一、数据库

        sqlite官网：www.sqlite.org

1.1 数据库的安装

        离线安装：

        sudo dpkg -i sqlite3_3.22.0-1ubuntu0.4_amd64.deb //数据库软件

        sudo dpkg -i libsqlite3-dev_3.22.0-1ubuntu0.4_amd64.deb //数据库的库函数

        在线安装：

        sudo apt-get install sqlite3 libsqlite3-dev

        如何确定自己是否已经安装成功了？

        在终端输入 sqlite3 如果能进入到下面的界面说明安装成功了

代码实现：

01test.c

gcc 01test.c -lsqlite3

编译时，需要链接sqlite3的库 -lsqlite3

#include <stdio.h>
#include <sqlite3.h>
#include <unistd.h>
#include <stdlib.h>
sqlite3 *pro_init()
{
    sqlite3 *my_db = NULL;
    int ret = 0;
    char *errmsg = NULL;
    if (SQLITE_OK != (ret = sqlite3_open("test.db", &my_db)))
    {
        printf("sqlite3_open error:errno = [%d],errstr = [%s]\n", ret, sqlite3_errmsg(my_db));
        exit(-1);
    }
    printf("打开数据库成功...\n");
    // 建表
    // IF NO EXISTS表示如果不存在就新建  如果存在 就直接使用
    char sqlbuff[256] = "CREATE TABLE IF NOT EXISTS student(id INT PRIMARY KEY,name TEXT,score INT)"; // 程序中使用sql语句结尾不必加分号
    printf("%s\n", sqlbuff);
    if (SQLITE_OK != (ret = sqlite3_exec(my_db, sqlbuff, NULL, NULL, &errmsg)))
    {
        printf("sqlite3_exec error:errno = %d,errstr = %s\n", ret, errmsg);
        exit(-1);
    }
    printf("建表成功..\n");
    sqlite3_free(errmsg); // 如果使用了第5个参数需要手动释放空间
    return my_db;
}
void print_menu()
{
    printf("--------------------------------------------\n");
    printf("| 1.添加   2.查找   3.修改   4.删除   5.退出 |\n");
    printf("--------------------------------------------\n");
    printf("请输入您的选择:");
}
// 添加学员信息
void insert_student(sqlite3 *my_db)
{
    int input_id = 0;
    int input_score = 0;
    char input_name[32] = {0};
    int ret = 0;
    printf("请输入学员信息(id(int) name(char) score(int)):");
    scanf("%d%s%d", &input_id, input_name, &input_score);
    // 组装sql语句
    char sqlbuff[256] = {0};
    sprintf(sqlbuff, "INSERT INTO student VALUES(%d,'%s',%d)", input_id, input_name, input_score);
    printf("sqlbuff : [%s]\n", sqlbuff);
    // 执行sql语句
    if (SQLITE_OK != (ret = sqlite3_exec(my_db, sqlbuff, NULL, NULL, NULL)))
    {
        printf("sqlite3_exec error:errno = %d,errstr = %s\n", ret, sqlite3_errmsg(my_db));
        exit(-1);
    }
    printf("学员信息添加成功...\n");
    return;
}
// 查找学员信息 使用sqlite3_get_table实现
void search_student(sqlite3 *my_db)
{
    int ret = 0;
    char **result = NULL;
    int row = 0;
    int column = 0;
    // 组装sql语句
    char sqlbuff[256] = "SELECT *FROM student";
    // 执行sql语句
    if (SQLITE_OK != (ret = sqlite3_get_table(my_db, sqlbuff, &result, &row, &column, NULL)))
    {
        printf("sqlite3_get_table error: errno = [%d],errstr = [%s]\n", ret, sqlite3_errmsg(my_db));
        exit(-1);
    }
    // 先打印字段名
    int i = 0;
    int j = 0;
    for (int i = 0; i < column; i++)
    {
        printf("%16s", result[i]);
    }
    printf("\n");
    int index = i;
    // 再打印字段值
    for (i = 0; i < row; i++)
    {
        for (j = 0; j < column; j++)
        {
            printf("%16s", result[(i + 1) * 3 + j]);
        }
        printf("\n");
    }
    printf("学员信息查询成功...\n");
    return;
}
void modify_student(sqlite3 *my_db)
{
    printf("请输入要修改的学员id:");
    int input_id = 0;
    scanf("%d", &input_id);
    char input_name[32] = {0};
    int input_score = 0;
    printf("请输入新学员的信息(name(char) score(int)):");
    scanf("%s%d", input_name, &input_score);
    int ret = 0;
    char sqlbuff[256] = {0};
    sprintf(sqlbuff, "UPDATE student SET name='%s',score=%d WHERE id=%d", input_name, input_score, input_id);
    // 执行sql语句
    if (SQLITE_OK != (ret = sqlite3_exec(my_db, sqlbuff, NULL, NULL, NULL)))
    {
        printf("sqlite3_exec error:errno = %d,errmsg = %s\n", ret, sqlite3_errmsg(my_db));
        exit(-1);
    }
    printf("修改学员信息成功...\n");
    return;
}

void del_student(sqlite3 *my_db)
{
    printf("请输入要删除的学员id:");
    int input_id = 0;
    scanf("%d", &input_id);
    // 组装sql语句
    char sqlbuff[256] = {0};
    int ret = 0;
    sprintf(sqlbuff, "DELETE FROM student where id=%d", input_id);
    // 执行sql语句
    if (SQLITE_OK != (ret = sqlite3_exec(my_db, sqlbuff, NULL, NULL, NULL)))
    {
        printf("sqlite3_exec error:errno = %d,errmsg = %s\n", ret, sqlite3_errmsg(my_db));
        exit(-1);
    }
    printf("学员信息删除成功...\n");
    return;
}
int main(int argc, char const *argv[])
{
    printf("欢迎使用..\n");
    sqlite3 *my_db = NULL;
    my_db = pro_init();
    int choose = 0;
    while (1)
    {
        print_menu();
        scanf("%d", &choose);
        switch (choose)
        {
        case 1:
            insert_student(my_db);
            break;
        case 2:
            search_student(my_db);
            break;
        case 3:
            modify_student(my_db);
            break;
        case 4:
            del_student(my_db);
            break;
        }
        if (5 == choose)
        {
            printf("退出成功..\n");
            break;
        }
    }
    sqlite3_close(my_db);
    printf("欢迎下次使用...\n");
    return 0;
}

 效果图：