本文共 3789 字，大约阅读时间需要 12 分钟。
| ado技术目前已经成为连接数据库的主流技术，下面我来介绍如何使用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)#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)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(nametext(20) WITH COMPRESSION not null,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 stringCString strcnn(_T("Provider=Microsoft.JET.OLEDB.4.0;Data source = d://test.mdb"));try{ ADOX::_CatalogPtr m_pCatalog = NULL;hr = m_pCatalog.CreateInstance(__uuidof (ADOX::Catalog));if(FAILED(hr)) { _com_issue_error(hr); } else { m_pCatalog->Create(_bstr_t(strcnn)); //Create MDB }}catch(_com_error &e){ // Notify the user of errors if any. AfxMessageBox(_T(“error“));}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;", "", "", adConnectUnspecified); 下面函数用来执行sql文件中的sql语句：// Function name : RunSqlScript// 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);UINT nBytesRead = fSql.Read(buffer,nFileLength); //把sql文件内容读入内存缓冲区fSql.Close();p = pSQL = buffer;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;m_nRecordsAffected = 0;try{ 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;}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，欢迎指正。 |
转载地址：http://soxqj.baihongyu.com/