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：
