对Sqlite数据库C API的简单封装

@H_301_0@1. 头文件

@H_301_0@

#pragma once
#include <string>
#include <sstream>
using namespace std;
#include "<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite/<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite3.h"
#pragma comment(lib,"<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite/<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite3.lib")
class CResultSet
{
public:
	friend class C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr;
public:
	CResultSet();
	~CResultSet();
public:
	int GetColumnNum();
	// 获得结果数目
	int GetRecordCount();
public:
	int GetInt(int row,int column);
	string GetString(int row,int column);
private:
	// <a href="https://www.jb51.cc/tag/huoqu/" target="_blank" class="keywords">获取</a>对应行列的结果
	char * GetAt(int row,int column);
private:
	char **szResult;
	int nRow;
	int nColumn;
};
class C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr
{
public:
	C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr(string filename);
	~C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr();
public:
	int Execute(const char *<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>);
	int Execute(string <a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>);
	CResultSet * ExecuteQuery(string <a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>);
public:
	void FreeResultSet(CResultSet *rs);
public:
	void Begin();
	void Commit();
	void Rollback();
private:
	void print_error(char *error);
private:
	<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite3 *m_conn;
};

@H_301_0@2. 源文件

@H_301_0@

#include "stdafx.h"
#include "<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr.h"
CResultSet::CResultSet()
{
}
CResultSet::~CResultSet()
{
	::<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite3_free_table(szResult);
}
int CResultSet::GetColumnNum()
{
	return nColumn;
}
int CResultSet::GetRecordCount()
{
	return nRow;
}
int CResultSet::GetInt(int row,int column)
{
	return atoi(GetAt(row,column));
}
string CResultSet::GetString(int row,int column)
{
	return string(GetAt(row,column));
}
char * CResultSet::GetAt(int row,int column)
{
	return szResult[(row + 1) * nColumn + column];
}
C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr::C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr(string filename)
{
	int nRet = ::<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite3_open(filename.c_str(),&m_conn);
	if (nRet != <a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ITE_OK)
	{
		print_error("<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite3_open fail");
	}
}
C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr::~C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr()
{
	::<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite3_close(m_conn);
}
int C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr::Execute(const char *<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>)
{
	char *error_msg = NULL;
	int nRet = ::<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite3_exec(m_conn,<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>,(char **) &error_msg);
	if (nRet != <a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ITE_OK)
	{
		print_error(error_msg);
		return -1;
	}
	return nRet;
}
int C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr::Execute(string <a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>)
{
	return Execute(<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>.c_str());
}
CResultSet * C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr::ExecuteQuery(string <a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>)
{
	char *error_msg = NULL;
	CResultSet *pRs = new CResultSet;
	int nRet = ::<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite3_get_table(m_conn,<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>.c_str(),&pRs->szResult,&pRs->nRow,&pRs->nColumn,(char **) &error_msg);	
	if (nRet != <a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ITE_OK)
	{
		print_error(error_msg);
		return NULL;
	}	
	return pRs;
}
void C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr::FreeResultSet(CResultSet *rs)
{
	if (rs != NULL)
	{
		delete rs;
		rs = NULL;
	}	
}
void C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr::Begin()
{
	Execute("BEGIN TRANSACTION");
}
void C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr::Commit()
{
	Execute("COMMIT TRANSACTION");
}
void C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr::Rollback()
{
	Execute("ROLLBACK TRANSACTION");
}
void C<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr::print_error(char *error)
{
	char szError[128];
	memset(szError,128);
	sprintf(szError,"<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite error: %s/n",error);
	OutputDebugStringA(szError);
	<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>ite3_free(error);
}

@H_301_0@3. 测试代码

@H_301_0@

#include <vector>
#include <string>
using namespace std;
#include "<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr.h"
#include "Tools.h"
struct cRecord
{
	int id;
	string name;
	int age;
};
int _tmain(int argc,_TCHAR* argv[])
{
	<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>iteMgr mgr("test.db");
	if (false)
	{
		mgr.Execute("create table test([id] integer primary key autoincrement,[name] text,[age] int);");
		char buf[256];
		memset(buf,256);
		for (int i = 0; i < 100; ++i)
		{
			sprintf(buf,"insert into test(name,age) values(/"tom%d/",%d)",i + 1,i + 20);
			mgr.Execute(buf);
		}
	}
	else
	{
		ResultSet *rs = mgr.ExecuteQuery("select id,name,age from test");
		vector<cRecord> records;
		for (int i = 0; i < rs->GetRecordCount(); ++i)
		{
			cRecord record;
			record.id = rs->GetInt(i,0);
			record.name = CTools::utf8_2_ansi(rs->GetString(i,1).c_str());
			record.age = rs->GetInt(i,2);
			records.push_back(record);
		}
		mgr.FreeResultSet(rs);
	}
	return 0;
}

原文链接：https://www.f2er.com/sqlite/202839.html

对Sqlite数据库C API的简单封装

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