数据库设置：
用mediumBlob 是由于在mysql中 ： MYSQL 有四种类型的来存储文件,其区别就在于存储文件的大小 TinyBlob ：255，BLOB :65k ，MediumBlob : 16M，Longlob : 4G。 这样可以存储多的文件。但是仅这样还不够，因为mysql默认的存储比较小，需要修改max_allowed_packet的值，修改方法如下：
mysql>show variables like 'max_allowed_packet';
出现了默认值为1048576 可能会有不同的，但是通常会小
修改： mysql > SET @@global.max_allowed_packet = 16777216; 设置为16M。
#include <zlib.h>
#include<stdio.h>
#include <string.h>
#include "mmysql.h"
#include <sys/stat.h>
#include<sys/types.h>
#include <string>
int get_file_size(char *path, off_t *size) {
struct stat file_stats;
if (stat(path, &file_stats))
return -1;
*size = file_stats.st_size;
return 0;
}
int main() {
char *filename;
off_t size;
filename = (char*)"png_2.png";
if ((get_file_size(filename, &size)) == -1) {
perror("get file size");
return 1;
}
char *sql;
//char *end;
char *buf;
FILE *fp;
int n = 0;
if ((buf = (char *) malloc(sizeof(char) * (size + 1))) == NULL) {
perror("malloc buf");
return 1;
}
if ((fp = fopen(filename, "rb")) == NULL) {
perror("fopen file");
return 1;
}
if ((n = fread(buf, 1, size, fp)) < 0) { //n=*size
perror("fread file");
return 1;
}
sql = (char *) malloc(sizeof(char) * n * 2 + 256); //2n+1+strlen(other sql)
if (sql == NULL) {
perror("malloc sql");
return 1;
}
mmysql *pInstall = mmysql::makeInstall();
pInstall->mysql_connect("root", "nyy123456", "uwb");
char * b_s;
b_s=pInstall->ConvertBinaryToString( buf, n);
char mysql[] = "insert into uwb_map (id, map_name, map_data) values(null, 'peter','%s')";
sprintf(sql, mysql,b_s);
pInstall->mysql_insert(sql, strlen(sql));
return 1;
}
/*************************************************************************
> File Name: mysql.cpp
> Author: mouse
> Mail: [email protected]
> Created Time: Tue 07 Nov 2017 04:19:27 PM CST
************************************************************************/
#include "mmysql.h"
#include <iostream>
#include <cstring>
#include<string>
#include <sstream>
//#include </usr/include/mysql/mysql.h>
#include <mysql/mysql.h>
using namespace std;
mmysql* mmysql::pInstall = new mmysql();
mmysql::mmysql() {
this->dbHandle = mysql_init(NULL);
}
mmysql::~mmysql() {
mysql_close(this->dbHandle);
}
mmysql* mmysql::makeInstall() {
return pInstall;
}
void mmysql::mysql_connect(const char* user, const char* passwd,
const char* dbname) {
if (mysql_real_connect(this->dbHandle, "localhost", user, passwd, dbname, 0,
NULL, 0)) {
cout << "连接成功" << endl;
// 设置编码
mysql_query(dbHandle, "set names utf8");
} else {
this->erron = 1;
}
}
float mmysql::float_to_float(float f, int bits) {
stringstream ss;
ss << fixed << setprecision(bits) << f;
ss >> f;
return f;
}
int mmysql::mysql_querys2(const char* query){
if (mysql_real_query(this->dbHandle, query, strlen(query))) {
this->erron = 2;
} else {
MYSQL_RES *result = mysql_store_result(this->dbHandle);
if (result) {
for (int i = 0; i < mysql_num_rows(result); i++) {
MYSQL_ROW row = mysql_fetch_row(result);
for (int j = 0; j < mysql_num_fields(result); j++) {
//printf("%s\t", row[j]);
cout << "--" << row[j]<<endl;
}
cout << "\n"<<endl;
}
}
mysql_free_result(result);
}
}
int mmysql::mysql_querys(const char* query, unsigned char * cValue) {
int n=0;
float xyz[6000];
if (mysql_real_query(this->dbHandle, query, strlen(query))) {
this->erron = 2;
} else {
MYSQL_RES *result = mysql_store_result(this->dbHandle);
if (result) {
for (int i = 0; i < mysql_num_rows(result); i++) {
MYSQL_ROW row = mysql_fetch_row(result);
for (int j = 0; j < mysql_num_fields(result); j++) {
if (j == 2 || j == 3 || j == 4) {
float f = atof(row[j]);
xyz[n] = float_to_float(f, 2);
n=n+1;
}
//printf("%s\t", row[j]);
}
//printf("\n");
}
printf("---所有的浮点数个数： %d---------- \n", n);
for (int m = 0; m < n; m++) {
