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Database » Database » ADO     Intermediate

A set of ADO classes - version 2.20

By Carlos Antollini

Simple database access using an ADO class. 		SQL, VC6, C++Windows, NT4, Win2K, SQL Server, MFC, ADO, VS6, Visual Studio, DBA, Dev

Posted: 24 Apr 2001
Updated: 6 Sep 2005
Views: 1,220,749
Bookmarked: 493 times
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5

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:

//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.

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.

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

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:

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.

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:

//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.