
#include <string.h>
#define MAX_CAR 100
#define MAX_RES 100
int main(){
typedef struct{ //car struct
char reservationID[20];
char carID[20];
char carYOM[20];
char carMake[20];
char carModel[50];
char carFuel[20];
char catagory[20];
} car_t;
typedef struct{ //res struct
char reservationID[20];
char customerID[20];
char reservationStartDate[20];
char reservationStartTime[20];
char reservationEndDate[50];
char reservationEndTime[20];
} res_t;
car_t car[MAX_CAR]; //car array
res_t reservation[MAX_RES]; //res array
FILE *carHandle;
FILE *resHandle;
char line[100];
char *item;
int rescount = 0;
int carcount =0;
int k;
int i;
int option;
char choice[20];
resHandle = fopen("reservation.txt","r");
while (fgets(line, 99, resHandle)){ //cut up the reservation file line by line and put the bits into the res array.
item = strtok(line,";");
strcpy(reservation[rescount].reservationID,item);
item = strtok(NULL,";");
strcpy(reservation[rescount].customerID,item);
item = strtok(NULL,";");
strcpy(reservation[rescount].reservationStartDate,item);
item = strtok(NULL,";");
strcpy(reservation[rescount].reservationStartTime,item);
item = strtok(NULL,";");
strcpy(reservation[rescount].reservationEndDate,item);
item = strtok(NULL,"\n");
strcpy(reservation[rescount].reservationEndTime,item);
rescount++;
}
fclose(resHandle);
carHandle = fopen("car.txt","r");
while (fgets(line, 99, carHandle)){ //cut up the car file line by line and put the bits into the car array.
item = strtok(line,";");
strcpy(car[carcount].reservationID,item);
item = strtok(NULL,";");
strcpy(car[carcount].carID,item);
item = strtok(NULL,";");
strcpy(car[carcount].carYOM,item);
item = strtok(NULL,";");
strcpy(car[carcount].carMake,item);
item = strtok(NULL,";");
strcpy(car[carcount].carModel,item);
item = strtok(NULL,";");
strcpy(car[carcount].carFuel,item);
item = strtok(NULL,"\n");
strcpy(car[carcount].catagory,item);
carcount++;
}
fclose(carHandle);
printf("Enter todays date:");
scanf("%s", choice);
for (k=0;k<=rescount; k++){
if (strcmp(choice,reservation[k].reservationEndDate)<0 && strcmp(choice,reservation[k].reservationStartDate)>0){
for (i=0;i<=carcount; i++){
if (strcmp(car[k].reservationID,reservation[i].reservationID)==0){
printf("\nreservationID: %s\nreservationStartTime: %s\ncustomerID: %s\ncarid: %s\nyom: %s\nmake: %s\nmodel: %s\nfueltype: %s\ncategory: %s\n\n", car[k].reservationID, reservation[i].reservationStartTime, reservation[i].customerID, car[k].carID, car[k].carYOM, car[k].carMake, car[k].carModel, car[k].carFuel, car[k].catagory);
//printf("This works");
goto outofloop;
}else printf("\n\nno matching resID in cars.txt\n");
}
}
else printf("\nall the cars are available\n");
break;
}
outofloop:
return(0);
}
输入今天日期:2012年2月13日 所有的车都有
按任意键继续…您没有正确计算车辆和预订的数量: 在这两个循环中(一个读取cars,另一个读取reservation),您使用
reccount
作为计数器。
您需要使用两个计数器,carcount
和rescount
。
随后,您需要在for循环中使用carcount和rescount
for (k=0;k<=rescount; k++){
if (strcmp(choice,reservation[k].reservationEndDate)<0 && strcmp(choice,reservation[k].reservationStartDate)>0){
for (i=0;i<=carcount; i++){
if(fscanf(filehandle, "R%03u...\n", &car[carcount].reservationID, ...) == EOF)
break;
这将使您的文件扫描更加健壮,并将其变成一行printf(“\n\n没有匹配的resID in cars.txt\n”)
一般来说,您是否尝试过调试代码?gdb是一个非常强大的工具。您可以使用它来跟踪程序流程,随时暂停程序查看可变内容。我已经解决了这个问题。问题是使用resID作为公共标识符而不是carID
谢谢大家的帮助。您对两个阵列只使用一个计数器,即
car
和reservation
。您确定c是正确的选择吗?你的任务听起来像是一个完美的例子,说明了SQL的用途。为了我的目的,代码必须是c语言。
reservationID: R002
reservationStartTime: 10:00A.M
customerID: C002
carid: V001
yom: 2003
make: Toyota
model: Camry
fueltype: Petrol
category: Budget
Press any key to continue . . .
for (k=0;k<=rescount; k++){
if (strcmp(choice,reservation[k].reservationEndDate)<0 && strcmp(choice,reservation[k].reservationStartDate)>0){
for (i=0;i<=carcount; i++){
for(carcount = 0; carcount < CAR_MAX; carcount++)
if(fscanf(filehandle, "R%03u...\n", &car[carcount].reservationID, ...) == EOF)
break;