Student Information Management System --C language version

A subject of analysis:
1. Features Overview:
1) Student Information Query
2) add student information
3) modify student information
4) delete student information
5) Refresh Student Information
6) to save student information
7) output current student information
2. questions asked :
1) establishing a structure student information system
2) to achieve the basic functions of the seven
3) using student information file stores
two algorithms configured.
1. difficulties parsing operation on a file ----
1.1 document reader

FILE * fp;
	if ((fp = fopen(filename, "r")) == NULL) return 0;
	//从文件读取信息 
	while (fscanf(fp, "%s %s %s %d %d %d %d ", &stu[j].StudentId, &stu[j].StudentName, &stu[j].StudentAge, &stu[j].StudentSex, &stu[j].score[0], &stu[j].score[1], &stu[j].score[2]) == 7) {
		j++;
	}

1.2 File Write

FILE * fp；
fp = fopen(filename, "w");
	for (i = 0; i < n; i++){
		fprintf(fp, "%s%s%d%c%.lf%.lf%.lf\n", stu[i].StudentId, stu[i].StudentName, stu[i].StudentAge, stu[i].StudentSex,
			stu[i].score[0], stu[i].score[1], stu[i].score[2]);
	}

2. flowchart

3. Seven function implements the basic functions ----
3.1 menu functions: to establish communication between the user and the program menu

void menu()/* 界面*/
{
	int num;
	printf(" \n\n                    \n\n");
	printf("  ******************************************************\n\n");
	printf("  *                学生信息管理系统                    *\n \n");
	printf("  ******************************************************\n\n");
	printf("*********************系统功能菜单*************************       \n");
	printf("     ----------------------   ----------------------   \n");
	printf("     *********************************************     \n");
	printf("     * 0.系统帮助及说明  * *  1.刷新学生信息   *     \n");
	printf("     *********************************************     \n");
	printf("     * 2.查询学生信息    * *  3.修改学生信息   *     \n");
	printf("     *********************************************     \n");
	printf("     * 4.增加学生信息    * *  5.按学号删除信息 *     \n");
	printf("     *********************************************     \n");
	printf("     * 6.显示当前信息    * *  7.保存当前学生信息*     \n");
	printf("     ********************** **********************     \n");
	printf("     * 8.退出系统        *                            \n");
	printf("     **********************                            \n");
	printf("     ----------------------   ----------------------                           \n");
	printf("请选择菜单编号:");
	scanf("%d", &num);
	switch (num)
	{
	case 0:help(); break;
	case 1:flush(); break;
	case 2:seek(); break;
	case 3:modify(); break;
	case 4:insert(); break;
	case 5:del(); break;
	case 6:display(); break;
	case 7:save(); break;
	case 8:
		k = 0; 
		printf("即将退出程序!\n");
		break;
	default:printf("请在0-8之间选择\n");
	}
}

3.2 system and help explain the function: For the initial contact Student Information Management System User Reference

void help()
{
	printf("\n0.欢迎使用系统帮助！\n");
	printf("\n1.初次进入系统后,请先选择增加学生信息;\n");
	printf("\n2.按照菜单提示键入数字代号;\n");
	printf("\n3.增加学生信息后,切记保存;\n");
	printf("\n4.谢谢您的使用！\n");
}

3.3 Student Information refresh function
Function: After calling refresh the information function, the file is no longer student information

int flush(){
	char filename[LEN + 1];
	int i = 0;
	printf("请输入要刷新学生信息的文件名：\n");
	scanf("%s", filename);
	int j = 0;
	FILE * fp;
	if ((fp = fopen(filename, "r")) == NULL) return 0;
	//从文件读取信息 
	while (fscanf(fp, "%s %s %s %d %d %d %d ", &stu[j].StudentId, &stu[j].StudentName, &stu[j].StudentAge, &stu[j].StudentSex, &stu[j].score[0], &stu[j].score[1], &stu[j].score[2]) == 7) {
		j++;
	}
	n = j;
	printf("刷新成功!!!");
	return n;
}

