2.DB-Mysql++实例

以下为自己写过的测试代码，确认OK

以下为自己的数据库：

遍历查询代码

#include "stdafx.h"
#include <iostream>
#include <string>
#include <cstdlib>
#include <mysql++.h>
using std::cout;
using std::endl;

#ifdef _DEBUG
#pragma comment(lib, "..\\debug\\mysqlpp.lib")
#else
#pragma comment(lib, "..\\release\\mysqlpp.lib")
#endif

int _tmain(int argc, _TCHAR* argv[])
{
const char* db = "ppdb", *server = "192.168.75.129", *user = "root", *pass = "123456";
mysqlpp::Connection conn(false);	// 连接数据库
if (conn.connect(db, server, user, pass))
{
// 从ppdb表中获取所有字段数据表并显示
mysqlpp::Query query = conn.query("select * from ppdb_resources");
if (mysqlpp::StoreQueryResult res = query.store())
{
std::cout << "We have:" << std::endl;
for (size_t i = 0; i < res.num_rows(); ++i)
{
for (size_t j=0; j < res.num_fields(); ++j)
{
mysqlpp::String temp = res[i][j];
cout << '\t' << temp;
}
cout <<endl;
}
}
else
{
std::cout << "Failed to get item list: " << query.error() << endl;
}
}

getchar();
return 0;
}

注意，你想获取第5列第2行的数据，你可以这样写 res[1][4]

另blob数据同样是存在String结构中的，它是一个类似驱动unicode_string的结构体，使用len+buf

通过下标查询代码

把上面的for循环可以改成：只查询res_name这一列的，我们使用对象字段标示进行访问，而不再使用下标。这样做会略微慢一些，但是可读性很好

for (size_t i = 0; i < res.num_rows(); ++i)
{
mysqlpp::String temp = res[i]["res_name"];
cout << '\t' << temp;
}

使用输入流查询

mysqlpp::Query query(&conn);
std::string cmd_only = "res_name";
query<<"select res_name from ppdb_resources";
if (mysqlpp::StoreQueryResult res = query.store())
{
for (size_t i = 0; i < res.num_rows(); ++i)
{
mysqlpp::String temp = res[i][0];
cout << '\t' << temp;
}
}

绑定BLOB数据

插入一行数据

const char* db = "ppdb", *server = "192.168.75.129", *user = "root", *pass = "123456";
mysqlpp::Connection con;
con.connect(db, server, user, pass);
Query query = con.query();
char *pbuf = new char[10];memset(pbuf,0x10,10);
string img_data;img_data.assign(pbuf,10);
// INSERT INTO ppdb_resources(res_file,res_name,res_desc,res_hash,res_size,res_seed,res_piece,res_stamp) VALUES('SecureFXPortable.exe','SecureFXPortable.exe','',?,69553,?,1,UNIX_TIMESTAMP())
query << "INSERT INTO ppdb_resources(res_file,res_name,res_desc,res_hash,res_size,res_seed,res_piece,res_stamp) VALUES('SecureFXPortable.exe','SecureFXPortable.exe','',\""
<< mysqlpp::escape << img_data <<"\",69553,\""
<< mysqlpp::escape << img_data <<"\",1,UNIX_TIMESTAMP())";
SimpleResult res = query.execute();

特别注意<< mysqlpp::escape << img_data <<前后都要使用"\", 说得更明白点，就是blob前后必须加上""

res.copacetic_ = true表示执行成功

更新blob数据

// UPDate
query << "update ppdb_resources set res_seed =\""
<<mysqlpp::escape << img_data <<"\"where res_uid=76";
SimpleResult res = query.execute();

读取bolb数据

mysqlpp::Query query = conn.query("select res_hash from ppdb_resources where res_uid=79");
mysqlpp::StoreQueryResult res = query.store();
if (res)
{
mysqlpp::sql_blob_null blob = res[0][0];
int iLength = blob.data.length();
const char* p = blob.data.data();
printf("%s",p);
}

SSQLS

sql_create_9(ppdb_resources,
1, 9,
mysqlpp::sql_int_unsigned, res_uid,
mysqlpp::sql_varchar,		res_file,
mysqlpp::sql_varchar,		res_name,
mysqlpp::sql_varchar_null, res_desc,
mysqlpp::sql_tinyblob,		res_hash,
mysqlpp::sql_int,			res_size,
mysqlpp::sql_mediumblob,	res_seed,
mysqlpp::sql_int,			res_piece,
mysqlpp::sql_bigint,		res_stamp);

int _tmain(int argc, _TCHAR* argv[])
{
const char* db = "ppdb", *server = "192.168.75.129", *user = "root", *pass = "123456";
mysqlpp::Connection conn(false);	// 连接数据库
if (conn.connect(db, server, user, pass))
{
String data;
char *pBuf = new char[20];
memset(pBuf,0x20,20);
data.assign(pBuf,20);
Query query = conn.query("select res_hash from ppdb_resources where res_uid=10");
mysqlpp::StoreQueryResult res = query.store();
if (res)
{
ppdb_resources row = res[0];
ppdb_resources orig_row = row;
row.res_hash = data;
query.update(orig_row, row);
SimpleResult res = query.execute();
res;
}
}

String data;
char *pBuf = new char[20];
memset(pBuf,0x20,20);
data.assign(pBuf,20);

ppdb_resources img(10, "insert.exe","insert.exe",
mysqlpp::null,data,
12345,data,15,1234567841);
Query query = conn.query();
query.insert(img);
SimpleResult res = query.execute();