zoukankan      html  css  js  c++  java

  • vc ado 操作数据库类 from http://www.codeproject.com/database/caaadoclass1.asp

    Overview

    Overview

    I created these classes to make it easy to work with ADO. For this I created the CADODatabse class and the CADORecordset class.

    The CADODatabase Class

    The CADODatabase class has a set of functions that corresponds to the _ConnectionPtr.

    CADODatabase::CADODatabase

    Creates a CADODatabase object.

    CADODatabase();

    CADODatabase::Open

    The Open function opens a connection to a database.

    BOOL Open(LPCTSTR lpstrConnection = _T(""));
throw(CADOException);

    Parameters

    LPCTSTR lpstrConnection - The connection string.

    See Sample

    Note: the class has the function SetConnectionString. You can insert the connection string through this function. In this case you can do the following:

    Collapse
    //Sample with Connection string for SQL Server

CADODatabase* pAdoDb = new CADODatabase();
CString strConnection = _T("");

strConnection = _T("Provider=MSDASQL;PersistSecurityInfo=False;"
                   "Trusted_Connection=Yes;"
                   "Data Source=Access Sql Server;catalog=sampledb");
pAdoDb->SetConnectionString(strConnection);

if(pAdoDb->Open())
  DoSomething();
.
.
.

//Sample with Connection String for Access database

CADODatabase* pAdoDb = new CADODatabase();
CString strConnection = _T("");

strConnection = _T("Provider=Microsoft.Jet.OLEDB.4.0;"
              "Data Source=C://VCProjects//ADO//Test//dbTest.mdb");
pAdoDb->SetConnectionString(strConnection);

if(pAdoDb->Open())
{
  DoSomething();
  .
  .
  .
  pAdoDb->Close();
}

delete pAdoDb;

    CADODatabase::Execute

    The Execute function executes a SQL statement in the open database.

    BOOL Execute(LPCTSTR lpstrExec);
throw(CADOException);

    Parameters

    LPCTSTR lpstrExec - A string pointer containing the SQL statement to execute.

    CADODatabase* pAdoDb = new CADODatabase();
CString strConnection = _T("");

strConnection = _T("Provider=MSDASQL;"
                   "PersistSecurityInfo=False;"
                   "Trusted_Connection=Yes"
                "Data Source=Access Sql Server;catalog=sampledb");

if(pAdoDb->Open(strConnection))
 pAdoDb->Execute("Delete From tblClients Where Cheker = 3");

    Return Value

    The function returns TRUE if it was executed successfully.

    CADODatabase::GetRecordsAffected

    The GetRecordsAffcted function returns the number of records affected by the last SQL statement executed.

    int GetRecordsAffected();

    CADODatabase::GetActiveConnection

    The GetActiveConnection returns the active connection.

    _ConnectionPtr GetActiveConnection();

    CADODatabase::GetRecordCount

    GetRecordCount returns the number of records affected in a query.

    DWORD GetRecordCount(_RecordsetPtr m_pRs);

    Parameters

    _RecorsetPtr m_Prs - The recordset.

    CADODatabase::BeginTransaction

    Call this function to initiate a transaction. After you call BeginTransaction, updates you make to your data take effect when you commit the transaction.

    long BeginTransaction();

    CADODatabase::CommitTransaction

    Call CommitTransaction function to commit a transaction, for example, save a group of edits and updates to one or more databases.

    long CommitTransaction();

    CADODatabase::RollbackTransaction

    Call RollbackTransaction function to end the current transaction and restore all databases to their condition before the transaction was begun.

    long RollbackTransaction();

    CADODatabase::IsOpen

    The IsOpen function returns the status of the connection with the database.

    BOOLIsOpen();

    Return Value

    The function returns TRUE if the connection to the database is open.

    CADODatabase::Close

    The Close function closes the connection to the database.

    void Close();

    CADODatabase::SetConnectionString

    With the SetConnectionString, you can insert the connection string.

    void SetConnectionString(LPCTSTR lpstrConnection);

    Parameters

    LPCTSTR lpstrConnection - A connection string used for opening the database.

    See CADODatabase::Open();

    CADODatabase::GetConnectionString

    The GetConnectionString function returns the connection string used for making a connection with a database.

    CString GetConnectionString();

    CADODatabase::SetConnectionMode

    The SetConnectionMode function sets the mode of connection.

    void SetConnectionMode(cadoConnectModeEnum nMode);

    Parameters

    cadoConnectModeEnum nMode - a variable that defines the connection mode to be used. It can be one of the following:

    • CADODatabase::connectModeUnknown
    • CADODatabase::connectModeRead
    • CADODatabase::connectModeWrite
    • CADODatabase::connectModeReadWrite
    • CADODatabase::connectModeShareDenyRead
    • CADODatabase::connectModeShareDenyWrite
    • CADODatabase::connectModeShareExclusive
    • CADODatabase::connectModeShareDenyNone

    CADODatabase::GetLastError

    The GetLastError function returns the last error code.

    DWORD GetLastError();

    CADODatabase::GetLastErrorString

    The GetLastErrorString function returns the last error string.

    CString GetLastErrorString();

    The CADORecordset Class

    The CADORecordset class has a set of functions that corresponds to the _RecordsetPtr.

    CADORecordset::CADORecordset

    Creates a CADORecordset object.

    CADODatabase();
CADORecordset(CADODatabase* pAdoDatabase);

    Parameters

    CADODatabase* pAdoDatabase - A CADODatabase object pointer.

    CADORecordset::Open

    The Open function opens a recordset.

    BOOL Open(_ConnectionPtr mpdb, LPCTSTR lpstrExec = _T(""), 
                     int nOption = CADORecordset::openUnknown);
BOOL Open(LPCTSTR lpstrExec = _T(""), 
                     int nOption = CADORecordset::openUnknown);

    Parameters

    • _ConnectionPtr mpdb - A connection pointer.
    • LPCTSTR lpstrExec - A string pointer containing an SQL SELECT statement.
    • int nOption - An integer that defines the access mode. The values are as follows:
      • CADORecordset::openUnknown
      • CADORecordset::openQuery
      • CADORecordset::openTable
      • CADORecordset::openStoredProc

    Return Value

    Returns TRUE if it was executed successfully.

    See Sample

    CADORecordset::Execute

    The Execute function opens a recordset.

    BOOL Execute(CADOCommand* pCommand);
throw(CADOException);

    Parameters

    CADOCommand* pCommand - A CADOCommand pointer.

    Return Value

    Returns TRUE if it was executed successfully.

    See Sample

    CADORecordset::GetQuery;

    GetQuery returns the string containing the SQL SELECT statement.

    CString GetQuery();

    CADORecordset::SetQuery

    void SetQuery(LPCSTR strQuery);

    Parameters

    LPCTSTR strQuery - A string pointer containing an SQL SELECT statement.

    CADORecordset::RecordBinding

    BOOL RecordBinding(CADORecordBinding pAdoRecordBinding);

    Parameters

    CADORecordBinding pAdoRecordBinding

    CADORecordset::GetRecordCount

    GetRecordCount returns the number of records accessed in the recordset.

    DWORD GetRecordCount();

    See Sample

    CADORecordset::IsOpen

    IsOpen determines if the recordset is open.

    BOOL IsOpen();

    Return Value

    This member function returns TRUE if the recordset has not been closed.

    CADORecordset::Close

    The Close function closes the recordset.

    void Close();

    See Sample

    CADORecordset::GetFieldCount

    The GetFieldCount function returns the number of fields in the recordset.

    long GetFieldCount();

    CADORecordset::GetFieldValue

    The GetFieldValue function returns a value that contains the value of a field.