unsigned char *fValue = (unsigned char *) &xyz[m];
for(int i=0;i<4;i++){
memcpy(cValue + m*4+i, &fValue[i], 1);
}
}
}
mysql_free_result(result);
}
return n*4;
}
void mmysql::mysql_insert(const char *cmd,unsigned int l) {
cout << "Database ++++++" << endl << endl;
if (NULL == cmd) {
cout << "[insert] cmd error" << endl;
}
if (mysql_real_query(this->dbHandle, cmd,l)) {
this->erron = 3;
} else {
cout << "Database Insert Info: exist, I am updata." << endl << endl;
}
}
//int to string
/*string mmysql:: inttostring(int in)
{
stringstream ss;
string str;
ss << in;
ss >> str;
return str;
}*/
char* mmysql::ConvertBinaryToString(char* pBinaryData,int nLen)
{
static char * s_BinaryData=(char *) malloc(sizeof(char) * nLen * 2 + 256);
mysql_real_escape_string(this->dbHandle,s_BinaryData,pBinaryData,nLen);
return s_BinaryData;
}
void mmysql::mysql_re_string( char *end, char *buf,unsigned long int n){
end+=mysql_real_escape_string(this->dbHandle, end, buf, n);
cout << "-------end:" << *end<< endl;
}
void mmysql::print_error() {
switch (this->erron) {
case 1:
cout << "连接失败" << mysql_error(this->dbHandle) << endl;
break;
case 2:
cout << "查询失败" << mysql_error(this->dbHandle) << endl;
break;
case 3:
cout << "插入数据失败" << mysql_error(this->dbHandle) << endl;
break;
default:
cout << "错误信息不存在" << endl;
break;
}
}
long unsigned int mmysql::mysql_cout() {
return mysql_affected_rows(this->dbHandle);
}
/*void mmysql::mysql_read() {
// 释放数据
if(this->row != NULL) {
for(int i = 0; i < this->cow; i++ ) {
delete[] this->tep[i];
}
delete[] this->tep;
}
MYSQL_RES *result = mysql_store_result(this->dbHandle);
MYSQL_ROW row;
int cow_lenth = result->field_count;
int row_lenth = result->row_count;
// 数据存储
this->tep = new string* [row_lenth];
for( int i=0; i<row_lenth; i++) {
this->tep[i] = new string[cow_lenth];
}
// 行
this->row = row_lenth;
// 列
this->cow = cow_lenth;
for (int i = 0; i < row_lenth; i++) {
row = mysql_fetch_row(result);
for( int j = 0; j < cow_lenth; j++ ) {
this->tep[i][j] = row[j];
}
}
// 释放数据
mysql_free_result(result);
}
/*int main() {
mmysql *pInstall = mmysql::makeInstall();
pInstall->mysql_connect("root", "zjf199694", "test");
pInstall->mysql_querys("select * from test");
pInstall->mysql_read();
pInstall->mysql_querys("select * from test");
for (int i = 0; i < pInstall->row; i++) {
for (int j = 0; j < pInstall->cow; j++) {
cout << pInstall->tep[i][j] << "\t";
}
cout << endl;
}
pInstall->mysql_read();
for (int i = 0; i < pInstall->row; i++) {
for (int j = 0; j < pInstall->cow; j++) {
cout << pInstall->tep[i][j] << "\t";
}
cout << endl;
}
cout << "aaa" << endl;
return 0;
}*/
/*************************************************************************
> File Name: mysql.h
> Author: malingyu
> Mail: [email protected]
************************************************************************/
#ifndef __MMYSQL_H_
#define __MMYSQL_H_
#include <string>
#include <sstream>
#include <iomanip>
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <mysql/mysql.h>
using namespace std;
class mmysql {
public:
static mmysql *pInstall; // 连接事例
MYSQL *dbHandle;
unsigned int erron;// 错误号
public:
static mmysql* makeInstall();
void print_error();// 错误信息
float float_to_float(float f,int bits) ;//浮点数保留两位小数
void mysql_connect(const char* user, const char* passwd, const char* dbname);// mysql连接
int mysql_querys(const char* query,unsigned char * cValue);// sql 查询
char* ConvertBinaryToString(char* pBinaryData,int nLen);
long unsigned int mysql_cout();// 获取更新行数
void mysql_insert(const char *cmd,unsigned int l);
void mysql_re_string( char *end, char *buf,unsigned long int n);
int mysql_querys2(const char* query);
string inttostring(int in);
private:
mmysql();
public:
~mmysql();
};
#endif
