思维导图

数据库

#include <myhead.h>
//添加学生信息
void insert_stu(sqlite3* sq,char* errMsg)
{
    char text[128];
    int ID,age,height;
    char name[10];
    scanf("%d%s%d%d",&ID,name,&age,&height);
    sprintf(text,"insert into Student values (%d,'%s',%d,%d)",ID,name,age,height);
    sqlite3_exec(sq,text,NULL,NULL,&errMsg);
}
//更新学生信息
void update_stu(sqlite3* sq,char* errMsg)
{
    char text[128];
    int IDs;
    char old[10],new[10];
    printf("请输入要修改的学生的学号:");
    scanf("%d",&IDs);
    printf("请输入要修改的学生的信息:");
    scanf("%s",old);
    printf("请输入新的该学生信息:");
    scanf("%s",new);

    if(strcmp(old,"name")==0)
    {
        sprintf(text,"update Student set name='%s' where ID=%d",new,IDs);
        sqlite3_exec(sq,text,NULL,NULL,&errMsg);
        printf("修改成功\n");
    }
    else if(strcmp(old,"age")==0)
    {
        sprintf(text,"update Student set age=%s where ID=%d",new,IDs);
        sqlite3_exec(sq,text,NULL,NULL,&errMsg);
        printf("修改成功\n");
    }
    else if(strcmp(old,"height")==0)
    {
        sprintf(text,"update Student set height=%s where ID=%d",new,IDs);
        sqlite3_exec(sq,text,NULL,NULL,&errMsg);
        printf("修改成功\n");
    }
    else
    {
        printf("输入不合法\n");
    }
}
//删除学生
void delete_stu(sqlite3* sq,char* errMsg)
{
    int id;
    char text[128];
    printf("请输入要删除的学生学号:");
    scanf("%d",&id);
    sprintf(text,"delete from Student where ID=%d",id);
    sqlite3_exec(sq,text,NULL,NULL,&errMsg);
    printf("删除成功\n");
}

int main(int argc, char const *argv[])
{
    //创建数据库
    sqlite3 *sq = NULL;
    if(sqlite3_open("./mysq.db",&sq)!=0)
    {
        printf("打开失败\n");
    }
    printf("打开成功\n");

    //创建学生表
    char *errMsg = 0;
    char sql[128]="create table if not exists Student(ID int,name char,age int,height int);";
    int rc = sqlite3_exec(sq,sql,NULL,NULL,&errMsg);
    printf("%d\n",rc);
    if(rc != SQLITE_OK)
    {
        perror("exec");
        return -1;
    }    

    while(1)
    {
        int a = 0;
        printf("------1添加学生信息-----\n");
        printf("------2删除学生信息-----\n");
        printf("------3修改学生信息-----\n");
        scanf("%d",&a);
        switch(a)
        {
            case 1:insert_stu(sq,errMsg);break;
            case 2:delete_stu(sq,errMsg);break;
            case 3:update_stu(sq,errMsg);break;
            default:printf("请重新输入\n");
        }
        
    }

    return 0;
}