    Collapse
    BOOL GetFieldValue(LPCTSTR lpFieldName, int nValue);
BOOL GetFieldValue(int nIndex, int nValue);
BOOL GetFieldValue(LPCTSTR lpFieldName, long lValue);
BOOL GetFieldValue(int nIndex, long lValue);
BOOL GetFieldValue(LPCTSTR lpFieldName, unsigned long ulValue);
BOOL GetFieldValue(int nIndex, unsigned long ulValue);
BOOL GetFieldValue(LPCTSTR lpFieldName, double dbValue);
BOOL GetFieldValue(int nIndex, double dbValue);
BOOL GetFieldValue(LPCTSTR lpFieldName, CString strValue, 
                         CString strDateFormat = _T(""));
BOOL GetFieldValue(int nIndex, CString strValue, 
                         CString strDateFormat = _T(""));
BOOL GetFieldValue(LPCTSTR lpFieldName, COleDateTime time);
BOOL GetFieldValue(int nIndex, COleDateTime time);
BOOL GetFieldValue(LPCTSTR lpFieldName, bool bValue);
BOOL GetFieldValue(int nIndex, bool bValue);
BOOL GetFieldValue(LPCTSTR lpFieldName, COleCurrency cyValue);
BOOL GetFieldValue(int nIndex, COleCurrency cyValue);
throw(CADOException);

    Parameters

    • LPCTSTR lpFieldName - A pointer to a string that contains the name of a field.
    • int nIndex - A zero-based index of the field in the recordset’s Fields collection, for lookup by index.
    • double dbValue - A reference to an object that will store the value of a field.
    • long lValue - A reference to an object that will store the value of a field.
    • unsigned long ulValue - A reference to an object that will store the value of a field.
    • int nValue - A reference to an object that will store the value of a field.
    • CString strValue - A reference to an object that will store the value of a field.
    • CString strDateFormat - A formatting time string similar to the strftime formatting string. The more common are:
      • %a - Abbreviated weekday name
      • %A - Full weekday name
      • %b - Abbreviated month name
      • %B - Full month name
      • %c - Date and time representation appropriate for locale
      • %d - Day of month as decimal number (01 - 31)
      • %H - Hour in 24-hour format (00 - 23)
      • %I - Hour in 12-hour format (01 - 12)
      • %j - Day of year as decimal number (001 - 366)
      • %m - Month as decimal number (01 - 12)
      • %M - Minute as decimal number (00 - 59)
      • %p - Current locale’s A.M./P.M. indicator for 12-hour clock
      • %S - Second as decimal number (00 - 59)
      • %U - Week of year as decimal number, with Sunday as first day of week (00 - 53)
      • %w - Weekday as decimal number (0 - 6; Sunday is 0)
      • %W - Week of year as decimal number, with Monday as first day of week (00 - 53)
      • %x - Date representation for current locale
      • %X - Time representation for current locale
      • %y - Year without century, as decimal number (00 - 99)
      • %Y - Year with century, as decimal number
    • COleDateTime time - A reference to an object that will store the value of a field.
    • bool bValue - A reference to an object that will store the value of a field.
    • COleCurrency cyValue - A reference to an object that will store the value of a field.

    See Sample

    CADORecordset::IsFieldNull

    The IsFieldNull function determines if the field data is null.

    BOOL IsFieldNull(LPCTSTR lpFieldName);
BOOL IsFieldNull(int nIndex);
throw(CADOException);

    Parameters

    • LPCTSTR lpFieldName - A pointer to a string that contains the name of a field.
    • int nIndex - A zero-based index of the field in the recordset’s Fields collection, for lookup by index.

    Return Value

    This function returns TRUE if the field data is null.

    CADORecordset::IsFieldEmpty

    The IsFieldEmpty function determines if the field data is empty.

    BOOL IsFieldEmpty(LPCTSTR lpFieldName);
BOOL IsFieldEmpty(int nIndex);
throw(CADOException);

    Parameters

    • LPCTSTR lpFieldName - A pointer to a string that contains the name of a field.
    • int nIndex - A zero-based index of the field in the recordset’s Fields collection, for lookup by index.

    Return Value

    This function returns TRUE if the field data is empty.

    CADORecordset::IsEof

    BOOL IsEof();

    Return Value

    This function returns TRUE if the current position contains no records.

    See Sample

    CADORecordset::IsBof

    BOOL IsBof();

    Return Value

    This function returns TRUE if the current position is the bottom of the recordset.

    CADORecordset::MoveFirst
    CADORecordset::MoveNext
    CADORecordset::MovePrevious
    CADORecordset::MoveLast

    These functions make the first/next/previous/or last record of the recordset as the current record.

    void MoveFirst();
void MoveNext();
void MovePrevious();
void MoveLast();

    See Sample

    CADORecordset::GetAbsolutePage
    CADORecordset::SetAbsolutePage

    Indicates on which page the current record resides.

    long GetAbsolutePage();
void SetAbsolutePage(int nPage);

    Parameters

    int nPage - The number of the page starting from 1.

    See Sample

    CADORecordset::GetPageCount

    GetPageCount returns the number of pages in the recordset.

    long GetPageCount();

    See Sample

    CADORecordset::GetPageSize
    CADORecordset::SetPageSize

    Indicates the number of records per page.

    long GetPageSize();
void SetPageSize(int nSize);

    Parameters

    int nSize - set the number of records per page.

    For example

    CADORecordset* pRs = new CADORecordset(pDb);

if(pRs->Open("MyBigTable", CADORecordset::openTable))
{
    pRs->SetPageSize(5);
    for(register int nPageIndex = 1; nPageIndex <= pRs->GetPageCount(); 
        nPageIndex++)
    {
        pRs->SetAbsolutePage(nPageIndex);
        for(register int nRecNumber = 0; nRecNumber < pRs->GetPageSize(); 
            nRecNumber++)
        {
            long lVal;
            pRs->GetFieldValue("ID", lVal);
            pRs->MoveNext();

            if(pRs->IsEof())
                break;
        }
    }
    pRs->Close();
}

delete pRs;

    CADORecordset::GetAbsolutePosition
    CADORecordset::SetAbsolutePosition

    Indicates the position of the record in the recordset.

    long GetAbsolutePosition();
void SetAbsolutePosition(int nPosition);

    Parameters

    int nPosition - Move to the position in the recordset.

    GetAbsolutePosition() can return the position of the record or one of the following values:

    • CADORecordset::positionUnknown
    • CADORecordset::positionBOF
    • CADORecordset::positionEOF

    CADORecordset::GetFieldInfo

    GetFieldInfo returns the attributes of a field.

    BOOL GetFieldInfo(LPCTSTR lpFieldName, CAdoFieldInfo* fldInfo);
BOOL GetFieldInfo(int nIndex, CAdoFieldInfo* fldInfo);

    Parameters

    • LPCTSTR lpFieldName - A pointer to a string that contains the name of a field.
    • int nIndex - A zero-based index of the field in the recordset's Fields collection, for lookup by index.
    • CAdoFieldInfo* fldInfo - A struct that returns the field attributes. 
    struct CADOFieldInfo
{
    char m_strName[30];
    short m_nType;
    long m_lSize;
    long m_lDefinedSize;
    long m_lAttributes;
    short m_nOrdinalPosition;
    BOOL m_bRequired;
    BOOL m_bAllowZeroLength;
    long m_lCollatingOrder;
};

    The element m_nType of the class CADOFieldInfo can be one of the following values:

    • CADORecordset::typeEmpty
    • CADORecordset::typeTinyInt
    • CADORecordset::typeSmallInt
    • CADORecordset::typeInteger
    • CADORecordset::typeBigInt
    • CADORecordset::typeUnsignedTinyInt
    • CADORecordset::typeUnsignedSmallInt
    • CADORecordset::typeUnsignedInt
    • CADORecordset::typeUnsignedBigInt
    • CADORecordset::typeSingle
    • CADORecordset::typeDouble
    • CADORecordset::typeCurrency
    • CADORecordset::typeDecimal
    • CADORecordset::typeNumeric
    • CADORecordset::typeBoolean
    • CADORecordset::typeError
    • CADORecordset::typeUserDefined
    • CADORecordset::typeVariant
    • CADORecordset::typeIDispatch
    • CADORecordset::typeIUnknown
    • CADORecordset::typeGUID
    • CADORecordset::typeDate
    • CADORecordset::typeDBDate
    • CADORecordset::typeDBTime
    • CADORecordset::typeDBTimeStamp
    • CADORecordset::typeBSTR
    • CADORecordset::typeChar
    • CADORecordset::typeVarChar
    • CADORecordset::typeLongVarChar
    • CADORecordset::typeWChar
    • CADORecordset::typeVarWChar
    • CADORecordset::typeLongVarWChar
    • CADORecordset::typeBinary
    • CADORecordset::typeVarBinary
    • CADORecordset::typeLongVarBinary
    • CADORecordset::typeChapter
    • CADORecordset::typeFileTime
    • CADORecordset::typePropVariant
    • CADORecordset::typeVarNumeric
    • CADORecordset::typeArray

    For example

    if(prs->Open("Clients", CADORecordset::openTable))
{
    CADOFieldInfo pInfo;

    prs->GetFieldInfo("Description", &pInfo);

    if(pInfo.m_nType == CADORecordset::typeVarChar)
        AfxMessageBox("The type Description Field Is VarChar");
}


if(prs->Open("TestTable", CADORecordset::openTable))
{
    CADOFieldInfo* fInfo = new CADOFieldInfo;

    prs.GetFieldInfo(0, fInfo);
    CString strFieldName = fInfo->m_strName;
    prs->Close();
}

    Return Value

    Returns TRUE if it was executed successfully.

