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(10) not null, sex char(4) not null, birth date not null, politily char(20) not null ); insert into students values (201080701,"张三","男","1994-12-2","自动化1"); insert into students values (201080702,"李四","男","1989-10-8","自动化2"); insert into students values (201080703,"王五","男","1994-8-8","自动化2"); insert into students values (201080704,"路人1","女","1994-7-9","自动化2"); insert into students values (201080705,"路人2","男","1994-12-8","自动化2"); insert into students values (201080706,"路人3","女","1994-11-8","自动化2"); insert into students values (201080707,"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[20]; char passwd[20]; char c; int i; printf("*********************************************************** "); printf("* welcome to student information managent system * "); printf("*********************************************************** "); // printf(" user: ______________ "); // printf(" psaawd:______ "); while(1){ printf(" user:"); scanf("%s", user); printf(" passwd:"); scanf("%s",passwd); /* while ((c=getch())!=' ') { 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=='') { --i; putchar(''); putchar(' '); putchar(''); } } putchar(' '); passwd[i] = ' '; */ if(!strncmp(user, "qigaohua", 8)){ if(!strncmp(passwd, "123456", 6)) break; else { printf("passwd error "); continue; } }else{ printf("user error "); continue; } } printf("login sucess "); while(1){ 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 0; break; default: ; } } printf("exit sucess "); return 0; } /*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())!=' ') { 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=='') { --i; putchar(''); putchar(' '); putchar(''); } } putchar(' '); passwd[i] = ' '; return passwd; }*/ void printf_mune(void) { printf("The following operations can be performed "); printf("1. insert student information input I "); printf("2. delete student information input D "); printf("3. inquiry student information input S "); printf("4. exit student information managent system input Q "); } int insert_student(void) { MYSQL mysql; char sql[100]; char k; char id[10], name[20], sex[5],birth[15],potility[20]; mysql_init(&mysql); if(!mysql_real_connect(&mysql, "localhost", "root",NULL,"school_db",0,NULL,0)){ printf("ERROR: %d--%s ", mysql_errno(&mysql), mysql_error(&mysql)); exit(-1); } mysql_set_character_set(&mysql, "utf8"); while(1) { printf("please input student information "); printf("student_id: "); fflush(stdin); scanf("%s",id); // fgets(id, 10, stdin); printf(" name: "); scanf("%s",name); // fgets(name, 20, stdin); printf(" sex: "); scanf("%s",sex); printf(" birth: "); scanf("%s",birth); // fgets(birth, 15, stdin); printf(" politily: "); scanf("%s",potility); // fgets(potility, 20, stdin); printf(" please input y or n or q "); // 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(" %s",sql); if(mysql_query(&mysql, sql)){ printf(" insert failed: %d--%s ", mysql_errno(&mysql), mysql_error(&mysql)); continue; } printf(" insert sucess "); printf("you want exit? input q "); getchar(); k = fgetc(stdin); if(k == 'q') break; } } mysql_close(&mysql); return 0; } int delete_student(void) { MYSQL mysql; char sql[100]; char id[10], name[20]; char k; mysql_init(&mysql); if(!mysql_real_connect(&mysql, "localhost", "root",NULL,"school_db",0,NULL,0)){ printf("ERROR: %d--%s ", mysql_errno(&mysql), mysql_error(&mysql)); exit(-1); } mysql_set_character_set(&mysql, "utf8"); while(1){ printf("please input you want delete student id or name, selset i or n or q "); 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(" student name: "); scanf("%s",name); //fgets(name, 20, stdin); sprintf(sql, "delete from students where name="%s";", name); }else if(k == 'q') break; printf(" you are sure? y or n or q "); getchar(); k = fgetc(stdin); if(k == 'n') continue; else if(k == 'y'){ if(mysql_query(&mysql, sql)){ printf("delete failed: %d--%s ", mysql_errno(&mysql), mysql_error(&mysql)); continue; } printf("delete sucess "); } else if(k == 'q') break; } mysql_close(&mysql); return 0; } int inquiry_student(void) { MYSQL mysql; MYSQL_RES *res; MYSQL_ROW row; MYSQL_FIELD *filed; char sql[100]; char id[10], name[20]; char k; int column,i; my_ulonglong backrows; mysql_init(&mysql); if(!mysql_real_connect(&mysql, "localhost", "root",NULL,"school_db",0,NULL,0)){ printf("ERROR: %d--%s ", mysql_errno(&mysql), mysql_error(&mysql)); exit(-1); } mysql_set_character_set(&mysql, "utf8"); while(1){ printf("please input you want inquiry student id or name, selset i or n or q "); 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 ", sql); }else if(k == 'n') { printf(" student name: "); scanf("%s", name); //fgets(name, 20, stdin); sprintf(sql, "select * from students where name="%s";", name); printf("sql request:%s ", sql); }else if(k == 'q') break; printf(" you are sure? y or n or q "); getchar(); k = fgetc(stdin); if(k == 'n') continue; else if(k == 'y'){ if(mysql_query(&mysql, sql)){ printf("delete failed: %d--%s ", 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 != 0){ column = mysql_num_fields(res); while((row = mysql_fetch_row(res))){ i = 0; while((filed = mysql_fetch_field(res)) != NULL && (i < column)){ printf("%s:", filed->name); printf("%s", row[i++]); printf(" "); } printf(" "); } }else{ printf("no data found "); continue; } printf("inquiry sucess "); } else if(k == 'q') break; } mysql_close(&mysql); return 0; }
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。