How to use ms access database in C++?

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How to link database to my project code in win32.Yesterday i saw below link 

https://msdn.microsoft.com/en-us/library/office/ff965871(v=office.14)#DataProgrammingWithAccess2010_ATLOLEDBExample 

but no use above code.Please help me?
Thanks in advance

What I have tried:

I tried above link with different databases but not work.

This link also not work

https://msdn.microsoft.com/en-us/library/cc811599.aspx#Y3869

[EDIT by Jochen Arndt: Inserted code and text posted as solution]

C++

#import "C:\Program Files\Common Files\System\ADO\msado15.dll" \
no_namespace rename("EOF", "EndOfFile")

hr=S_OK;
try
{
    CoInitialize(NULL);
    _bstr_t strCnn("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\\Sankar\\Database1.accdb");
    _RecordsetPtr pRstAuthors=NULL;
     
    _ConnectionPtr  pConnection=NULL;
     
    // Call Create instance to instantiate the Record set
    hr = pRstAuthors.CreateInstance(__uuidof(Recordset));
    pConnection.CreateInstance(_uuidof(Connection));
    pConnection->ConnectionString="Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\\Sankar\\Database1.accdb";
    pConnection->ConnectionTimeout = 30;  
    if(FAILED(hr))
    {
        // printf("Failed creating record set instance\n");
        return;
    }
    //Open the Record set for getting records from Customer table
    pRstAuthors->Open("SELECT* FROM Customers","Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\\Sankar\\Database1.accdb",adOpenStatic,adLockReadOnly, adCmdText);
 
    _bstr_t valField1;
    int valField2;
    pRstAuthors->MoveFirst();
    if (!pRstAuthors->EndOfFile)
    {
        while(!pRstAuthors->EndOfFile)
        {
            valField1 = pRstAuthors->Fields->GetItem("username")->Value.intVal;
        }
    }
}
catch(_com_error & ce)
{
    //sprintf("Error:%s\n",ce.Description);
}
CoUninitialize();

pRstAuthors->Open: In this method i got error.
[/EDIT]

Posted 7-Aug-17 18:50pm

sankars3

Updated 7-Aug-17 23:27pm

Jochen Arndt

v3

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Comments

Richard MacCutchan 8-Aug-17 3:39am

What does "no use above code" mean?

Richard MacCutchan 8-Aug-17 5:30am

Why are you hard coding the connection string in three different places?

Richard MacCutchan 8-Aug-17 5:33am

You are calling a method on pRstAuthors but you never initialise it to point to anything. And looking at the rest of the code there are other similar errors. Did you actually write this code or is it just copied from the internet even though incomplete?

2 solutions

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RickZeeland · Answer 1 · 2017-08-07T21:26:00

Solution 1

See this article: Developing Access 2007 Solutions with Native C or C++[^]
See here for connection details with Provider=Microsoft.ACE.OLEDB.12 : Microsoft ACE OLEDB 12.0 Connection Strings - ConnectionStrings.com[^]

Example:

C#

_bstr_t strCnn("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\\Sankar\\Database1.accdb;Persist Security Info=False;");

Posted 7-Aug-17 21:26pm

RickZeeland

Updated 9-Aug-17 3:20am

v3

Comments

sankars3 8-Aug-17 5:23am

#import "C:\Program Files\Common Files\System\ADO\msado15.dll" \
no_namespace rename("EOF", "EndOfFile")

hr=S_OK;
try
{
CoInitialize(NULL);
_bstr_t strCnn("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\\Sankar\\Database1.accdb");
_RecordsetPtr pRstAuthors=NULL;

_ConnectionPtr pConnection=NULL;

// Call Create instance to instantiate the Record set
hr = pRstAuthors.CreateInstance(__uuidof(Recordset));
pConnection.CreateInstance(_uuidof(Connection));
pConnection->ConnectionString="Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\\Sankar\\Database1.accdb";
pConnection->ConnectionTimeout = 30;

if(FAILED(hr))
{
// printf("Failed creating record set instance\n");
return;
}

//Open the Record set for getting records from Customer table

pRstAuthors->Open("SELECT* FROM Customers","Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\\Sankar\\Database1.accdb",adOpenStatic,adLockReadOnly, adCmdText);

_bstr_t valField1;
int valField2;

pRstAuthors->MoveFirst();

if (!pRstAuthors->EndOfFile)
{

while(!pRstAuthors->EndOfFile)
{
valField1 = pRstAuthors->Fields->GetItem("username")->Value.intVal;
}
}
}
catch(_com_error & ce)
{

//sprintf("Error:%s\n",ce.Description);
}
CoUninitialize();

above code i got a error pRstAuthors->Open method.Please help RickZeeland.Thanks for advacne.

RickZeeland 8-Aug-17 5:34am

You might need to add 'Persist Security Info=False;'

sankars3 9-Aug-17 9:14am

where i put this one.please help me?

Jochen Arndt · Answer 2 · 2017-08-07T21:43:00

Solution 2

It is all contained in the link from your question.

You have to decide which method you want to use:

Direct DAO (Win32)
ATL OLE DB (ATL/MFC)
ADO (Win32)
Direct ODBC (Win32)
MFC ODBC (MFC)

The Win32 methods require importing of a DLL which might be a bit tricky to avoid name conflicts.

Depending on the used method it might be necessary to ship additional packages with your application to ensure that the used database interface is installed on the client (Microsoft Access Redistributables or MDAC which should be present with all recent Windows versions since Vista/7).