    CADORecordset::GetChunk

    This function returns all, or a portion, of the contents of a large text or binary data Field object.

    BOOL GetChunk(LPCTSTR lpFieldName, CString& strValue);
BOOL GetChunk(int nIndex, CString& strValue);
BOOL GetChunk(LPCTSTR lpFieldName, LPVOID pData);
BOOL GetChunk(int nIndex, LPVOID pData);

    Parameters

    • LPCTSTR lpFieldName - A pointer to a string that contains the name of a field.
    • int nIndex - A zero-based index of the field in the recordset's Fields collection, for lookup by index.
    • CString& strValue - A string pointer that contains the data that returns from the object.
    • LPVOID pData - A pointer that contains the data that returns from the object.

    Return Value

    Returns TRUE if it was executd successfully.

    See Sample

    CADORecordset::AppendChunk

    This function appends data to a large text or binary data field.

    BOOL AppendChunk(LPCTSTR lpFieldName, LPVOID lpData, UINT nBytes);
BOOL AppendChunk(int nIndex, LPVOID lpData, UINT nBytes);
throw(CADOException);

    Parameters

    • LPCTSTR lpFieldName - A pointer to a string that contains the name of a field.
    • int nIndex - A zero-based index of the field in the recordset's Fields collection, for lookup by index.
    • LPVOID lpData - A pointer that contains the data to append to the object.
    • UINT nBytes - A UINT that indicates the size of the data to be inserted.

    Return Value

    Returns TRUE if it was executed successfully.

    For example

    //Sample of AppendChunck
prs.AddNew();
prs.SetFieldValue("ID", 5);
prs.SetFieldValue("Description", "Client 05");
prs.SetFieldValue("Checker", 1);
prs.AppendChunk("Document", 
    "This Document is the story of Bob and his Friends...", 37);
prs.Update();

//Sample of GetChunck
char data[1024];
prs.GetChunk("Document", (LPVOID)&data);

    CADORecordset::GetString

    This function returns a recordset as a string.

    CString GetString(LPCTSTR lpCols, LPCTSTR lpRows, LPCTSTR lpNull, 
                  long numRows = 0);

    Parameters

    • LPCTSTR lpCols - A columns delimiter.
    • LPCTSTR lpRows - A rows delimiter.
    • LPCTSTR lpNull - An expression that represents a null value.
    • long numRows - The number of rows affected.

    CADORecordset::GetLastError

    The GetLastError function returns the last error code.

    DWORD GetLastError();

    CADORecordset::GetLastErrorString

    The GetLastErrorString function returns the last error string.

    CString GetLastErrorString();

    CADORecordset::AddNew

    The AddNew function adds a record in the open recordset.

    BOOL AddNew();
throw(CADOException);

    Return Value

    Returns TRUE if it was executed successfully.

    See Sample

    CADORecordset::Edit

    The Edit function allows changes to the current record in the open recordset.

    void Edit();

    CADORecordset::Delete

    The Delete function deletes the current record in the open recordset.

    BOOL Delete();

    Return Value

    Returns TRUE if it was executed successfully.

    CADORecordset::Update

    The Update function updates the pending updates in the current record.

    BOOL Update();
throw(CADOException);

    Return Value

    Returns TRUE if it was executed successfully.

    See Sample

    CADORecordset::CancelUpdate

    The CancelUpdate function cancels any pending update in the open recordset.

    void CancelUpdate();

    CADORecordset::SetFieldValue

    The SetFieldValue function sets the value of a field.

    Collapse
    BOOL SetFieldValue(int nIndex, int nValue);
BOOL SetFieldValue(LPCTSTR lpFieldName, int nValue);
BOOL SetFieldValue(int nIndex, long lValue);
BOOL SetFieldValue(LPCTSTR lpFieldName, long lValue);
BOOL SetFieldValue(int nIndex, unsigned long ulValue);
BOOL SetFieldValue(LPCTSTR lpFieldName, unsigned long ulValue);
BOOL SetFieldValue(int nIndex, double dblValue);
BOOL SetFieldValue(LPCTSTR lpFieldName, double dblValue);
BOOL SetFieldValue(int nIndex, CString strValue);
BOOL SetFieldValue(LPCTSTR lpFieldName, CString strValue);
BOOL SetFieldValue(int nIndex, COleDateTime time);
BOOL SetFieldValue(LPCTSTR lpFieldName, COleDateTime time);
BOOL SetFieldValue(int nIndex, bool bValue);
BOOL SetFieldValue(LPCTSTR lpFieldName, bool bValue);
BOOL SetFieldValue(int nIndex, COleCurrency cyValue);
BOOL SetFieldValue(LPCTSTR lpFieldName, COleCurrency cyValue);

    Parameters

    • LPCTSTR lpFieldName - A pointer to a string that contains the name of a field.
    • int nIndex - A zero-based index of the field in the recordset’s Fields collection, for lookup by index.
    • int nValue - A pointer to an object containing the value of the field.
    • long lValue - A pointer to an object containing the value of the field.
    • unsigned long lValue - A pointer to an object containing the value of the field.
    • double dbValue - A pointer to an object containing the value of the field.
    • CString strValue - A pointer to an object containing the value of the field.
    • COleDateTime time - A pointer to an object containing the value of the field.
    • bool bValue - A pointer to an object containing the value of the field.
    • COleCurrency cyValue - A pointer to an object containing the value of the field.

    Return Value

    Returns TRUE if it was executed successfully.

    See Sample

    For example

    CADORecordset* prs = new CADORecordset(m_pAdoDb);
prs->Open("Test", openTable);

prs->AddNew();
prs->SetFieldValue(0, "dataU");
prs->SetFieldValue(1, "data01");
prs->SetFieldValue(2, (long)51000);
COleDateTime time = COleDateTime(2001,6,15, 10, 8, 30);
prs->SetFieldValue(3, time);
prs->Update();
prs->Close();

delete prs;

    CADORecordset::Find

    The Find function locates a string from the current position in the open recordset using an operator of comparison.

    BOOL Find(LPCTSTR lpFind, 
          int nSearchDirection = CADORecordset::searchForward);

    Parameters

    • LPCTSTR lpFind - A string expression used to locate the record.
    • int nSearchDirection - A value that indicates the type of operation. The possible values are:
      • CADORecordset::searchForward - Find the next location.
      • CADORecordset::searchBackward - Find the previous location.

    Return Value

    Returns TRUE if it was executed successfully.

    For example

    if(prs.Find("Field0 LIKE 'dataU%'"))
{
  prs.Delete();
  while(prs.FindNext())
    prs.Delete();
}

    CADORecordset::FindFirst

    The FindFirst function locates a string from the beginning in the open recordset using an operator of comparison.

    BOOL FindFirst(LPCTSTR lpFind);

    Parameters

    LPCTSTR lpFind - A string expression used to locate the record.

    Return Value

    Returns TRUE if it was executed successfully.

