通过这几天学习Mysql数据库，对其也有了基本的了解，为了加深印象，于是就写了一个最简易的学生信息管理系统。
一：基本要求
1.通过已知用户名和密码进行登录；
2.可以显示菜单；
3.可以随时插入学生信息；
4.可以删除学生信息；
5.可以通过学生姓名或学号显示学生所有信息；
还可以修改学生信息，添加学生表格属性等等，，，这些实现都基本类似上述的（这些不想写了，最简易的学生信息管理系统）；
二：步骤
1.写一个sql脚本，包括创建数据库，使用数据库，创建学生信息表格，插入大部分学生信息。
student_information.sql
create database school_db character set gbk; use school_db; create table students (
student_id int unsigned not null primary key,
name char() not null,
sex char() not null,
birth date not null,
politily char() not null
); insert into students values (,"张三","男","1994-12-2","自动化1");
insert into students values (,"李四","男","1989-10-8","自动化2");
insert into students values (,"王五","男","1994-8-8","自动化2");
insert into students values (,"路人1","女","1994-7-9","自动化2");
insert into students values (,"路人2","男","1994-12-8","自动化2");
insert into students values (,"路人3","女","1994-11-8","自动化2");
insert into students values (,"路人4","男","1992-1-23","自动化2"); 。。。。
执行脚本：
第一种方法： mysql -h localhost -u root -p 密码 < student_information.sql;
第二种方法：已经登录了mysql， source student_information.sql；
2.编写代码
#include <stdlib.h>
#include <stdio.h>
#include <mysql.h>
#include <ctype.h>
#include <curses.h> //#define MAX_PASSWD_LEN 16 void printf_mune(void);
char *getPasswd(void);
int insert_student(void);
int delete_student(void);
int inquiry_student(void); int main(int argc,char** argv)
{
char user[];
char passwd[];
char c;
int i;
printf("***********************************************************\n");
printf("* welcome to student information managent system *\n");
printf("***********************************************************\n");
// printf(" user: ______________\b\b\b\b\b\b\b\b\n");
// printf(" psaawd:______\b\b\b\b\b\b\n"); while(){ printf(" user:");
scanf("%s", user); printf(" passwd:"); scanf("%s",passwd); /* while ((c=getch())!='\n')
{
if (i<MAX_PASSWD_LEN && isprint(c)) //isprint函数判断c是否是可打印字符
{
passwd[i++] = c;
putchar('*');
}
else if (i>0 && c=='\b')
{
--i;
putchar('\b');
putchar(' ');
putchar('\b');
}
}
putchar('\n');
passwd[i] = '\0'; */ if(!strncmp(user, "qigaohua", )){
if(!strncmp(passwd, "", ))
break;
else {
printf("passwd error\n");
continue;
}
}else{
printf("user error\n");
continue;
}
} printf("login sucess\n");
while(){
printf_mune();
getchar(); //问题1 必须加
c = fgetc(stdin);
switch(c){
case 'I':
insert_student();
break;
case 'D':
delete_student();
break;
case 'S':
inquiry_student();
break;
case 'Q':
return ;
break;
default:
;
}
}
printf("exit sucess\n");
return ; } /*getc()和getchar()函数想必大家都经常用到，但它们都在输入的同时显示输入内容，并由回车终止输入。
为了不显示输入内容，我们调用另外一个函数getch()，它包含在头文件中。该函数可以在输入的同时不显示
输入内容，并在输入完成后不需回车而自动终止输入。与此同时，该头文件中还包含另外一个函数getche()，
它和getch()功能相同，唯一的区别是输入的同时显示输入的内容。本文我们只用到getch();*/
/*char *getPasswd()
{
unsigned char c;
passwd =(char*)malloc(8);
int i = 0; while ((c=getch())!='\r')
{
if (i<MAX_PASSWD_LEN && isprint(c)) //isprint函数判断c是否是可打印字符
{
passwd[i++] = c;
putchar('*');
}
else if (i>0 && c=='\b')
{
--i;
putchar('\b');
putchar(' ');
putchar('\b');
}
}
putchar('\n');
passwd[i] = '\0'; return passwd;
}*/ void printf_mune(void)
{
printf("The following operations can be performed\n");
printf("1. insert student information input I\n");
printf("2. delete student information input D\n");
printf("3. inquiry student information input S\n");
printf("4. exit student information managent system input Q\n");
} int insert_student(void)
{
MYSQL mysql;
char sql[];
char k;
char id[], name[], sex[],birth[],potility[]; mysql_init(&mysql);
if(!mysql_real_connect(&mysql, "localhost", "root",NULL,"school_db",,NULL,)){
printf("ERROR: %d--%s\n", mysql_errno(&mysql), mysql_error(&mysql));
exit(-);
}
mysql_set_character_set(&mysql, "utf8");
while() { printf("please input student information\n");
printf("student_id: ");
fflush(stdin);
scanf("%s",id);