3.4 Query student information Function
Function: enters a query the student number or name, compared with the student information system, if they are same, the basic information of the student is output; otherwise, the output of the students are not in the management system exist
query:
1) in accordance with the Student ID inquiry
2) query by name

void seek() /*查找*/
{
	int i, item, flag;
	char s1[21]; /* 以姓名和学号最长长度+1为准*/
	printf("------------------\n");
	printf("-----1.按学号查询-----\n");
	printf("-----2.按姓名查询-----\n");
	printf("-----3.退出本菜单-----\n");
	printf("------------------\n");
	while (1)
	{
		printf("请选择子菜单编号:");
		scanf("%d", &item);
		flag = 0;
		switch (item)
		{
		case 1:
			printf("请输入要查询的学生的学号:\n");
			scanf("%s", s1);
			for (i = 0; i<n; i++)
			if (strcmp(s1,stu[i].StudentId) == 0)
			{
				flag = 1;
				printf("学生学号\t学生姓名\t年龄\t性别\tC语言成绩\t高等数学\t大学英语成绩\n");
				printf("--------------------------------------------------------------------\n");
				printf("%s\t%s\t%d\t%6\t%.1f\t%.1f\t%.1f\n", stu[i].StudentId,stu[i].StudentName,stu[i].StudentAge,stu[i].StudentSex,stu[i].score[0],stu[i].score[1],stu[i].score[2]);
			}
			if (0 == flag)
				printf("该学号不存在！\n"); break;
		case 2:
			printf("请输入要查询的学生的姓名:\n");
			scanf("%s", s1);
			for (i = 0; i<n; i++)
			if (strcmp(stu[i].StudentName, s1) == 0)
			{
				flag = 1;
				printf("学生学号\t学生姓名\t年龄\t性别\tC语言成绩\t高等数学\t大学英语成绩\n");
				printf("--------------------------------------------------------------------\n");
				printf("%s\t%s\t%d\t%c\t%.1f\t%.1f\t%.1f\n", stu[i].StudentId, stu[i].StudentName, stu[i].StudentAge, stu[i].StudentSex, stu[i].score[0], stu[i].score[1], stu[i].score[2]);
			}
			if (0 == flag)
				printf("该姓名不存在！\n"); break;
		case 3:return;
		default:printf("请在1-3之间选择\n");
		}
	}
}

3.5 Review Student information
Function: Select to modify the number of school students learning content through the input number, thereby completing the operation of the modification information;

//修改学生信息
void modify() /*修改信息*/
{
	int i, item, num = -1;
	char sex1, s1[LEN + 1], s2[LEN + 1]; /* 以姓名和学号最长长度+1为准*/
	float score1;
	printf("请输入要要修改的学生的学号:\n");
	scanf("%s", s1);
	for (i = 0; i < n; i++){
		if (strcmp(stu[i].StudentId, s1) == 0){/*比较字符串是否相等*/
			num = i;
			printf("------------------\n");
			printf("1.修改姓名\n");
			printf("2.修改年龄\n");
			printf("3.修改性别\n");
			printf("4.修改C语言成绩\n");
			printf("5.修改高等数学成绩\n");
			printf("6.修改大学英语成绩\n");
			printf("7.退出本菜单\n");
			printf("------------------\n");
			while (1)
			{
				printf("请选择子菜单编号:");
				scanf("%d", &item);
				switch (item)
				{
				case 1:
					printf("请输入新的姓名:\n");
					scanf("%s", s2);
					strcpy(stu[num].StudentName, s2);
					break;
				case 2:
					printf("请输入新的年龄:\n");
					scanf("%d", stu[num].StudentAge);
					break;
				case 3:
					printf("请输入新的性别:\n");
					scanf("%s", &sex1);
					stu[i].StudentSex = sex1;
					break;
				case 4:
					printf("请输入新的C语言成绩:\n");
					scanf("%f", &score1);
					stu[num].score[0] = score1;
					break;
				case 5:
					printf("请输入新的高等数学成绩:\n");
					scanf("%f", &score1);
					stu[num].score[1] = score1;
					break;
				case 6:
					printf("请输入新的大学英语成绩:\n");
					scanf("%f", &score1);
					stu[num].score[2] = score1;
					break;
				case 7:	return;
				default:printf("请在1-7之间选择\n");
				}
			}
			printf("修改完毕！请及时保存！\n");
		}
		else{
			printf("没有该学生学号!!!");
		}
	}
}