    CADORecordset::FindNext

    The FindNext function locates a string from the last position in the open recordset using the operator of comparison used in FindFirst or Find functions.

    BOOL FindNext();

    Return Value

    Returns TRUE if it was executed successfully.

    See Sample

    CADORecordset::GetBookmark

    The GetBookmark function saves the position of the current record.

    BOOL GetBookmark();

    Return Value

    Returns TRUE if it was executed successfully.

    CADORecordset::SetBookmark

    The SetBookmark function returns to the position saved at any time.

    void SetBookmark();

    Return Value

    Returns TRUE if it was executed successfully.

    CADORecordset::SetFilter

    The SetFilter indicates a filter for data in an open Recordset.

    BOOL SetFilter(LPCTSTR strFilter);
throw(CADOException);

    Parameters

    LPCTSTR strFilter - a string composed by one or more individual clauses concatenated with AND or OR operators.

    Return Value

    Returns TRUE if it was executed successfully.

    For example

    CADORecordset* pRs = new CADORecordset(pDb);

if(pRs->Open("tblTest", CADORecordset::openTable))
{
    CString strFilter = _T("LastName = 'Smith' And Age > 30");
    pRs->SetFilter(strFilter);
    .
    .
    pRs->Close();
}

delete pRs

    CADORecordset::SetSort

    The SetSort function sets the sort order for records in a CADORecordset object.

    BOOL SetSort(LPCTSTR lpstrCriteria);
throw(CADOException);

    Parameters

    LPCTSTR lpstrCriteria - A string that contains the ORDER BY clause of an SQL statement.

    Return Value

    Returns TRUE if it was executed successfully.

    CADORecordset::GetRecordset

    The GetRecordset function returns a pointer to an open recordset.

    _RecordsetPtr GetRecordset();

    CADORecordset::GetActiveConnection

    The GetActiveConnection returns the active connection.

    _ConnectionPtr GetActiveConnection();

    CADORecordset::Clone

    The Clone function creates a duplicate CADORecordset object from an existing CADORecordset object.

    BOOL Clone(CADORecordset pAdoRecordset);
throw(CADOException);

    Parameters

    CADORecordset pAdoRecordset is an existing CADORecordset object.

    Return Value

    Returns TRUE if it was executed successfully.

    For example

    CADORecordset m_pRs; //Original Recordset
CADORecordset RS;   //Duplicate Recordset
CADORecordset* pRs = CADORecordset(m_pDb);

if(pRs->Open("tblTest", CADORecordset::openTable)) //Open the Original 
Recordset
{
    pRs->Clone(RS); //Create the clone of the original Recordset

    long lClonRecs = RS.GetRecordCount();
    long lOrigRecs = m_pRs->GetRecordCount();
    .
    .
    RS.Close();
    pRs->Close();
}

delete pRs;

    CADORecordset::SaveAsXML

    The SaveAsXML function saves the open recordset in a file with XML format.

    BOOL SaveAsXML(LPCTSTR lpstrXMLFile);

    Parameters

    LPCTSTR strXMLFile - a string that indicates the complete path name of the file where the recordset is to be saved.

    Return Value

    Returns TRUE if it was executed successfully.

    CADORecordset::OpenXML

    The OpenXML function opens a XML file format in a recordset.

    BOOL OpenXML(LPCTSTR lpstrXMLFile);

    Parameters

    LPCTSTR strXMLFile - a string that indicates the complete path name of the XML file to be opened.

    Return Value

    Returns TRUE if it was executed successfully.

    For example

    CADORecordset* pRs = CADORecordset(pDB);

if(prs->OpenXML("C://My.XML"))
{
    CString strClient = _T("");
    double dblVal = 0;
    long lrecs = prs->GetRecordCount();

    if(!prs->IsEof())
        prs->MoveFirst();

    prs->GetFieldValue("Budget", dblVal);
    prs->GetFieldValue("ClientName", strClient);

    prs->Close();
}

    CADORecordset::OpenSchema

    The OpenSchema function obtains database schema information from the provider.

    BOOL OpenSchema(int nSchema, LPCTSTR SchemaID = _T(""));
throw(CADOException);

    Parameters

    • int nSchema - A value that represents the type of schema query.
    • LPCTSTR SchemaID = _T("") - The GUID for a provider-schema query not defined by the OLE DB specification.
    Constant Value Description Constraint Columns
    schemaAsserts 0 Returns the assertions defined in the catalog that are owned by a given user.

    (ASSERTIONS Rowset)

    		 CONSTRAINT_ CATALOG*
    CONSTRAINT_ SCHEMA*
    CONSTRAINT_NAME
    schemaCatalogs 1 Returns the physical attributes associated with catalogs accessible from the DBMS.

    (CATALOGS Rowset)

    		 CATALOG_NAME
    schemaCharacterSets 2 Returns the character sets defined in the catalog that are accessible to a given user.

    (CHARACTER_SETS Rowset)

    		 CHARACTER_ SET_CATALOG*
    CHARACTER_ SET_SCHEMA*
    CHARACTER_SET _NAME*
    schemaCheckConstraints 5 Returns the check constraints defined in the catalog that are owned by a given user.

    (CHECK_CONSTRAINTS Rowset)

    		 CONSTRAINT_ CATALOG*
    CONSTRAINT_ SCHEMA*
    CONSTRAINT_NAME
    schemaCollations 3

    Returns the character collations defined in the catalog that are accessible to a given user.

    (COLLATIONS Rowset)

    		 COLLATION_ CATALOG*
    COLLATION_SCHEMA
    COLLATION_NAME
    schemaColumnPrivileges 13

    Returns the privileges on columns of tables defined in the catalog that are available to, or granted by, a given user.

    (COLUMN_PRIVILEGES Rowset)

    		 TABLE_CATALOG
    TABLE_SCHEMA
    TABLE_NAME
    COLUMN_NAME
    GRANTOR
    GRANTEE
    schemaColumns 4

    Returns the columns of tables (including views) defined in the catalog that are accessible to a given user.

    (COLUMNS Rowset)

    		 TABLE_CATALOG
    TABLE_SCHEMA
    TABLE_NAME
    COLUMN_NAME
    schemaColumnsDomainUsage 11 Returns the columns defined in the catalog that are dependent on a domain defined in the catalog and owned by a given user.

    (COLUMN_DOMAIN_USAGE Rowset)

    		 DOMAIN_CATALOG
    DOMAIN_SCHEMA
    DOMAIN_NAME
    COLUMN_NAME
    schemaConstraintColumnUsage 6 Returns the columns used by referential constraints, unique constraints, check constraints, and assertions, defined in the catalog and owned by a given user.

    (CONSTRAINT_COLUMN_USAGE Rowset)

    		 TABLE_CATALOG
    TABLE_SCHEMA
    TABLE_NAME
    COLUMN_NAME
    schemaConstraintTableUsage 7 Returns the tables that are used by referential constraints, unique constraints, check constraints, and assertions defined in the catalog and owned by a given user.

    (CONSTRAINT_TABLE_USAGE Rowset)

    		 TABLE_CATALOG
    TABLE_SCHEMA
    TABLE_NAME
    schemaCubes 32 Returns information about the available cubes in a schema (or the catalog, if the provider does not support schemas).

    (CUBES Rowset*)

    		 CATALOG_NAME
    SCHEMA_NAME
    CUBE_NAME
    schemaDBInfoKeywords 30 Returns a list of provider-specific keywords.

    (IDBInfo::GetKeywords*)

    		 <None>
    schemaDBInfoLiterals 31 Returns a list of provider-specific literals used in text commands.

    (IDBInfo::GetLiteralInfo*)

    		 <None>
    schemaDimensions 33 Returns information about the dimensions in a given cube. It has one row for each dimension.

    (DIMENSIONS Rowset*)

    		 CATALOG_NAME
    SCHEMA_NAME
    CUBE_NAME
    DIMENSION_NAME
    DIMENSION_ UNIQUE_NAME*
    schemaForeignKeys 27 Returns the foreign key columns defined in the catalog by a given user.

