VC+ADO动态创建Access数据库
ado技术目前已经成为连接数据库的主流技术,下面介绍如何使用ado来动态创建access数据库。 为了使用ado,必须引入微软的两个动态连接库msadox.dll和msado15.dll: #pragma warning (disable: 4146) 将上述代码加入到stdafx.h文件中,由于ado是com组件,因此使用ado之前还要初始化com环境: CoInitialize(NULL); 下面是一个在access数据库中创建表的sql语句的例子: create table test scoredecimal(12,4) not null default 0, ID smallint not null default 0, birthday date, sex char(1), CONSTRAINT CK_CH_SEX Check(SEX in ('N','V')), CONSTRAINT PK_ID Primary Key (ID) ); 使用ADOX::CatalogPtr来创建mdb文件: HRESULT hr = S_OK; //Set ActiveConnection of Catalog to this string try if(FAILED(hr)) {_com_issue_error(hr); }else {m_pCatalog->Create(_bstr_t(strcnn)); //Create MDB } 创建一个连接对象打开刚刚建立的mdb文件: _ConnectionPtr g_pConn; g_pConn.CreateInstance(__uuidof(Connection)); g_pConn->Open("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=d:\\test.mdb;", 下面函数用来执行sql文件中的sql语句: // Function name : RunSqlScript UINT nBytesRead = fSql.Read(buffer,nFileLength); //把sql文件内容读入内存缓冲区 p = pSQL = buffer; m_nRecordsAffected = 0; try 调用RunSqlScript创建access数据库中的表: RunSqlScript(_T("d:\\test.sql")); 关闭数据库连接: g_pConn->Close(); ::CoUninitialize(); 以上代码演示了怎样在vc中利用ado根据sql文件动态创建一个access数据库。
#import "c:\Program Files\Common Files\system\ado\msadox.dll"
#import "c:\Program Files\Common Files\system\ado\msado15.dll" no_namespace rename("EOF", "EndOfFile")
#pragma warning (default: 4146)
(
nametext(20) WITH COMPRESSION not null,
CString strcnn(_T("Provider=Microsoft.JET.OLEDB.4.0;Data source = d:\\test.mdb"));
{ ADOX::_CatalogPtr m_pCatalog = NULL;
hr = m_pCatalog.CreateInstance(__uuidof (ADOX::Catalog));
}
catch(_com_error &e)
{
// Notify the user of errors if any.
AfxMessageBox(_T(“error“));
}
"", "", adConnectUnspecified);
// Description: 执行SQL脚本, peckermen@163.com, 2003-09-15
// Return type: BOOL 成功返回TRUE
// Argument : LPCSTR SqlScriptFile SQL脚本文件名
// Argument : char separator SQL 分割符号, 缺省';'
// Argument : char RemarkSQL 注释符号, 缺省'-'
BOOL RunSqlScript(LPCSTR SqlScriptFile, char separator = ';', char Remark = '-')
{
BOOL bRet = FALSE;
CFileFind finder;
CString ErrLong;
if (finder.FindFile(SqlScriptFile) == TRUE)
{
CFile fSql;
TCHAR *buffer, *pSQL, *p;
fSql.Open(SqlScriptFile,Cfile&::modeRead);
UINT nFileLength = fSql.GetLength();
buffer = (TCHAR *)malloc((nFileLength + 1) * sizeof(TCHAR));
_tcsnset(buffer, TCHAR('\0'), nFileLength + 1);
fSql.Close();
BOOL bRunOK = FALSE;
BOOL bInNote = FALSE;
BOOL bSkip = FALSE;
CString strSQL;
TCHAR ch;
ErrLog = _T("");
while (p < (buffer + nFileLength)){
//判断是否是注释行
if (bInNote)
{
if (*p == TCHAR('\x0a'))
bInNote = FALSE;
}
else
{
if ((*p == Remark) && (*(p+1) == Remark))
{
bInNote = TRUE;
p++;
}
else
{
//判断是否是sql语句结束标志
if (*p == separator){
strSQL = _T("");
bSkip = FALSE;
while (pSQL < p)
{
if (bSkip == FALSE){
if ((*(pSQL) == Remark) &&(*(pSQL+1) == Remark))
{
bSkip = TRUE;
pSQL++;
}
else
{
ch = *pSQL;
strSQL = strSQL+ch;
}
}
else{
if (*pSQL = TCHAR('\x0a')){
bSkip = FALSE;
ch = TCHAR(' ');
strSQL = strSQL + ch;
}
}
pSQL++;
}
pSQL = p + 1;
ErrLog = ErrLog + _T("-- SQL Running ...\n");
ErrLog = ErrLog + strSQL;
_variant_t vRecords;
{
g_pConn->CursorLocation = adUseClient;
g_pConn->Execute(_bstr_t((LPCTSTR)strSQL), &vRecords, adExecuteNoRecords);
m_nRecordsAffected = vRecords.iVal;
bRunOK = TRUE;
}
catch(_com_error &e)
{
bRunOK = FALSE;
}
if (bRunOK)
ErrLog = ErrLog + _T("\n-- Successed!\n");
else
{
ErrLog = ErrLog + _T("\n-- Failed!\n");
break;
}
}
}
}
p++;
}
free(buffer);
bRet = bRunOK;
}
return bRet;
}