3.6 student information to add function
function: add student information, and saved to a file

//添加学生信息函数
void insert() /*插入函数*/
{
	int i = n, j, flag;
	printf("请输入待增加的学生数:\n");
	scanf("%d", &m);
	if (m > 0){
		do
		{
			flag = 1;
			while (flag)
			{
				flag = 0;
				printf("请输入第%d位学生的学号:\n", i + 1);
				scanf("%s", stu[i].StudentId);
				for (j = 0; j < i; j++){
					if (strcmp(stu[i].StudentId, stu[j].StudentId) == 0){
						printf("该学号已存在，请重新输入！\n");
						flag = 1;
						break;
					}
				}
			}
			printf("请输入第%d 个学生的姓名:\n", i+1);
			scanf("%s", stu[i].StudentName);
			printf("请输入第%d 个学生的年龄:\n", i+1);
			scanf("%d", &stu[i].StudentAge);
			printf("请输入第%d 个学生的性别:\n", i+1);
			scanf(" %c", &stu[i].StudentSex);
			printf("请输入第%d 个学生的C语言成绩\n",i+1);
			scanf("%f", &stu[i].score[0]);
			printf("请输入第%d 个学生的高等数学成绩:\n", i+1);
			scanf("%f", &stu[i].score[1]);
			printf("请输入第%d 个学生的大学英语成绩:\n", i+1);
			scanf("%f", &stu[i].score[2]);
			if (0 == flag){
				i++;
			}
		} while (i<n + m);
	}
		n += m;
		printf("学生信息增加完毕！！！\n");
		system("pause");
}

3.7 delete student information functions
function: by entering the number you want to delete school student information, delete all the information in the student management system;

//删除学生信息函数
void del()
{
	int i, j, flag = 0;
	char s1[LEN + 1];
	printf("请输入要删除学生的学号:\n");
	scanf("%s", s1);
	for (i = 0; i < n; i++){
		if (strcpy(stu[i].StudentId, s1) == 0){
			flag = 1;
			//要删除学生后面的学生往前移一位
			for (j = i; j < n - 1; j++){
				stu[j] = stu[j + 1];
			}
		}
	}
		//查找失败
		if (0 == flag){
			printf("该学号不存在!!!\n");
		}
		if (1 == flag){
			printf("删除成功！！！");
			//删除成功，学生人数减1
			n--;
		}
		system("pause");
}

3.8 displays the current student information
functions: All student information student information management system can be output after various operations;

//显示全部数据信息
void display()
{
	int i;
	printf("共有%d位学生的信息:\n", n);
	if (0 != n)
	{
		printf("学生学号 \t学生姓名 \t年龄   \t性别   \tC语言成绩\t高等数学 \t大学英语成绩\n");
		printf("--------------------------------------------------------------------\n");
		for (i = 0; i<n; i++)
		{
			printf("%s \t%s \t%d   \t%c   \t%.1f\t%.1f \t%.1f\n", stu[i].StudentId, stu[i].StudentName, stu[i].StudentAge, stu[i].StudentSex, stu[i].score[0],stu[i].score[1],stu[i].score[2]);
		}
	}
	system("pause");
}

3.8 save student information
to save student information will be certain operations to the specified file: function

void save(){
	int i;
	FILE *fp;
	char filename[LEN + 1];
	printf("请输入要保存的文件名：\n");
	scanf("%s", filename);
	fp = fopen(filename, "w");
	for (i = 0; i < n; i++){
		fprintf(fp, "%s%s%d%c%.lf%.lf%.lf\n", stu[i].StudentId, stu[i].StudentName, stu[i].StudentAge, stu[i].StudentSex,
			stu[i].score[0], stu[i].score[1], stu[i].score[2]);
	}
	printf("保存成功！！！\n");
	fclose(fp);
	system("pause");
}

III. Source code

#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>	/*I/O函数*/
#include<stdlib.h>	/*其它说明*/
#include<string.h>	/*字符串函数*/

#define LEN 15		/* 学号和姓名最大字符数,实际请更改*/
#define N 50		/* 最大学生人数,实际请更改*/

int k = 1, n = 0, m = 0;/* n代表当前记录的学生人数*/

//函数声明
void readfile();
void seek();
void modify();
void insert();
void del();
void display();
void save();
void menu();