    (FOREIGN_KEYS Rowset)

    		 PK_TABLE_CATALOG
    PK_TABLE_SCHEMA
    PK_TABLE_NAME
    FK_TABLE_CATALOG
    FK_TABLE_SCHEMA
    FK_TABLE_NAME
    schemaHierarchies 34 Returns information about the hierarchies available in a dimension.

    (HIERARCHIES Rowset*)

    		 CATALOG_NAME
    SCHEMA_NAME
    CUBE_NAME
    DIMENSION_ UNIQUE_NAME*
    HIERARCHY_NAME
    HIERARCHY_ UNIQUE_NAME*
    schemaIndexes 12 Returns the indexes defined in the catalog that are owned by a given user.

    (INDEXES Rowset)

    		 TABLE_CATALOG
    TABLE_SCHEMA
    INDEX_NAME
    TYPE
    TABLE_NAME
    schemaKeyColumnUsage 8 Returns the columns defined in the catalog that are constrained as keys by a given user.

    (KEY_COLUMN_USAGE Rowset)

    		 CONSTRAINT_ CATALOG*
    CONSTRAINT_ SCHEMA*
    CONSTRAINT_NAME
    TABLE_CATALOG
    TABLE_SCHEMA
    TABLE_NAME
    COLUMN_NAME
    schemaLevels 35 Returns information about the levels available in a dimension.

    (LEVELS Rowset*)

    		 CATALOG_NAME
    SCHEMA_NAME
    CUBE_NAME
    DIMENSION_ UNIQUE_NAME*
    HIERARCHY_ UNIQUE_NAME*
    LEVEL_NAME
    LEVEL_ UNIQUE_NAME*
    schemaMeasures 36 Returns information about the available measures.

    (MEASURES Rowset*)

    		 CATALOG_NAME
    SCHEMA_NAME
    CUBE_NAME
    MEASURE_NAME
    MEASURE_ UNIQUE_NAME*
    schemaMembers 38 Returns information about the available members.

    (MEMBERS Rowset*)

    		 CATALOG_NAME
    SCHEMA_NAME
    CUBE_NAME
    DIMENSION_ UNIQUE_NAME*
    HIERARCHY_ UNIQUE_NAME*
    LEVEL_ UNIQUE_NAME*
    LEVEL_NUMBER
    MEMBER_NAME
    MEMBER_UNIQUE _NAME*
    MEMBER_CAPTION
    MEMBER_TYPE
    Tree operator (For more information, see the OLE DB for OLAP documentation.)
    schemaPrimaryKeys 28 Returns the primary key columns defined in the catalog by a given user.

    (PRIMARY_KEYS Rowset)

    		 PK_TABLE_CATALOG
    PK_TABLE_SCHEMA
    PK_TABLE_NAME
    schemaProcedureColumns 29 Returns information about the columns of rowsets returned by procedures.

    (PROCEDURE_COLUMNS Rowset)

    		 PROCEDURE_ CATALOG*
    PROCEDURE_SCHEMA
    PROCEDURE_NAME
    COLUMN_NAME
    schemaProcedureParameters 26 Returns information about the parameters and return codes of procedures.

    (PROCEDURE_PARAMETERS Rowset)

    		 PROCEDURE_ CATALOG*
    PROCEDURE_SCHEMA
    PROCEDURE_NAME
    PARAMETER_NAME
    schemaProcedures 16 Returns the procedures defined in the catalog that are owned by a given user.

    (PROCEDURES Rowset)

    		 PROCEDURE_ CATALOG*
    PROCEDURE_SCHEMA
    PROCEDURE_NAME
    PROCEDURE_TYPE
    schemaProperties 37 Returns information about the available properties for each level of the dimension.

    (PROPERTIES Rowset*)

    		 CATALOG_NAME
    SCHEMA_NAME
    CUBE_NAME
    DIMENSION_ UNIQUE_NAME*
    HIERARCHY_ UNIQUE_NAME*
    LEVEL_ UNIQUE_NAME*
    MEMBER_ UNIQUE_NAME*
    PROPERTY_TYPE
    PROPERTY_NAME
    schemaProviderSpecific -1 Used if the provider defines its own nonstandard schema queries. <Provider specific>
    schemaProviderTypes 22 Returns the (base) data types supported by the data provider.

    (PROVIDER_TYPES Rowset)

    		 DATA_TYPE
    BEST_MATCH
    schemaReferentialConstraints 9 Returns the referential constraints defined in the catalog that are owned by a given user.

    (REFERENTIAL_CONSTRAINTS Rowset)

    		 CONSTRAINT_ CATALOG*
    CONSTRAINT_ SCHEMA*
    CONSTRAINT_NAME
    schemaSchemata 17 Returns the schemas (database objects) that are owned by a given user.

    (SCHEMATA Rowset)

    		 CATALOG_NAME
    SCHEMA_NAME
    SCHEMA_OWNER
    schemaSQLLanguages 18 Returns the conformance levels, options, and dialects supported by the SQL-implementation processing data defined in the catalog.

    (SQL_LANGUAGES Rowset)

    		 <None>
    schemaStatistics 19 Returns the statistics defined in the catalog that are owned by a given user.

    (STATISTICS Rowset)

    		 TABLE_CATALOG
    TABLE_SCHEMA
    TABLE_NAME
    schemaTableConstraints 10 Returns the table constraints defined in the catalog that are owned by a given user.

    (TABLE_CONSTRAINTS Rowset)

    		 CONSTRAINT_ CATALOG*
    CONSTRAINT_ SCHEMA*
    CONSTRAINT_NAME
    TABLE_CATALOG
    TABLE_SCHEMA
    TABLE_NAME
    CONSTRAINT_TYPE
    schemaTablePrivileges 14 Returns the privileges on tables defined in the catalog that are available to, or granted by, a given user.

    (TABLE_PRIVILEGES Rowset)

    		 TABLE_CATALOG
    TABLE_SCHEMA
    TABLE_NAME
    GRANTOR
    GRANTEE
    schemaTables 20 Returns the tables (including views) defined in the catalog that are accessible to a given user.

    (TABLES Rowset)

    		 TABLE_CATALOG
    TABLE_SCHEMA
    TABLE_NAME
    TABLE_TYPE
    schemaTranslations 21 Returns the character translations defined in the catalog that are accessible to a given user.

    (TRANSLATIONS Rowset)

    		 TRANSLATION_ CATALOG*
    TRANSLATION_ SCHEMA*
    TRANSLATION _NAME*
    schemaTrustees 39 Reserved for future use.  
    schemaUsagePrivileges 15 Returns the USAGE privileges on objects defined in the catalog that are available to, or granted by, a given user.

    (USAGE_PRIVILEGES Rowset)

    		 OBJECT_CATALOG
    OBJECT_SCHEMA
    OBJECT_NAME
    OBJECT_TYPE
    GRANTOR
    GRANTEE
    schemaViewColumnUsage 24 Returns the columns on which viewed tables, defined in the catalog and owned by a given user, are dependent.

    (VIEW_COLUMN_USAGE Rowset)

    		 VIEW_CATALOG
    VIEW_SCHEMA
    VIEW_NAME
    schemaViews 23 Returns the views defined in the catalog that are accessible to a given user.

    (VIEWS Rowset)

    		 TABLE_CATALOG
    TABLE_SCHEMA
    TABLE_NAME
    schemaViewTableUsage 25 Returns the tables on which viewed tables, defined in the catalog and owned by a given user, are dependent.

    (VIEW_TABLE_USAGE Rowset)

    		 VIEW_CATALOG
    VIEW_SCHEMA
    VIEW_NAME

    * Ignore the spaces in these values, as they have been added to avoid page scrolling.

    Return Value

    Returns TRUE if it was executed successfully.

