資料庫MySql類庫系列(八)-預處理執行Sql方式的示例
阿新 • • 發佈：2019-02-06
本文是對之前預處理執行Sql方式的示例程式TestDB
首先是資料表定義：
還是一個簡單的賬號表，包括3個欄位：帳號名（最長20個字元，主鍵），賬號密碼（最長20個字元），賬號id（無符號整數，自增欄位）
sql如下：
CREATE TABLE `account` ( `account_name` varchar(20) NOT NULL, `account_key` varchar(20) NOT NULL, `account_id` int(11) unsigned NOT NULL AUTO_INCREMENT, PRIMARY KEY (`account_name`), UNIQUE KEY `account_id_index` (`account_id`) ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
下面演示對這張表，以預處理執行sql的方式，實現增、刪、改、查
首先，實現一個PrepareDBService，繼承DBService
實現4個介面：
// 分別實現增、刪、改、查 bool SelectAccount(const char(&name)[MaxAccountLen], char(&key)[MaxAccountLen], unsigned int& id); bool InsertAccount(const char(&name)[MaxAccountLen], const char(&key)[MaxAccountLen]); bool UpdateAccount(const char(&name)[MaxAccountLen], const char(&key)[MaxAccountLen]); bool DeleteAccount(const char(&name)[MaxAccountLen]);
對應4個操作物件（2種：增刪改對應PrepareOperatorUpdate，查詢對應PrepareOperatorSelect）
// 對應增、刪、改、查四種操作的預處理的繫結引數/繫結結果 void PrepareSelectAccount(); void PrepareInsertAccount(); void PrepareUpdateAccount(); void PrepareDeleteAccount(); // 對應增、刪、改、查四種操作物件 common::db::PrepareOperatorSelect m_select_account; common::db::PrepareOperatorUpdate m_insert_account; common::db::PrepareOperatorUpdate m_update_account; common::db::PrepareOperatorUpdate m_delete_account;
主要的類關係圖如下：
主函式：
1、插入一個賬號，賬號名=Test001，密碼=0000001的賬號
2、更新這個賬號的密碼，改為1111111
3、查詢這個賬號名=Test001的賬號資訊（賬號名，密碼，id），此時密碼應為第2步已經修改後的密碼，如果該表此前沒有插入過記錄，此時id應該為1，每執行一次插入id+1
4、刪除這個賬號名=Test001的賬號
5、再次查詢這個賬號名=Test001的賬號資訊，此時應該沒有對應的資料
執行結果截圖：
DBService的子類實現：
PrepareDBService.h：
#ifndef __PrepareDBService_H__
#define __PrepareDBService_H__
#include "DBService.h"
#include "PrepareOperatorSelect.h"
#include "PrepareOperatorUpdate.h"
class PrepareDBService : public common::db::DBService
{
public:
PrepareDBService();
virtual ~PrepareDBService();
public:
// 最大賬號，密碼字串長度為20個字元
static const unsigned int MaxAccountLen = 20;
public:
virtual bool ProcessStart();
virtual void ProcessStop();
// 分別實現增、刪、改、查
bool SelectAccount(const char(&name)[MaxAccountLen], char(&key)[MaxAccountLen], unsigned int& id);
bool InsertAccount(const char(&name)[MaxAccountLen], const char(&key)[MaxAccountLen]);
bool UpdateAccount(const char(&name)[MaxAccountLen], const char(&key)[MaxAccountLen]);
bool DeleteAccount(const char(&name)[MaxAccountLen]);
private:
// 賬號屬性型別
enum AccountPropertyType
{
account_name = 0, // 帳號名稱
account_key, // 賬號密碼
account_id, // 賬號id
account_property_count,
};
unsigned long m_property_len[account_property_count];
void InitPropertyLen();
// 賬號資訊繫結值
char m_account_name[MaxAccountLen];
char m_account_key[MaxAccountLen];
unsigned int m_account_id;
// 各個預處理的繫結引數/繫結結果
void PrepareSelectAccount();
void PrepareInsertAccount();
void PrepareUpdateAccount();
void PrepareDeleteAccount();
// 對應增、刪、改、查四種操作物件
common::db::PrepareOperatorSelect m_select_account;
common::db::PrepareOperatorUpdate m_insert_account;
common::db::PrepareOperatorUpdate m_update_account;
common::db::PrepareOperatorUpdate m_delete_account;
};
#endifPrepareDBService.cpp：
#include "PrepareDBService.h"
PrepareDBService::PrepareDBService()
{
}
PrepareDBService::~PrepareDBService()
{
}
bool PrepareDBService::ProcessStart()
{
//預處理sql
InitPropertyLen();
PrepareSelectAccount();
PrepareInsertAccount();
PrepareUpdateAccount();
PrepareDeleteAccount();
return true;
}
void PrepareDBService::ProcessStop()
{
m_select_account.Release();
m_insert_account.Release();
m_update_account.Release();
m_delete_account.Release();
}
void PrepareDBService::InitPropertyLen()
{
m_property_len[account_name] = sizeof(m_account_name);
m_property_len[account_key] = sizeof(m_account_key);
m_property_len[account_id] = sizeof(m_account_id);
}
void PrepareDBService::PrepareSelectAccount()
{
//預處理sql
m_select_account.BindSql(m_Connect,
"select * from account where account_name = ?;");
m_select_account.BindResult("%s,%s,%u",
m_account_name, &m_property_len[account_name],
m_account_key, &m_property_len[account_key],
&m_account_id);
m_select_account.BindParameter("%s",
m_account_name, &m_property_len[account_name]);