//结构体保存学生信息
struct student{
	char StudentId[LEN+1];
	char StudentName[LEN+1];
	int StudentAge;
	char StudentSex;
	float score[3];
}stu[N];

//主函数
int main()
{
	while (k)
	{
		menu();
	}
	system("pause");
	return 0;
}

//系统帮助函数
void help()
{
	printf("\n0.欢迎使用系统帮助！\n");
	printf("\n1.初次进入系统后,请先选择增加学生信息;\n");
	printf("\n2.按照菜单提示键入数字代号;\n");
	printf("\n3.增加学生信息后,切记保存;\n");
	printf("\n4.谢谢您的使用！\n");
}

//刷新文件
int flush(){
	char filename[LEN + 1];
	int i = 0;
	printf("请输入要刷新学生信息的文件名：\n");
	scanf("%s", filename);
	int j = 0;
	FILE * fp;
	if ((fp = fopen(filename, "r")) == NULL) return 0;
	//从文件读取信息 
	while (fscanf(fp, "%s %s %s %d %d %d %d ", &stu[j].StudentId, &stu[j].StudentName, &stu[j].StudentAge, &stu[j].StudentSex, &stu[j].score[0], &stu[j].score[1], &stu[j].score[2]) == 7) {
		j++;
	}
	n = j;
	printf("刷新成功!!!");
	return n;
}

//查找学生信息
void seek() /*查找*/
{
	int i, item, flag;
	char s1[21]; /* 以姓名和学号最长长度+1为准*/
	printf("------------------\n");
	printf("-----1.按学号查询-----\n");
	printf("-----2.按姓名查询-----\n");
	printf("-----3.退出本菜单-----\n");
	printf("------------------\n");
	while (1)
	{
		printf("请选择子菜单编号:");
		scanf("%d", &item);
		flag = 0;
		switch (item)
		{
		case 1:
			printf("请输入要查询的学生的学号:\n");
			scanf("%s", s1);
			for (i = 0; i<n; i++)
			if (strcmp(s1,stu[i].StudentId) == 0)
			{
				flag = 1;
				printf("学生学号\t学生姓名\t年龄\t性别\tC语言成绩\t高等数学\t大学英语成绩\n");
				printf("--------------------------------------------------------------------\n");
				printf("%s\t%s\t%d\t%6\t%.1f\t%.1f\t%.1f\n", stu[i].StudentId,stu[i].StudentName,stu[i].StudentAge,stu[i].StudentSex,stu[i].score[0],stu[i].score[1],stu[i].score[2]);
			}
			if (0 == flag)
				printf("该学号不存在！\n"); break;
		case 2:
			printf("请输入要查询的学生的姓名:\n");
			scanf("%s", s1);
			for (i = 0; i<n; i++)
			if (strcmp(stu[i].StudentName, s1) == 0)
			{
				flag = 1;
				printf("学生学号\t学生姓名\t年龄\t性别\tC语言成绩\t高等数学\t大学英语成绩\n");
				printf("--------------------------------------------------------------------\n");
				printf("%s\t%s\t%d\t%c\t%.1f\t%.1f\t%.1f\n", stu[i].StudentId, stu[i].StudentName, stu[i].StudentAge, stu[i].StudentSex, stu[i].score[0], stu[i].score[1], stu[i].score[2]);
			}
			if (0 == flag)
				printf("该姓名不存在！\n"); break;
		case 3:return;
		default:printf("请在1-3之间选择\n");
		}
	}
}