    For Example

    Collapse
    try
{
    CAD if(pdb.Open("Data Source=sysdevpdc;Provider=" 
                    "MSOLAP;Initial Catalog=Foodmart 2000"))
    {
        CADORecordset prs(&pdb);
        if(prs.OpenSchema(CADORecordset::schemaMeasures))
        {
            while(!prs.IsEof())
            {dset::schemaMeasures))
        {
            while(!prs.IsEof())
            {
                CString strValue;
                CString strUniqueName;
                CString strSqlColumnName;
                int nDataType = 0;
                int nValue = 0;

                prs.GetFieldValue("CUBE_NAME", strValue);
                prs.GetFieldValue("MEASURE_NAME", strValue);
                prs.GetFieldValue("MEASURE_AGGREGATOR", nValue);
                prs.GetFieldValue("MEASURE_UNIQUE_NAME", 
                                                  strUniqueName);
                prs.GetFieldValue("MEASURE_NAME_SQL_COLUMN_NAME", 
                                               strSqlColumnName);
                prs.GetFieldValue("DATA_TYPE", nDataType);
                prs.MoveNext();
            }
        }
        prs.Close();
    }
}
catch(CADOException &e)
{
...
}

    CADORecordset::Requery

    The Requery function refreshes an open recordset.

    BOOL Requery();
throw(CADOException);

    Return Value

    Returns TRUE if it was executed successfully.

    Sample 01:

    Collapse
    CADODatabase* pAdoDb = new CADODatabase();
CString strConnection = "";

strConnection = _T("Provider=MSDASQL;"
                  "PersistSecurityInfo=False;Trusted_Connection=Yes
Data Source=Access Sql Server;catalog=sampledb");

if(pAdoDb->Open((LPCTSTR)strConnection))
{
    CString strQry = _T("");
    int numRecords;

    strQry.Format(_T("sp_StoreClientFields_ps '%s', %d"), 
                  (LPCTSTR)strParam1, nParam2);

    CADORecordset* pRs = new CADORecordset(pAdoDb);

    if(!pRs->Open((LPCTSTR)strQry))
    {
    delete pRs;
    delete pAdoDb;
    return FALSE
    }

    numRecords = pRs->GetRecordCount();
    while(!pRs->IsEof())
    {
      CString strVal = _T("");
      int nVal = 0;
      //Get Numeric Field Value
      pRs->GetFieldValue("NumField1", nVal)

      //Get String Field Data
      pRs->GetFieldValue("StrField..", strVal)
        DoSomething(nVal, strVal);

        pRs->MoveNext();
    }
    pRs->Close();
}
else
  return FALSE;

    The CADOParameter Class

    The CADOParameter class has a set of functions that corresponds to the _ParameterPtr.

    CADOParameter::CADOParameter

    Creates a CADOParameter object.

    CADOParameter(int nType, long lSize = 0, int nDirection = paramInput, 
              CString strName = _T(""));

    Parameters

    • int nType - An int value that specifies the data type of the CADOParameter object. Can be one of the values specified in CADORecordset::GetFieldInfo. If you are using CADORecordset::typeNumeric or CADORecordset::typeDecimal, you must define the precision and scale values.
    • long lSize = 0 - An optional long value that specifies the maximum length for the parameter value in bytes or characters.
    • int nDirection = paramInput - An optional int value that specifies the direction of the CADOParameter object. Can be one of the following values:
      • CADOParameter::paramUnknown - Indicates that the parameter direction is unknown.
      • CADOParameter::paramInput - Default. Indicates that the parameter represents an input parameter.
      • CADOParameter::paramOutput - Indicates that the parameter represents an output parameter.
      • CADOParameter::paramInputOutput - Indicates that the parameter represents both an input and output parameter.
      • CADOParameter::paramReturnValue - Indicates that the parameter represents a return value.
      • CString strName = _T("") - An optional string that specifies the name of the CADOParameter object.

    See Sample

    CADOParameter::SetValue

    The SetValue function sets the value for the CADOParameter object.

    BOOL SetValue(int nValue);
BOOL SetValue(long lValue);
BOOL SetValue(double dbValue);
BOOL SetValue(CString strValue);
BOOL SetValue(COleDateTime time);
BOOL SetValue(_variant_t vtValue);

    Parameters

    • int nValue - An int value containing the parameter value.
    • long lValue - A long value containing the parameter value.
    • double dbValue - A double value containing the parameter value.
    • CString strValue - A string value containing the parameter value.
    • COleDateTime time - A time value containing the parameter value.
    • _variant_t vtValue - A variant value containing the parameter value.

    Return Value

    Returns TRUE if it was executed successfully.

    See Sample

    CADOParameter::SetPrecision

    The SetPrecison function sets the precision for the CADOParameter object.

    void SetPrecision(int nPrecision);

    CADOParameter::SetScale

    The SetScale function sets the scale for the CADOParameter object.

    void SetScale(int nScale);

    CADOParameter::GetValue

    The GetValue function returns the value of the CADOParameter object.

    BOOL GetValue(int& nValue);
BOOL GetValue(long& lValue);
BOOL GetValue(double& dbValue);
BOOL GetValue(CString& strValue, CString strDateFormat = _T(""));
BOOL GetValue(COleDateTime& time);
BOOL GetValue(_variant_t& vtValue);

    Parameters

    • int& nValue - A reference to an int that will store the value of the parameter.
    • long& lValue - A reference to a long that will store the value of the parameter.
    • double& dbValue - A reference to a double that will store the value of the parameter.
    • CString& strValue - A reference to a string that will store the value of the parameter.
    • CString strDateFormat = _T("") - A formatting time string similar to the strftime formatting string.
    • COleDateTime& time - A reference to a time object that will store the value of the parameter.
    • _variant_t& vtValue - A reference to a variant object that will store the value of the parameter.

    Return Value

    Returns TRUE if it was executed successfully.

    See Sample

    CADOParameter::SetName

    The SetName function sets the name of the CADOParameter object. 

    CString SetName(CString strName);

    Parameters

    CString strName - A string specifying the parameter name.

    CADOParameter::GetName

    The GetName function returns the CADOParameter object.

    CString GetName();

    CADOParameter::GetType

    The GetType function returns the type of the CADOParameter object.

    int GetType();

    CADOParameter::GetParameter

    The GetParameter function returns a pointer to a _Parameter object.

    _ParameterPtr GetParameter();

    The CADOCommand Class

    The CADOCommand class has a set of functions that corresponds to the _CommandPtr.

    CADOCommand::CADOCommand

    Creates a CADOCommand object.

    CADOCommand(CADODatabase* pAdoDatabase, CString strCommandText = _T(""),
                                  int nCommandType = typeCmdStoredProc);

    Parameters

    • CADODatabase* pAdoDatabase - A CADODatabase object pointer.
    • CString strCommandText = _T("") - An optional string that indicates the text of the CADOCcommand object.
    • int nCommandType = typeCmdStoredProc - An optional int value that indicates the type of the CADOCommand object. Can be one of the following values:
      • CADOCommand::typeCmdText - Evaluates CommandText as a textual definition of a command or stored procedure call.
      • CADOCommand::typeCmdTable - Evaluates CommandText as a table name whose columns are all returned by an internally generated SQL query.
      • CADOCommand::typeCmdTableDirect - Evaluates CommandText as a table name whose columns are all returned.
      • CADOCommand::typeCmdStoredProc - Default. Evaluates CommandText as a stored procedure name.
      • CADOCommand::typeCmdUnknown - Indicates that the type of the command in the CommandText property is not known.
      • CADOCommand::typeCmdFile - Evaluates CommandText as the file name of a persistently stored recordset. Used with Recordset.Open or Requery only.

    See Sample

    CADOCommand::AddParameter

    The AddParameter function.

