通過這幾天學習Mysql數據庫，對其也有了基本的了解，為了加深印象，於是就寫了一個最簡易的學生信息管理系統。
一：基本要求
1.通過已知用戶名和密碼進行登錄；
2.可以顯示菜單；
3.可以隨時插入學生信息；
4.可以刪除學生信息；
5.可以通過學生姓名或學號顯示學生所有信息；
還可以修改學生信息，添加學生表格屬性等等，，，這些實現都基本類似上述的（這些不想寫了，最簡易的學生信息管理系統）；
二：步驟
1.寫一個sql腳本，包括創建數據庫，使用數據庫，創建學生信息表格，插入大部分學生信息。
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,"張三","男","1994-12-2","自動化1"); insert into students values (201080702,"李四","男","1989-10-8","自動化2"); insert into students values (201080703,"王五","男","1994-8-8","自動化2"); insert into students values (201080704,"路人1","女","1994-7-9","自動化2"); insert into students values (201080705,"路人2","男","1994-12-8","自動化2"); insert into students values (201080706,"路人3","女","1994-11-8","自動化2"); insert into students values (201080707,"路人4","男","1992-1-23","自動化2");
。。。。
執行腳本：
第一種方法： mysql -h localhost -u root -p 密碼 < student_information.sql;
第二種方法：已經登錄了mysql， source student_information.sql；
2.編寫代碼
#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("***********************************************************\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(1){ printf(" user:"); scanf("%s", user); printf(" passwd:"); scanf("%s",passwd); /* while ((c=getch())!='\n') { if (i<MAX_PASSWD_LEN && isprint(c)) //isprint函數判斷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", 8)){ if(!strncmp(passwd, "123456", 6)) break; else { printf("passwd error\n"); continue; } }else{ printf("user error\n"); continue; } } printf("login sucess\n"); while(1){ printf_mune(); getchar(); //問題1 必須加 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\n"); return 0; } /*getc()和getchar()函數想必大家都經常用到，但它們都在輸入的同時顯示輸入內容，並由回車終止輸入。 為了不顯示輸入內容，我們調用另外一個函數getch()，它包含在頭文件中。該函數可以在輸入的同時不顯示 輸入內容，並在輸入完成后不需回車而自動終止輸入。與此同時，該頭文件中還包含另外一個函數getche()， 它和getch()功能相同，唯一的區別是輸入的同時顯示輸入的內容。本文我們只用到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函數判斷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[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\n", mysql_errno(&mysql), mysql_error(&mysql)); exit(-1); } mysql_set_character_set(&mysql, "utf8"); while(1) { 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 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\n", 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\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 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\n", 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\n"); getchar(); //標記 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); //首先判斷res是否為NULL來判斷是否有數據，但是失敗了，不知道為什么，最后用了下面函數 backrows = mysql_num_rows(res);//返回上面函數返回結果的行數 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("\n"); } printf("\n"); } }else{ printf("no data found\n"); continue; } printf("inquiry sucess\n"); } else if(k == 'q') break; } mysql_close(&mysql); return 0; }
3.編譯
gcc -o students students.c -I /usr/include/mysql/ -L /usr/lib/mysql/ -lmysqlclient -lcurses
三：運行現象
最后選擇Q退出整個系統
雖然所要求的功能基本實現，但是比預先心里所想的還有許多差距，看看程序就知道，改了有改，確實沒時間了，就這樣吧。