//修改学生信息
void modify() /*修改信息*/
{
	int i, item, num = -1;
	char sex1, s1[LEN + 1], s2[LEN + 1]; /* 以姓名和学号最长长度+1为准*/
	float score1;
	printf("请输入要要修改的学生的学号:\n");
	scanf("%s", s1);
	for (i = 0; i < n; i++){
		if (strcmp(stu[i].StudentId, s1) == 0){/*比较字符串是否相等*/
			num = i;
			printf("------------------\n");
			printf("1.修改姓名\n");
			printf("2.修改年龄\n");
			printf("3.修改性别\n");
			printf("4.修改C语言成绩\n");
			printf("5.修改高等数学成绩\n");
			printf("6.修改大学英语成绩\n");
			printf("7.退出本菜单\n");
			printf("------------------\n");
			while (1)
			{
				printf("请选择子菜单编号:");
				scanf("%d", &item);
				switch (item)
				{
				case 1:
					printf("请输入新的姓名:\n");
					scanf("%s", s2);
					strcpy(stu[num].StudentName, s2);
					break;
				case 2:
					printf("请输入新的年龄:\n");
					scanf("%d", stu[num].StudentAge);
					break;
				case 3:
					printf("请输入新的性别:\n");
					scanf("%s", &sex1);
					stu[i].StudentSex = sex1;
					break;
				case 4:
					printf("请输入新的C语言成绩:\n");
					scanf("%f", &score1);
					stu[num].score[0] = score1;
					break;
				case 5:
					printf("请输入新的高等数学成绩:\n");
					scanf("%f", &score1);
					stu[num].score[1] = score1;
					break;
				case 6:
					printf("请输入新的大学英语成绩:\n");
					scanf("%f", &score1);
					stu[num].score[2] = score1;
					break;
				case 7:	return;
				default:printf("请在1-7之间选择\n");
				}
			}
			printf("修改完毕！请及时保存！\n");
		}
		else{
			printf("没有该学生学号!!!");
		}
	}
}

void sort()//按学号排序
{
	int i, j, k, *p, *q, s;
	char temp[LEN + 1], ctemp;
	float ftemp;
	for (i = 0; i<n - 1; i++)
	{
		for (j = n - 1; j>i; j--)
		if (strcmp(stu[j - 1].StudentId, stu[j].StudentId)>0)
		{
			strcpy(temp, stu[j - 1].StudentId);
			strcpy(stu[j - 1].StudentId, stu[j].StudentId);
			strcpy(stu[j].StudentId, temp);
			strcpy(temp, stu[j - 1].StudentName);
			strcpy(stu[j - 1].StudentName, stu[j].StudentName);
			strcpy(stu[j].StudentName, temp);
			ctemp = stu[j - 1].StudentSex;
			stu[j - 1].StudentSex = stu[j].StudentSex;
			stu[j].StudentSex = ctemp;
			p = &stu[j - 1].StudentAge;
			q = &stu[j].StudentAge;
			s = *q;
			*q = *p;
			*p = s;
			for (k = 0; k<3; k++)
			{
				ftemp = stu[j - 1].score[k];
				stu[j - 1].score[k] = stu[j].score[k];
				stu[j].score[k] = ftemp;
			}
		}
	}
}

//添加学生信息函数
void insert() /*插入函数*/
{
	int i = n, j, flag;
	printf("请输入待增加的学生数:\n");
	scanf("%d", &m);
	if (m > 0){
		do
		{
			flag = 1;
			while (flag)
			{
				flag = 0;
				printf("请输入第%d位学生的学号:\n", i + 1);
				scanf("%s", stu[i].StudentId);
				for (j = 0; j < i; j++){
					if (strcmp(stu[i].StudentId, stu[j].StudentId) == 0){
						printf("该学号已存在，请重新输入！\n");
						flag = 1;
						break;
					}
				}
			}
			printf("请输入第%d 个学生的姓名:\n", i+1);
			scanf("%s", stu[i].StudentName);
			printf("请输入第%d 个学生的年龄:\n", i+1);
			scanf("%d", &stu[i].StudentAge);
			printf("请输入第%d 个学生的性别:\n", i+1);
			scanf(" %c", &stu[i].StudentSex);
			printf("请输入第%d 个学生的C语言成绩\n",i+1);
			scanf("%f", &stu[i].score[0]);
			printf("请输入第%d 个学生的高等数学成绩:\n", i+1);
			scanf("%f", &stu[i].score[1]);
			printf("请输入第%d 个学生的大学英语成绩:\n", i+1);
			scanf("%f", &stu[i].score[2]);
			if (0 == flag){
				i++;
			}
		} while (i<n + m);
	}
		n += m;
		printf("学生信息增加完毕！！！\n");
		system("pause");
}

