首先给树莓派安装 sqlites3
sudo apt-get install sqlite3在安装C/C++ sqlite3 中相关的库
sudo apt-get install libsqlite3-dev编译文件的时候记得带上 -lsqlite3
详细的SQL语法百度和参考菜鸟教程中sqlite3
sqlite3中基本操作
创建或打开数据库
1.sqlite3 test.db
创建一个表
2.create table xixi(sid,sun)values(1,”1212”);
插入数据
3.insert into xixi(sid,sun)values(2,’1234’);
修改数据
4.update xixi set sun=’gululu’ where sid=1;
查找数据
5.select * from xixi;
退出数据库
6. .exit
C/C++ 例子
#include <stdio.h>
#include <stdlib.h>
#include <sqlite3.h>
#include <string.h>
#include <time.h>
#include "shujuku.h"
#define _debug_
int main( void )
{
unsigned char card_num[4];
int i=0;
char hanshu[10];
int flag=0;
time_t timep;
time (&timep);
// input_sql(card_num);
// findsql(card_num);
while(1)
{
scanf("%d",&flag);
switch(flag){
case 1:
{ printf("please find card_num:\n");
for(i=0;i<4;){
printf("please input card_num[%d]:",i);
if(scanf("%hhx",&card_num[i]))i++;
}
if(findsql(card_num)==0)printf("no card!\n");
flag=0;
break;
}
case 2:
{
printf("please insert card_num:\n");
for(i=0;i<4;){
printf("please input card_num[%d]:",i);
if(scanf("%hhx",&card_num[i]))i++;
}
if(findsql(card_num)==0)printf("can be inserted to sql!\n");
time (&timep);
printf( "%s ",ctime(&timep));
input_sql(card_num);
time (&timep);
printf( "%s ",ctime(&timep));
printf("gg\n");
flag=0;
break;
}
default:
break;
}
}
// select_sql();
// getcount_sql(hanshu);
// printf("%s\n",hanshu);
return 0;
}
int wf_callback(void *arg, int nr, char **values, char **names)
{
int i;
FILE *fd;
char str[200];
fd = (FILE *)arg; //将void *的参数强制转换为FILE *
for (i=0; i<nr; i++) { //将查询结果写入到文件中
memset(str, '\0', 200);
sprintf(str, "%s", values[i]);
fwrite(str, sizeof(char), sizeof(str), fd);
}
memset(str, '\0', 200);
fwrite("\n", sizeof(char), 2, fd); //写完一条记录换行
return 0; //callback函数正常返回0
}
//得到行数
int getcount_sql(char *max_count){
sqlite3 *db=NULL;
char *zErrMsg = 0;
int rc;
int jieguo=0;
char **azResult=NULL; //二维数组存放结果
int nrow=0;
int ncolumn = 0;
int i;
rc = sqlite3_open("/home/pi/sql/test.db", &db);
if( rc ) {
fprintf(stderr, "Can't open database: %s/n", sqlite3_errmsg(db));
sqlite3_close(db);
return 1;
}
//jieguo=sqlite3_exec(db, get_count, NULL, NULL, NULL);
sqlite3_get_table( db , get_count , &azResult , &nrow , &ncolumn ,NULL );
#ifdef _debug_
printf( "row:%d column=%d\n " , nrow , ncolumn );
for( i=0 ; i<( nrow + 1 ) * ncolumn ; i++ )
{
printf( "azResult[%d] = %s\n", i , azResult[i] );
}
#endif
memset(max_count,0,10*sizeof(unsigned char));
sprintf(max_count,"%s\0",azResult[1]);
sqlite3_free_table(azResult);
sqlite3_close(db); //关闭数据库
}
//查找数据
int select_sql(){
sqlite3 *db=NULL;
char *zErrMsg = 0;
int rc;
FILE *fd;
fd = fopen("/home/pi/sql/shuju.txt", "w");
rc = sqlite3_open("/home/pi/sql/test.db", &db);
if( rc ) {
fprintf(stderr, "Can't open database: %s/n", sqlite3_errmsg(db));
sqlite3_close(db);
return 1;
}
sqlite3_exec(db, selsql, wf_callback, fd, NULL);
fclose(fd);
sqlite3_close(db); //关闭数据库
}
//查找某个数据 数组中
int findsql(unsigned char *num){
unsigned char card[9] ;
char sql[300];
sqlite3 *db=NULL;
char *zErrMsg = 0;
int rc;
int i;
char **azResult=NULL; //二维数组存放结果
int nrow=0;
int ncolumn = 0;
chage(num, card, 4);
char *str = (char *)card;
//打开指定的数据库文件,如果不存在将创建一个同名的数据库文件
rc = sqlite3_open("/home/pi/sql/test.db", &db);
if( rc )
{
fprintf(stderr, "Can't open database: %s/n", sqlite3_errmsg(db));
sqlite3_close(db);
return 1;
}
sprintf(sql,"%s%s%s","select sid from xixi where card ='",str,"';");
sqlite3_get_table( db , sql , &azResult , &nrow , &ncolumn ,NULL );
#ifdef _debug_
printf( "row:%d column=%d\n " , nrow , ncolumn );
for( i=0 ; i<( nrow + 1 ) * ncolumn ; i++ )
{
printf( "azResult[%d] = %s\n", i , azResult[i] );
}
#endif
if((nrow==0)&&(ncolumn==0)){
printf("no the same date!");
return 0;
}
return 1;
}
//插入数据
int input_sql(unsigned char *num){
unsigned char card[9] ;
char sql[300];
sqlite3 *db=NULL;
char *zErrMsg = 0;
int rc;
int i;
int jieguo=0;
chage(num, card, 4);
char *str = (char *)card;
//打开指定的数据库文件,如果不存在将创建一个同名的数据库文件
rc = sqlite3_open("/home/pi/sql/test.db", &db);
if( rc )
{
fprintf(stderr, "Can't open database: %s/n", sqlite3_errmsg(db));
sqlite3_close(db);
return 1;
}
//删除最开始的数据
sprintf(sql, "%s", "delete from xixi where sid = 1; ");
sqlite3_exec(db, sql, NULL, NULL, NULL);
//更新999次数据
for(i=1;i<=499;i++){
memset(sql, '\0', 300);
sprintf(sql, "%s%d%s%d%s", "update xixi set sid =", i," where sid = ",i+1,";");
sqlite3_exec(db, sql, NULL, NULL, NULL);
}
//插入最后的数据
memset(sql, '\0', 300);
sprintf(sql, "%s%s%s","insert into xixi(sid,card)values(500,'",str,"');");
sqlite3_exec(db, sql, NULL, NULL, NULL);
//关闭数据库
sqlite3_close(db);
}
//数组装换成字符串
void chage(const unsigned char *card_num, unsigned char *card_string,int len)
{
int i;
char S_num[3];
for (i = 0; i < len; ++i) {
sprintf(S_num,"%02x", card_num[i]);
memcpy(&card_string[i * 2], S_num, 3);
}
}
select_sql();
中添加了回调函数，回调函数会将读到的相关的数据全部写入到文件中，这样可以在文件中查看。
参考：
https://www.cnblogs.com/lzjsky/p/3688324.html
https://www.cnblogs.com/bluestorm/archive/2011/10/25/2298127.html