如何通过ADO获得Access数据库中的所有用户表和表信息

本文介绍一种通过ADO列举Access文件中所用用户表和表信息的方法，仅供参考，源代码在VC6.0 ＋XP环境通过测试。

首先，需要引入msado15.dll文件，在stdafx.h中添加：

#import "c:/program files/common files/system/ado/msado15.dll" no_namespace rename("EOF","adoEOF")

其次，将下面的代码复制到cpp文件中：

CString GetType(int nType);
void GetTableInfo(_ConnectionPtr& pConnection, CString strTableName);
BOOL GetDatabaseInfo(CString strFile);

int _tmain(int argc, TCHAR* argv[], TCHAR* envp[])
{
int nRetCode = 0;

//初始化com环境
CoInitialize(NULL);

GetDatabaseInfo("c://test.mdb");

CoUninitialize();
return nRetCode;
}

void GetTableInfo(_ConnectionPtr& pConnection, CString strTableName)
{
_variant_t recAffected;

try
{
int nCount = 0;

//开始打开表，以便得到表的结构
_RecordsetPtr pRecordset;
pRecordset.CreateInstance(__uuidof(Recordset));
pRecordset->Open((LPCTSTR)strTableName, pConnection.GetInterfacePtr()
, adOpenDynamic, adLockOptimistic, adCmdTable);

FieldsPtr fds = pRecordset->GetFields();

//依次读取字段，并显示
//字段名
for(int i = 0; i < fds->GetCount(); i++)
{
FieldPtr fd = fds->GetItem(_variant_t(short(i)));
if(fd->Value.vt != NULL)
{
CString strName((LPCTSTR)fd->GetName());
printf("字段%i,名称%s,类型%s,长度%ld /r/n",i+1
, (LPCTSTR)fd->GetName(), GetType(fd->GetType())
, fd->GetDefinedSize());

}

}

pRecordset->Close();

}
catch(_com_error e)///捕捉异常
{
CString strStatus;
strStatus.Format("错误:%s", (LPCTSTR)e.Description());
}

}

BOOL GetDatabaseInfo(CString strFile)
{

//首先进行数据库连接：

_ConnectionPtr pConnection;
_RecordsetPtr pRecordset;

HRESULT hr;
try
{
hr = pConnection.CreateInstance("ADODB.Connection");//创建Connection对象
if(SUCCEEDED(hr))
{
CString str;
str.Format(_T("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=%s"), strFile);//需要设置文件的路径名

hr = pConnection->Open(_bstr_t(str.GetBuffer(1)), "", "", adModeUnknown);///连接数据库
///上面一句中连接字串中的Provider是针对ACCESS2000环境的，
//对于ACCESS97,需要改为:Provider=Microsoft.Jet.OLEDB.3.51
if(!SUCCEEDED(hr))
{
printf("连接数据库失败");
return FALSE;
}
}
}
catch(_com_error e)///捕捉异常
{
CString errormessage;
errormessage.Format("连接数据库失败!/r/n%s", (LPCTSTR)e.Description());
printf(errormessage);///显示错误信息

return FALSE;
}

pRecordset.CreateInstance(__uuidof(Recordset));

//开始查询所有表名称
pRecordset = pConnection->OpenSchema(adSchemaTables);//枚举表的名称处理
while(!(pRecordset->adoEOF))
{
CString strTableType;
CString strTableName;
_bstr_t table_name = pRecordset->Fields->GetItem("TABLE_NAME")->Value;//获取表的名称

_bstr_t table_type = pRecordset->Fields->GetItem("TABLE_TYPE")->Value;//获取表的类型

strTableType.Format("%s",(LPCSTR) table_type);
strTableName.Format("%s",(LPCSTR) table_name);

if(!lstrcmp(strTableType,_T("TABLE")))
{
//strTableName是表名称
printf("查到一个表：%s/r/n", strTableName);

GetTableInfo(pConnection, strTableName);
}

pRecordset->MoveNext();
}
pRecordset->Close();
pConnection->Close();

return TRUE;

}

CString GetType(int nType)
{
switch(nType)
{
case adEmpty:
{
return _T("Empty");
}
case adSmallInt:
{
return _T("SmallInt");
}
case adInteger:
{
return _T("Integer");
}
case adSingle:
{
return _T("Single");
}
case adDouble:
{
return _T("Double");
}
case adCurrency:
{
return _T("Currency");
}
case adTinyInt:
{
return _T("TinyInt");
}
case adBigInt:
{
return _T("BigInt");
}
case adUnsignedTinyInt:
{
return _T("UnsignedTinyInt");
}
case adUnsignedSmallInt:
{
return _T("UnsignedSmallInt");
}
case adUnsignedInt:
{
return _T("UnsignedInt");
}
case adUnsignedBigInt:
{
return _T("UnsignedBigInt");
}
case adDecimal:
{
return _T("Decimal");
}
case adNumeric:
{
return _T("Numeric");
}
case adBoolean:
{
return _T("Boolean");
}
case adError:
{
return _T("Error");
}
case adUserDefined:
{
return _T("UserDefined");
}
case adVariant:
{
return _T("Variant");
}
case adIDispatch:
{
return _T("IDispatch");
}
case adIUnknown:
{
return _T("IUnknown");
}
case adGUID:
{
return _T("GUID");
}
case adDate:
{
return _T("Date");
}
case adDBDate:
{
return _T("DBDate");
}
case adDBTime:
{
return _T("DBTime");
}
case adDBTimeStamp:
{
return _T("DBTimeStamp");
}
case adBSTR:
{
return _T("BSTR");
}
case adChar:
{
return _T("Char");
}
case adVarChar:
{
return _T("VarChar");
}
case adLongVarChar:
{
return _T("LongVarChar");
}
case adWChar:
{
return _T("WChar");
}
case adVarWChar:
{
return _T("VarWChar");
}
case adLongVarWChar:
{
return _T("LongVarWChar");
}
case adBinary:
{
return _T("Binary");
}
case adVarBinary:
{
return _T("VarBinary");
}
case adLongVarBinary:
{
return _T("LongVarBinary");
}
case adChapter:
{
return _T("Chapter");
}
case adFileTime:
{
return _T("FileTime");
}
case adPropVariant:
{
return _T("PropVariant");
}
case adVarNumeric:
{
return _T("VarNumeric");
}
case adArray:
{
return _T("Array");
}
default:
{
return _T("");
}
}

编译运行，可以打印Access数据库的信息，一个例子如下：

查到一个表：Result
字段1,名称ResultID,类型Integer,长度4
字段2,名称TaskID,类型Integer,长度4
字段3,名称TestTime,类型Integer,长度4
字段4,名称DestIP,类型VarWChar,长度255
字段5,名称TestType,类型Integer,长度4
字段6,名称AvgDelay,类型Integer,长度4
字段7,名称MinDelay,类型Integer,长度4
字段8,名称MaxDelay,类型Integer,长度4
字段9,名称IPAvailability,类型Integer,长度4
字段10,名称IPDV,类型Double,长度8
字段11,名称LossRate,类型Double,长度8
查到一个表：ResultData
字段1,名称ResultDataID,类型Integer,长度4
字段2,名称ResultID,类型Integer,长度4
字段3,名称ElapsedTime,类型Integer,长度4
字段4,名称PacketSize,类型Integer,长度4
字段5,名称ResultType,类型Integer,长度4
字段6,名称Delay,类型Integer,长度4
字段7,名称ErrorInfo,类型VarWChar,长度255
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