}
bool PrepareDBService::SelectAccount(const char(&name)[MaxAccountLen], char(&key)[MaxAccountLen], unsigned int& id)
{
boost::mutex::scoped_lock lock(m_Lock);
strcpy(m_account_name, name);
if (m_select_account.DoOperator())
{
if (m_select_account.FetchResult())
{
strcpy(key, m_account_key);
id = m_account_id;
m_select_account.FreeResult();
return true;
}
else
{
return false;
}
}
else
{
return false;
}
}
void PrepareDBService::PrepareInsertAccount()
{
m_insert_account.BindSql(m_Connect,
"insert into account(account_name, account_key) values(?, ?);");
m_insert_account.BindParameter("%s,%s",
m_account_name, &m_property_len[account_name],
m_account_key, &m_property_len[account_key]);
}
bool PrepareDBService::InsertAccount(const char(&name)[MaxAccountLen], const char(&key)[MaxAccountLen])
{
boost::mutex::scoped_lock lock(m_Lock);
strcpy(m_account_name, name);
strcpy(m_account_key, key);
return m_insert_account.DoOperator();
}
void PrepareDBService::PrepareUpdateAccount()
{
m_update_account.BindSql(m_Connect,
"update account set account_key = ? where account_name = ?;");
m_update_account.BindParameter("%s,%s",
m_account_key, &m_property_len[account_key],
m_account_name, &m_property_len[account_name]);
}
bool PrepareDBService::UpdateAccount(const char(&name)[MaxAccountLen], const char(&key)[MaxAccountLen])
{
boost::mutex::scoped_lock lock(m_Lock);
strcpy(m_account_name, name);
strcpy(m_account_key, key);
return m_update_account.DoOperator();
}
void PrepareDBService::PrepareDeleteAccount()
{
m_delete_account.BindSql(m_Connect,
"delete from account where account_name = ?;");
m_delete_account.BindParameter("%s",
m_account_name, &m_property_len[account_name]);
}
bool PrepareDBService::DeleteAccount(const char(&name)[MaxAccountLen])
{
boost::mutex::scoped_lock lock(m_Lock);
strcpy(m_account_name, name);
return m_delete_account.DoOperator();
}主函式TestDB.cpp：
#include <iostream>
#include "PrepareDBService.h"
void PrepareAccount()
{
char accountName[PrepareDBService::MaxAccountLen] = { 0 };
char accountKey[PrepareDBService::MaxAccountLen] = { 0 };
unsigned int accountId = 0;
PrepareDBService service;
service.Start("127.0.0.1", 3306, "root", "root", "account");
/////////////////////////Insert/////////////////////////
memset(accountName, 0x00, sizeof(accountName));
strcpy(accountName, "Test001");
memset(accountKey, 0x00, sizeof(accountKey));
strcpy(accountKey, "0000001");
if (service.InsertAccount(accountName, accountKey))
{
std::cout << "InsertAccount name = " << accountName << ", key = " << accountKey << " success" << std::endl;
}
/////////////////////////Update/////////////////////////
memset(accountName, 0x00, sizeof(accountName));
strcpy(accountName, "Test001");
memset(accountKey, 0x00, sizeof(accountKey));
strcpy(accountKey, "1111111");
if (service.UpdateAccount(accountName, accountKey))
{
std::cout << "UpdateAccount name = " << accountName << ", key = " << accountKey << " success" << std::endl;
}
/////////////////////////Select/////////////////////////
memset(accountName, 0x00, sizeof(accountName));
strcpy(accountName, "Test001");
if (service.SelectAccount(accountName, accountKey, accountId))
{
std::cout << "SelectAccount name = " << accountName << ", key = " << accountKey << " , id = " << accountId << std::endl;
}
else
{
std::cout << "no result" << std::endl;
}
/////////////////////////Delete/////////////////////////
memset(accountName, 0x00, sizeof(accountName));
strcpy(accountName, "Test001");
if (service.DeleteAccount(accountName))
{
std::cout << "DeleteAccount name = " << accountName << " success" << std::endl;
}
/////////////////////////Select/////////////////////////
memset(accountName, 0x00, sizeof(accountName));
strcpy(accountName, "Test001");
if (service.SelectAccount(accountName, accountKey, accountId))
{
std::cout << "SelectAccount name = " << accountName << ", key = " << accountKey << " , id = " << accountId << std::endl;
}
else
{
std::cout << "no result" << std::endl;
}
service.Stop();
}
int main(int argc, char* argv[])
{
PrepareAccount();
system("pause");
return 0;
}