// fgets(id, 10, stdin);
printf("\nname: ");
scanf("%s",name);
// fgets(name, 20, stdin); printf("\nsex: ");
scanf("%s",sex); printf("\nbirth: ");
scanf("%s",birth);
// fgets(birth, 15, stdin); printf("\npolitily: ");
scanf("%s",potility);
// fgets(potility, 20, stdin); printf("\nplease input y or n or q\n");
// read(stdin, k, 1);
getchar(); //注意要加
k = fgetc(stdin);
if(k == 'n')
continue;
else if(k == 'q')
break;
else if(k == 'y'){
sprintf(sql, "insert into students values (\"%s\", \"%s\", \"%s\", \"%s\", \"%s\");", id, name,sex, birth, potility);
printf("\n%s",sql); if(mysql_query(&mysql, sql)){
printf("\ninsert failed: %d--%s\n", mysql_errno(&mysql), mysql_error(&mysql));
continue;
}
printf("\ninsert sucess\n"); printf("you want exit? input q\n");
getchar();
k = fgetc(stdin);
if(k == 'q')
break;
}
}
mysql_close(&mysql);
return ;
} int delete_student(void)
{
MYSQL mysql;
char sql[];
char id[], name[];
char k; mysql_init(&mysql);
if(!mysql_real_connect(&mysql, "localhost", "root",NULL,"school_db",,NULL,)){
printf("ERROR: %d--%s\n", mysql_errno(&mysql), mysql_error(&mysql));
exit(-);
}
mysql_set_character_set(&mysql, "utf8"); while(){
printf("please input you want delete student id or name, selset i or n or q\n");
getchar(); //注意
k = fgetc(stdin);
if(k == 'i') {
printf("student id: ");
scanf("%s",id);
//fgets(id, 10, stdin);
sprintf(sql, "delete from students where student_id=\"%s\";", id);
}else if(k == 'n'){
printf("\nstudent name: ");
scanf("%s",name);
//fgets(name, 20, stdin);
sprintf(sql, "delete from students where name=\"%s\";", name);
}else if(k == 'q')
break;
printf("\nyou are sure? y or n or q\n");
getchar();
k = fgetc(stdin);
if(k == 'n')
continue;
else if(k == 'y'){
if(mysql_query(&mysql, sql)){
printf("delete failed: %d--%s\n", mysql_errno(&mysql), mysql_error(&mysql));
continue;
}
printf("delete sucess\n");
}
else if(k == 'q')
break;
}
mysql_close(&mysql);
return ;
} int inquiry_student(void)
{
MYSQL mysql;
MYSQL_RES *res;
MYSQL_ROW row;
MYSQL_FIELD *filed; char sql[];
char id[], name[];
char k; int column,i; my_ulonglong backrows; mysql_init(&mysql);
if(!mysql_real_connect(&mysql, "localhost", "root",NULL,"school_db",,NULL,)){
printf("ERROR: %d--%s\n", mysql_errno(&mysql), mysql_error(&mysql));
exit(-);
}
mysql_set_character_set(&mysql, "utf8"); while(){
printf("please input you want inquiry student id or name, selset i or n or q\n");
getchar(); //标记
k = fgetc(stdin);
if(k == 'i') {
printf("student id: ");
scanf("%s", id);
//fgets(id, 10, stdin);
sprintf(sql, "select * from students where student_id=\"%s\";", id);
printf("sql request:%s\n", sql);
}else if(k == 'n') {
printf("\nstudent name: ");
scanf("%s", name);
//fgets(name, 20, stdin);
sprintf(sql, "select * from students where name=\"%s\";", name);
printf("sql request:%s\n", sql);
}else if(k == 'q')
break;
printf("\nyou are sure? y or n or q\n");
getchar();
k = fgetc(stdin);
if(k == 'n')
continue;
else if(k == 'y'){
if(mysql_query(&mysql, sql)){
printf("delete failed: %d--%s\n", mysql_errno(&mysql), mysql_error(&mysql));
continue;
} res = mysql_store_result(&mysql); //首先判断res是否为NULL来判断是否有数据，但是失败了，不知道为什么，最后用了下面函数
backrows = mysql_num_rows(res);//返回上面函数返回结果的行数 if(backrows != ){
column = mysql_num_fields(res); while((row = mysql_fetch_row(res))){
i = ;
while((filed = mysql_fetch_field(res)) != NULL && (i < column)){
printf("%s:", filed->name);
printf("%s", row[i++]);
printf("\n");
}
printf("\n");
} }else{
printf("no data found\n");
continue;
} printf("inquiry sucess\n");
}
else if(k == 'q')
break;
}
mysql_close(&mysql);
return ;
}
3.编译
gcc -o students students.c -I /usr/include/mysql/ -L /usr/lib/mysql/ -lmysqlclient -lcurses
三：运行现象
最后选择Q退出整个系统
虽然所要求的功能基本实现，但是比预先心里所想的还有许多差距，看看程序就知道，改了有改，确实没时间了，就这样吧。