    Collapse
    BOOL AddParameter(CADOParameter* pAdoParameter);
BOOL AddParameter(CString strName, int nType, int nDirection,
                          long lSize, int nValue);
BOOL AddParameter(CString strName, int nType, int nDirection,
                          long lSize, long lValue);
BOOL AddParameter(CString strName, int nType, int nDirection,
                          long lSize, double dblValue, int nPrecision = 0,
                          int nScale = 0);
BOOL AddParameter(CString strName, int nType, int nDirection,
                          long lSize, CString strValue);
BOOL AddParameter(CString strName, int nType, int nDirection,
                          long lSize, COleDateTime time);
BOOL AddParameter(CString strName, int nType, int nDirection,
                          long lSize, _variant_t vtValue, int nPrecision = 0,
                          int nScale = 0);

    Parameters

    • CADOParameter* pAdoParameter - A pointer to a CADOParameter object.
    • CString strName - A string that specifies the name of the parameter.
    • int nType - An int value that specifies the data type of the CADOParameter object. Can be one of the values specified in CADORecordset::GetFieldInfo. If you are using CADORecordset::typeNumeric or CADORecordset::typeDecimal, you must define the precision and scale values.
    • int nDirection - An int value that specifies the direction of the CADOParameter object. Can be one of the values specified in CADOParameter::CADOParameter.
    • long lSize - A long value that specifies the maximum length for the parameter value in bytes or characters.
    • int nValue - An int value containing the parameter value.
    • long lValue - A long value containing the parameter value.
    • double dblValue - A double value containing the parameter value.
    • int nPrecision - An int value containing the precision of the parameter value.
    • int nScale - An int value containing the scale of the parameter value.
    • CString strValue - A string value containing the parameter value.
    • COleDateTime time - A time value containing the parameter value.
    • _variant_t vtValue - A variant value containing the parameter value.

    Return Value

    Returns TRUE if it was executed successfully.

    See Sample

    CADOCommand::SetText

    The SetText function sets the command text of the CADOCommand object.

    void SetText(CString strCommandText);

    Parameters

    CString strCommandText - A string that indicates the command text.

    CADOCommand::GetText

    The GetText function returns the command text of the CADOCommand object.

    CString GetText();

    CADOCommand::SetType

    The SetType function sets the type of the CADOCommand object.

    void SetType(int nCommandType);

    Parameters

    int nCommandType - A int value that indicates the type of the command.

    CADOCommand::GetType

    The GetType function returns the type of the CADOCommand object.

    int GetType();

    CADOCommand::GetCommand

    The GetCommand function returns a Command pointer.

    _CommandPtr GetCommand();

    CADOCommand::Execute

    The Execute function executes a command text.

    BOOLExecute();

    Return Value

    Returns TRUE if it was executed successfully.

    CADOCommand::GetRecordsAffected

    The GetRecordsAffected function returns the number of records affected by the last command executed.

    int GetRecordsAffected();

    Sample 02:

    Collapse
    //SQL SCRIPT...
Create Procedure sp_OutputTest
@IN1 int,
@OutInt int Output,
@OutChar varchar(20) Output
As   
    SELECT    
        @OutChar = 'Hello World'
    SELECT    
        @OutInt = 10 * @IN1
    return (90)
GO


//Visual C++ Code...

CADOParameter pParamRetVal(CADORecordset::typeInteger, sizeof(int),
                           CADOParameter::paramReturnValue);
CADOParameter pParamIn(CADORecordset::typeInteger, sizeof(int));
CADOParameter pParamOutInt(CADORecordset::typeInteger, sizeof(int),
                           CADOParameter::paramOutput);
CADOParameter pParamOutChar(CADORecordset::typeChar, sizeof(char) * 20,
                            CADOParameter::paramOutput);

pParamIn.SetValue(2);

CADOCommand pCmd(&pDb, "sp_OutputTest");

pCmd.AddParameter(&pParamRetVal);
pCmd.AddParameter(&pParamIn);
pCmd.AddParameter(&pParamOutInt);
pCmd.AddParameter(&pParamOutChar);

CADORecordset* prs = new CADORecordset(pDb);

if(pRs->Execute(&pCmd))
{
    int nVal = 0;
    int nRetVal = 0;
    CString str = _T("");

    pParamRetVal.GetValue(nRetVal);
    pParamOutInt.GetValue(nVal);
    pParamOutChar.GetValue(str);
}

delete pRS;

    The CJectEngine Class

    The CJetEngine class has a set of functions that corresponds to the _RecordsetPtr.

    CJetEngine::CompactDatabase

    Compacts an Access database.

    BOOLCompactDatabase(CString strDatabaseSource, CString strDatabaseDestination)

    Parameters

    • CString strDatabaseSource - A connection string to the source database.
    • CString strDatabaseDestination - A connection string to the destination database.

    Remarks:

    The connection strings must be like this: "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:/the Database Path".

    Return Value

    Returns TRUE if it was executed successfully.

    For example

    CString strCompactedDBConnection;
CString strConnection;

CString strCompactedDBPath = _T("C://My Projects//Database//SampleDB.tmp");
CString strDatabasePath = _T("C://My Projects//Database//SampleDB.mdb");

strCompactedDBConnection.Format("Provider=Microsoft.Jet.OLEDB." 
        "4.0;Data Source=%s", strCompactedDBPath.GetBuffer(0));
strConnection.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=%s", 
                                         strDatabasePath.GetBuffer(0));
if(CJetEngine::CCompactDatabase(strConnection, strCompactedDBConnection))
{
    ::CopyFile(strCompactedDBPath.GetBuffer(0), 
          strDatabasePath.GetBuffer(0), FALSE);
}

    The CADOException Class

    The CADOException class represents an exception condition. The class includes public data members you can use to determine the cause of the exception.

    CADOException::CADOException

    Creates a CADOException object.

    CADOExcpetion();

    To retrieve the ADO error information:

    • Construct a CADOException object.
    • Call any exception object’s GetErrorMesaage or GetError member function, to retrieve information about the error, via the exception object.

    For Example

    try
{
    if(pDb.Open(_T("Provider=Microsoft.JET.OLEDB.4.0;") 
                _T("Data source = c://vc projects//ado//dbTest.mdb;")))
    {
        CADORecordset pRS(&pDb);

        if(pRS.Open("tbltest", CADORecordset::openTable))
        {
            pRS.SetSort("Descriptions");
            .
            .
            .
        }
        pRS.Close();
    }
}
catch(CADOException &e)
{
    AfxMessageBox(e.GetErrorMessage());
}

    CADOException::GetErrorMessage

    CString GetErrorMessage() const;

    Return Value

    Returns error description.

    See Sample

    CADOException::GetError

    long GetError();

    Return Value

    Returns the error code.

    CADOException::SetError

    void SetError(long lErrorCode = 0);
void SetErrorMessage(LPCSTR lpstrError = _T(""));

    Parameters

    • long lErrorCode = 0 - A long value containing the error code.
    • LPCSTR lpstrError = _T("") - A string value containing the error description.

    The COLEDBDataLink Class

    The COLEDBDataLink class is an utility class to create and edit datalinks.

    COLEDBDataLink::COLEDBDataLink

    Creates a COLEDBDataLink object.

    COLEDBDataLink();

    COLEDBDataLink::New

    CString New(HWND hWnd = NULL);
throw(COLEDBException);

    Parameters

    HWND hWnd = NULL - The parent window handle.

    Return Value

    Returns a string informing the connection string corresponding to the created connection.

    See Sample

    COLEDBDataLink::Edit

    void Edit(LPCSTR lpstrConnectionString, HWND hWnd);
throw(COLEDBException);

    Parameters

    • LPCSTR lpstrConnectionString
    • HWND hWnd - The parent window handle.

    For Example

    COLEDBDataLink dtlnk;

try
{
    dtlnk.Edit("Provider=Microsoft.JET.OLEDB.4.0;Data source" 
               " = c://vc projects//ado//dbTest.mdb;", this->m_hWnd);
}
catch(COLEDBException &e)
{
    AfxMessageBox(e.GetErrorMessage());
}

    The COLEDBException Class

    The COLEDBException class represents an exception condition. The class includes public data members you can use to determine the cause of the exception.

    COLEDBException::COLEDBException

    Creates a COLEDBException object.

    COLEDBException();

    To retrieve the OLEDB error information:

    • Construct a COLEDBException object.
    • Call any exception object’s GetErrorMessage or GetError member function to retrieve information about the error, via the exception object.

    For Example

    CADODatabase pDb;
COLEDBDataLink dtlnk;

try
{
    pDb.Open(dtlnk.New(this->m_hWnd));
}
catch(COLEDBException &e)
{
    AfxMessageBox(e.GetErrorMessage());
}

    COLEDBException::GetErrorMessage

    CString GetErrorMessage() const;

    Return Value

    Returns error description.

