求用c语言完成以下数据库的问题

Question

有没有比较厉害的人能给我写出满足以下要求的代码，想要带着简要解释的，并能给出符合数据文件和结果示意图，想要一个完整的函数

Answer 1

以下是一个使用C语言实现的学生-课程数据库应用程序，包括添加、查找、删除和修改功能。程序使用文件来保存学生信息，并在控制台上显示结果。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_STUDENTS 100
#define FILE_NAME "students.dat"

typedef struct {
    char id[10];
    char name[20];
    char gender[5];
    int age;
    char department[20];
} Student;

// Function prototypes
void add(Student students[], int *count);
void searchById(Student students[], int count, const char *id);
void modify(Student students[], int count);
void deleteById(Student students[], int *count, const char *id);
void saveToFile(Student students[], int count);
void display(Student students[], int count);
void displayFile();

int main() {
    Student students[MAX_STUDENTS];
    int count = 0;
    char choice;

    FILE *file = fopen(FILE_NAME, "rb");
    if (file != NULL) {
        fread(students, sizeof(Student), MAX_STUDENTS, file);
        fclose(file);
        count = MAX_STUDENTS;
    }

    do {
        printf("
1. Add student
");
        printf("2. Search by ID
");
        printf("3. Modify
");
        printf("4. Delete by ID
");
        printf("5. Display all
");
        printf("6. Display file content
");
        printf("7. Exit
");
        printf("Enter your choice: ");
        scanf(" %c", &choice);

        switch(choice) {
            case '1':
                add(students, &count);
                break;
            case '2': {
                char id[10];
                printf("Enter ID to search: ");
                scanf("%s", id);
                searchById(students, count, id);
                break;
            }
            case '3':
                modify(students, count);
                break;
            case '4': {
                char id[10];
                printf("Enter ID to delete: ");
                scanf("%s", id);
                deleteById(students, &count, id);
                break;
            }
            case '5':
                display(students, count);
                break;
            case '6':
                displayFile();
                break;
            case '7':
                saveToFile(students, count);
                printf("Exiting program.
");
                break;
            default:
                printf("Invalid choice. Please try again.
");
        }
    } while (choice != '7');

    return 0;
}

void add(Student students[], int *count) {
    if (*count >= MAX_STUDENTS) {
        printf("Database full. Cannot add more students.
");
        return;
    }

    printf("Enter student details:
");
    printf("ID: ");
    scanf("%s", students[*count].id);
    printf("Name: ");
    scanf("%s", students[*count].name);
    printf("Gender: ");
    scanf("%s", students[*count].gender);
    printf("Age: ");
    scanf("%d", &students[*count].age);
    printf("Department: ");
    scanf("%s", students[*count].department);

    (*count)++;
}

void searchById(Student students[], int count, const char *id) {
    int found = 0;
    for (int i = 0; i < count; i++) {
        if (strcmp(students[i].id, id) == 0) {
            printf("Student found:
");
            printf("ID: %s
", students[i].id);
            printf("Name: %s
", students[i].name);
            printf("Gender: %s
", students[i].gender);
            printf("Age: %d
", students[i].age);
            printf("Department: %s
", students[i].department);
            found = 1;
            break;
        }
    }
    if (!found) {
        printf("Student with ID %s not found.
", id);
    }
}

void modify(Student students[], int count) {
    for (int i = 0; i < count; i++) {
        students[i].age++;
    }
    printf("All students ages have been incremented by 1.
");
}

void deleteById(Student students[], int *count, const char *id) {
    int found = 0;
    for (int i = 0; i < *count; i++) {
        if (strcmp(students[i].id, id) == 0) {
            for (int j = i; j < *count - 1; j++) {
                students[j] = students[j + 1];
            }
            (*count)--;
            printf("Student with ID %s deleted.
", id);
            found = 1;
            break;
        }
    }
    if (!found) {
        printf("Student with ID %s not found.
", id);
    }
}

void saveToFile(Student students[], int count) {
    FILE *file = fopen(FILE_NAME, "wb");
    if (file != NULL) {
        fwrite(students, sizeof(Student), count, file);
        fclose(file);
    } else {
        printf("Error saving to file.
");
    }
}

void display(Student students[], int count) {
    printf("Student details:
");
    for (int i = 0; i < count; i++) {
        printf("ID: %s, Name: %s, Gender: %s, Age: %d, Department: %s
",
               students[i].id, students[i].name, students[i].gender,
               students[i].age, students[i].department);
    }
}

void displayFile() {
    FILE *file = fopen(FILE_NAME, "rb");
    if (file != NULL) {
        Student student;
        printf("Student details from file:
");
        while (fread(&student, sizeof(Student), 1, file)) {
            printf("ID: %s, Name: %s, Gender: %s, Age: %d, Department: %s
",
                   student.id, student.name, student.gender,
                   student.age, student.department);
        }
        fclose(file);
    } else {
        printf("Error displaying file content.
");
    }
}

这个程序可以添加、查找、修改和删除学生记录，并在控制台上显示结果。学生信息保存在名为 "students.dat" 的二进制文件中。

以下是程序的工作示意图：

1. Add student
2. Search by ID
3. Modify
4. Delete by ID
5. Display all
6. Display file content
7. Exit
Enter your choice: 1
Enter student details:
ID: 950011
Name: 李勇日
Gender: 男
Age: 20
Department: CS

1. Add student
2. Search by ID
3. Modify
4. Delete by ID
5. Display all
6. Display file content
7. Exit
Enter your choice: 5
Student details:
ID: 950011, Name: 李勇日, Gender: 男, Age