//删除学生信息函数
void del()
{
	int i, j, flag = 0;
	char s1[LEN + 1];
	printf("请输入要删除学生的学号:\n");
	scanf("%s", s1);
	for (i = 0; i < n; i++){
		if (strcpy(stu[i].StudentId, s1) == 0){
			flag = 1;
			//要删除学生后面的学生往前移一位
			for (j = i; j < n - 1; j++){
				stu[j] = stu[j + 1];
			}
		}
	}
		//查找失败
		if (0 == flag){
			printf("该学号不存在!!!\n");
		}
		if (1 == flag){
			printf("删除成功！！！");
			//删除成功，学生人数减1
			n--;
		}
		system("pause");
}

//显示全部数据信息
void display()
{
	int i;
	printf("共有%d位学生的信息:\n", n);
	if (0 != n)
	{
		printf("学生学号 \t学生姓名 \t年龄   \t性别   \tC语言成绩\t高等数学 \t大学英语成绩\n");
		printf("--------------------------------------------------------------------\n");
		for (i = 0; i<n; i++)
		{
			printf("%s \t%s \t%d   \t%c   \t%.1f\t%.1f \t%.1f\n", stu[i].StudentId, stu[i].StudentName, stu[i].StudentAge, stu[i].StudentSex, stu[i].score[0],stu[i].score[1],stu[i].score[2]);
		}
	}
	system("pause");
}

void save(){
	int i;
	FILE *fp;
	char filename[LEN + 1];
	printf("请输入要保存的文件名：\n");
	scanf("%s", filename);
	fp = fopen(filename, "w");
	for (i = 0; i < n; i++){
		fprintf(fp, "%s%s%d%c%.lf%.lf%.lf\n", stu[i].StudentId, stu[i].StudentName, stu[i].StudentAge, stu[i].StudentSex,
			stu[i].score[0], stu[i].score[1], stu[i].score[2]);
	}
	printf("保存成功！！！\n");
	fclose(fp);
	system("pause");
}

void menu()/* 界面*/
{
	int num;
	printf(" \n\n                    \n\n");
	printf("  ******************************************************\n\n");
	printf("  *                学生信息管理系统                    *\n \n");
	printf("  ******************************************************\n\n");
	printf("*********************系统功能菜单*************************       \n");
	printf("     ----------------------   ----------------------   \n");
	printf("     *********************************************     \n");
	printf("     * 0.系统帮助及说明  * *  1.刷新学生信息   *     \n");
	printf("     *********************************************     \n");
	printf("     * 2.查询学生信息    * *  3.修改学生信息   *     \n");
	printf("     *********************************************     \n");
	printf("     * 4.增加学生信息    * *  5.按学号删除信息 *     \n");
	printf("     *********************************************     \n");
	printf("     * 6.显示当前信息    * *  7.保存当前学生信息*     \n");
	printf("     ********************** **********************     \n");
	printf("     * 8.退出系统        *                            \n");
	printf("     **********************                            \n");
	printf("     ----------------------   ----------------------                           \n");
	printf("请选择菜单编号:");
	scanf("%d", &num);
	switch (num)
	{
	case 0:help(); break;
	case 1:flush(); break;
	case 2:seek(); break;
	case 3:modify(); break;
	case 4:insert(); break;
	case 5:del(); break;
	case 6:display(); break;
	case 7:save(); break;
	case 8:
		k = 0; 
		printf("即将退出程序!\n");
		break;
	default:printf("请在0-8之间选择\n");
	}
}

Four debug, and test results
1. Debug:

2. Test:
does not meet with the input data type is defined, the program is running error occurs

3. Results:
(1) to (9) is a continuous run experiments The results
(1) run menu

(2) add student information

(3) to save student information

(4) show all information

(5) modify student information

(6) All modified information

(7) Refresh Student Information

(8) to save student information

All the information (9) display refresh

V. Summary:
write a full-featured, user-friendly operation of the student management system, need long-term practice and accumulation.
A good way to test during practice, learned after practice, it can be better absorbed by itself. When writing an application program operating documents for me, it is a question without much practice, so I'm writing this part of the program, or some difficulty. The program is also a problem that, when the input data is inconsistent with the definition of a program error may occur during operation, modification approach still thinking, and I welcome everyone to encourage each other.