    See Sample

    COLEDBException::GetError

    long GetError();

    Return Value

    Returns the error code.

    COLEDBException::SetError

    void SetError(long lErrorCode = 0);
void SetErrorMessage(LPCSTR lpstrError = _T(""));

    Parameters

    • long lErrorCode = 0 - A long value containing the error code.
    • LPCSTR lpstrError = _T("") - A string value containing the error description.

    Common Questions:

    How Bind the MS DataGrid Control to CADORecordset:

    • First: You need to add the MS DataGrid Control to your application.
    • Second: Apply the CADORecordset::GetRecordset function to the SetRefDataSource function of the data control class. 
    if(m_pRs.Open("tblTest", CADORecordset::openTable))
{
    //m_datagridctrl is the CDataGrid Class...

    m_datagridctrl.SetCaption("Clients");
    m_datagridctrl.SetRefDataSource(NULL);
    m_datagridctrl.SetRefDataSource((LPUNKNOWN)m_pRs.GetRecordset());
    m_datagridctrl.Refresh();
}

    For reference on how to add a data control to your project, please see this article by Rashid Thadha.

    How do I re-sort a Recordset?

    The answer is easy. You have several functions and properties that are part of _RecordsetPtr. Using CADORecordset::GetRecordset(), you get a pointer to _RecordsetPtr. You can use it for setting the Sort property.

    Note: You don't need to use _RecordsetPtr::Refresh().

    if(m_pRs.Open("tblTest", CADORecordset::openTable))
{
    m_pRs.GetRecordset()->PutSort("Field01 DESC");
}

    Now: you have the function CADORecordset::SetSort();

    fatal error C1010: unexpected end of file while looking for precompiled header directive

    For solving this common problem, you need to use automatic use of precompiled headers. Select Project/Settings (or ALT+F7) then, in the Project Settings dialog, select the C/C++ tab, then select the Precompiled Headers item in the combo box, and select the Automatic use of precompiled headers option.

    How do you get the return codes from your stored procedures in SQL Server?

    You must use the CADOParameter class. CADOParameter::paramReturnValue gets the value that is returned by the stored procedure. It always must be an integer and must be in the first place in the list of parameters. If you are not using parameters for input or output, you only need to use this parameter....

    See Sample

    I've been trying to work with the CADOCommand class and be able to pass in a UUID field. I've not been very successful so far. Do you by chance have an example that shows this?

    You are talking about uniqueidentifier type field? Okay, the problem is the following:

    First you can update the table using the SQL syntax NEWID(). That command will do for you a unique identifier string like: "{B6B83A8C-F92C-4FA7-9641-631143E6056C}"... If you want to insert data into that type of field you need to use a string like that... In conclusion we can say: you need to use a string parameter type, with the GUID format, and it must be unique... Aren't there a lot of conditions!!!...

    But I wrote a sample: In the following sample, you can see that I used the UUID parameter as string. You can see in the stored procedure that the parameter is of uniqueidentifier type.

    //Visual C++ Sample
CADOParameter pParamRet(CADORecordset::typeInteger, sizeof(int),
                        CADOParameter::paramReturnValue);
CADOParameter pParamInChar(CADORecordset::typeChar, sizeof(char) * 40,
                           CADOParameter::paramInput);
CADOParameter pParamID(CADORecordset::typeInteger, sizeof(int));

CString strUUID = CString("{B6B83A8C-F92C-4FA7-9641-631143E6056C}");
pParamInChar.SetValue(strUUID);
pParamID.SetValue(1);
CADOCommand pCmd(&m_pDB, "sp_UUIDTest");

pCmd.AddParameter(&pParamRet);
pCmd.AddParameter(&pParamInChar);
pCmd.AddParameter(&pParamID);

if(pRs.Execute(&pCmd))
{
    int nVal = 0;
    pParamRet.GetValue(nVal);
}
    //SQL SCRIPT
Create Procedure sp_UUIDTest
@UUID uniqueidentifier = NULL,
@ID integer
AS
    UPDATE
        systable01
    SET
        UUID = @UUID
    WHERE
        sysfield00 = @ID
    
    if @@Error = 0
        return 1
    else
        return 99
GO

    ADO and ADOX together

    I receive several emails per day asking me how I can use the ADO and ADOX classes together. The answer is, right now, from version 2.10 of ADO, you can use the two types of classes together. For this, you must include the headers and CPP files of each class and then must include the headers in the project.

    Remarks

    It's very important to verify that the includes must be in the following order. First the ADOX classes header and then the ADO classes header.

    #include <adox.h>
#include <ado2.h>

    Carlos A. Antollini.

    Updates

    • 25 Apr 2001 - Version 1.0 released.
    • 20 May 2001 - Version 1.1

      Added the following functions:

      • AbsolutePage, GetPageCount, PageSize, AbsolutePosition, GetFieldInfo, GetChunk, GetString.
    • 29-Jun-2001 - Version 1.2

      Added the following functions:

      • AddNew, Edit, Delete, Update, CancelUpdate, SetFieldValue, Find, FindFirst, FindNext, SetBookmark, GetBookmark.
    • 29-Sept-2001 - Version 1.25
      • Added support for SQL Server 2000.
      • Corrected bug reported by Robert Pittenger for empty fields.
    • 10-Oct-2001 - Version 1.30
      • Corrected bug reported by Giles Forster and Rainer Mangold in SetFieldValue for empty fields.
      • Added the data type enum.
    • 05-Nov-2001 - Version 1.37
      • Update for adding capacity to bind the DataGrid to CADORecodset.
      • Added function GetLastErrorString and changed the data type returned by GetLastError.
      • Added functions Clone and SetFilter (petitioned by Marcel Stoica).
    • 15-Jan-2002 - Version 1.40
      • Added the new GetChunk and AppendChunk functions written by Giles Forster.
    • 15-Feb-2002 - Version 1.45
      • Corrected bug reported by J. C. Martinez Galán in decimal fields.
      • Added XML support.
    • 04-Apr-2002 - Version 2.00
      • Added CADOParameter and CADOCommand classes.
    • 14-May-2002 - Version 2.01
      • Added COleCurrency and bool in CADORecordset::GetFieldValue and CADORecordset::SetFieldValue.
    • 25-July-2002 - Version 2.04
      • Added CADODatabase::GetRecordsAffcetd, CADOCommand::GetRecordsAffected, CADOCommand::Execute, CADOParameter::SetPrecision, CADOParamater::SetScale and bug corrected in CADOCommand::AddParameter.
    • 2-July-2003 - Version 2.10
      • Added compatibility with the ADOX classes to be used together. (Petitioned by hundreds of users.)
      • Added CADODatabase::SetConnectionMode, CADORecordset::OpenSchema.
      • Added CJetEngine::CCompactDatabase.
    • 2-October-2003 - Version 2.11
      • Memory leak in CADOCommand fixed by Jan Stocker.
    • 08-August-2004 - COLEDBDataLink was created under Version 1.01.
      • COLEDBDataLink class was created, and added to ADO classes.
    • 10-Februry-2005 - Version 2.15
      • CADOException class was added.

    Special thanks

    These classes received many suggestions from the users. Thanks to all for your collaboration.

    • Rainer Mangold
    • Christian Graus
    • Mike Osbahr
    • Francis BONTHOUX
    • Spiros Prantalos
    • Robert Pittenger
    • Giles Forster
    • Rob Sandhu
    • Marcel Stoica
    • Daniel Berman
    • Jan Stocker
    • And tons of people requesting for new versions.
     
  • 相关阅读:
    学习MeteoInfo二次开发教程（十一）
    学习MeteoInfo二次开发教程（十）
    学习MeteoInfo二次开发教程（九）
    学习MeteoInfo二次开发教程（八）
    linux 03 命令 续
    linux 02 基础命令
    linux 01 基础命令
    第九节课 迭代器生成器、模块和包
    第八节课 文件、异常、文件的输入输出
    第七节课 内置函数、作用域、闭包、递归
  • 原文地址：https://www.cnblogs.com/rainbowzc/p/2422280.html
Copyright © 2011-2022 走看看