See also the notes about 32/64 bit. If possible build a 32-bit application.

DAO provides the best support (more functions than the other methods). When using MFC, there are classes for OLE DB and ODBC which reduces the amount of code to write.

If you got stuck with a specific method, ask again or update your question with a short code example and a detailed problem description. "Not work" does not mean anything to us; especially when not having a single piece of code and an error message.

[EDIT: For code posted meanwhile]
If a function returns some kind of status / error, check that and report errors immediately. Your code snippet does not do that for all functions and reports errors sometimes after calling other function meanwhile. Read also the documentation for the used function to know which parameters has to be passed.

You have also to follow the examples regarding the order of the functions to be called:

Create a _ConnectionPtr
Open the connection
Create a RecordsetPtr
Open the recordset passing the connection

In detail:

pRstAuthors->Open("SELECT* FROM Customers","Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\\Sankar\\Database1.accdb",adOpenStatic,adLockReadOnly, adCmdText);

is not a valid call. It misses passing the connection. It must be:

pRstAuthors->Open("SELECT* FROM Customers","Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\\Sankar\\Database1.accdb",
_variant_t((IDispatch *) pConnection, true),
adOpenStatic,
adLockReadOnly, 
adCmdText);

[/EDIT]

Posted 7-Aug-17 21:43pm

Jochen Arndt

Updated 7-Aug-17 23:48pm

v2

Comments

sankars3 8-Aug-17 4:24am

Yesterday I Used ATL OLEDB and ADO and Direct ODBC.These three databases not worked properly in my system.

Mohibur Rashid 8-Aug-17 4:36am

Not worked properly is not enough to offer help. You need to share the error message too

Jochen Arndt 8-Aug-17 4:50am

I have used all these methods in the past. So they do work.

If they do not work for you, you must have made something wrong.
But we can't help you while you did not tell us in detail what you have done and what you got (especially full error message and where that occured).

sankars3 8-Aug-17 5:11am

hr = dbDataSource.OpenFromInitializationString(lpcOleConnect);
in above code i got error.In that i tried different methods

hr=dbDataSource.OpenFromFile(lpoleConnect);
Thanks for your help Jochen Arndt..

sankars3 8-Aug-17 5:57am

error:CoInitialized not called in datasource.

Jochen Arndt 8-Aug-17 6:15am

In your code that I have moved to your question you are calling CoInitalize().
But that return a status code too which can be checked. You should also move that call out of the try block.

It is also recommended to call CoInitalizeEx().

sankars3 8-Aug-17 6:25am

thank u.Please find the below link.
https://stackoverflow.com/questions/45539782/how-to-acess-database-in-win32

sankars3 9-Aug-17 6:02am

hr = 0x80040154 class not registered whenver i called this error happened?
Thanks in advance.

Jochen Arndt 9-Aug-17 6:33am

At which call for which class?

It generally means that the class referenced by your application (e.g. with CreateInstance) can not be found because the DLL that contains that class is not present on your system or has not been registered.

Depepending on that you have to ensure that the DLL is present and has been registered. Possible reasons:
- DLL not present: Install it (e.g. Access redistributables, MDAC, etc)
- Registration lost (may happen with older Windows versions): Repair installation or re-install
- App / registered DLL version does not match (32/64 bit)
- App is 64 bit: If the class is only available as 32-bit, you have to create a 32-bit app

sankars3 9-Aug-17 8:57am

very thanks jochen Arndt.I will check..

sankars3 9-Aug-17 9:11am

#include <string>
#include <windows.h>
#include "StdAfx.h"
#include "DatabaseHandler.h"

using namespace std;

#import "C:\Program Files\Common Files\System\ADO\msado15.dll" \
no_namespace rename("EOF", "EndOfFile")

HRESULT hr;

CDatabaseHandler::CDatabaseHandler(void)
{
hr=S_OK;
CoInitialize(0);
try
{

_bstr_t strCnn("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\\Sankar\\Database1.accdb;");
_RecordsetPtr pRstAuthors=NULL;

_ConnectionPtr pConnection=NULL;

// Call Create instance to instantiate the Record set
hr = pRstAuthors.CreateInstance(__uuidof(Recordset));

if(FAILED(hr))
{

return;
}

//Open the Record set for getting records from Customer table

//pRstAuthors->raw_Open("SELECT* FROM Customers;",strCnn,adOpenStatic,adLockReadOnly, adCmdText);
pRstAuthors->Open("SELECT* FROM Customers;",strCnn,adOpenStatic,adLockReadOnly, adCmdText);

_bstr_t valField1;
int valField2;

pRstAuthors->MoveFirst();

if (!pRstAuthors->EndOfFile)
{

while(!pRstAuthors->EndOfFile)
{
valField1 = pRstAuthors->Fields->GetItem("username")->Value.intVal;
}
}
}
catch(_com_error & ce)
{
//ce.Description;
MessageBoxA(NULL,"hello","hello",0);
//sprintf("Error:%s\n",ce.Description);
}
CoUninitialize();
}

CDatabaseHandler::~CDatabaseHandler(void)
{

}
void CDatabaseHandler::fnCallback()
{

}

this is one class of win32 project.Whenver the application start.it was called.
Above code was worked console application.but same code not worked in win32 Application.

Jochen Arndt 9-Aug-17 9:28am

Then check where are the differences between the two versions. The "Not registered" error is not related to the project type (besides the already mentioned 32/64 bit problem).