Executing stored procedure

How do I execute a stored procedure (from MS SQL Server 7)?
Can it be done using CRecordset or CDatabase?
ranmanorAsked:
Who is Participating?

Improve company productivity with a Business Account.Sign Up

x
 
christophmConnect With a Mentor Commented:
I wrote this sometime ago to document a NUMBER! of MFC-SQL topics, I have tried to remove everything EXCEPT the parameterized query stuff, I think I got it cleaned up pretty well.     ----   christophm

You will find following in this order :
1 a (parameterized) stored procedure
2 changes to the recordset class derived from CRecordset, created by the Wizard
3 changes to the implementation file (.CPP) for the user Recordset
4 changes to the ‘DoDataExchange()’ function.
5 the implementation code to make it happen


FIRST - Here is the stored procedure. ‘project_id’ is the parameter I will pass from my program when I invoke this stored procedure.

CREATE PROCEDURE sp_Area
  @projectid char(10)
AS
(
select  area,
        Labor, Material,Purchase,
        description as description1,
  from area      
where area.project = @projectid
) order by area


SECOND - Here is the Recordset class - these are changes to the recordset class .H file.  ** NOTE that ‘m_ProjectParameter’ is added AFTER the  “//}}AFX_FIELD”  that is, it is added after the Wizard stuff !

class spArea : public CRecordset
{
public:
           spArea(CDatabase* pDatabase = NULL);
           DECLARE_DYNAMIC(spArea)

// Field/Param Data
//{{AFX_FIELD(spAreaGroupDetail, CRecordset)
Cstring           m_Area;
CString           m_Labor;
CString           m_Material;
CString           m_Purchase;
CString           m_Description1;
//}}AFX_FIELD
CString m_ProjectParameter;  // added by ME


THIRD – Recordset implementation file (.CPP) changes

Note - There is no initialization for m_ProjectParameter (though having one would not cause any problem, it merely contributes nothing as later I will set m_ProjectParameter to a meaningful value).  
Note - 'm_nParams' is set to 1 at the end.  'm_nParams'  is a member of CRecordset and its default value is zero.  You won't find m_nParams in the class definition for spAreaGroupDetail, it is a data member of CRecordset.  'm_nParams' is the count of parameters, this example has only a single parameter, "m_ProjectParameter" so ' m_nParams' is one.
Note - 'm_nDefaultType'  is set to snapshot it is immaterial what it is set to, anything the compiler will take is OK – since I override it explicitly in the 'Open()' for the recordset..

spAreaGroupDetail::spAreaGroupDetail(CDatabase* pdb)
           : CRecordset(pdb)
{
//{{AFX_FIELD_INIT(spAreaGroupDetail)
m_Area = _T("");
m_Labor = _T("");
m_Material = _T("");
m_Purchase = _T("");
m_Description1 = _T("");
m_nFields = 5;
//}}AFX_FIELD_INIT
m_nParams  = 1;
m_nDefaultType = snapshot;
}


I made no no chages to the ‘GetDefaultSQL()’ function member – I am going to override it anyway in the ‘Open()’


FOURTH Changes to 'DoFieldExchange()' .  This is another place where I made the changes outside the wizard bracketed code; i.e., the change follows “//}}AFX_FIELD_MAP”  BTW - I checked the wizard after making all these changes and though the wizard would not do this work for me it accepts it and displays correctly.

After the closing {{AFXxxxx}} demarcation/comment you see there are two added lines, the 'pFX->SetFieldType()' to change the ‘FieldType’ from 'outputColumns'  to 'param' and the 'RFX_Text()' to map the parameter(s).
 
These two statements :    pFX->SetFieldType(CFieldExchange::param);
                          RFX_Text(pFX, "project", m_ProjectParameter);

The parameter "project" in the ‘RFX_Text’ statement exists (only?) to satisfy the syntax requirements of the 'RFX_Text()' function - I never use it.


void spAreaGroupDetail::DoFieldExchange(CFieldExchange* pFX)
{
//{{AFX_FIELD_MAP(spArea)
pFX->SetFieldType(CFieldExchange::outputColumn);

RFX_Text(pFX, _T("[Area]"), m_Area);
RFX_Text(pFX, _T("[Purchase]"), m_OBGT_Purchase);
RFX_Text(pFX, _T("[Labor]"), m_OBGT_Labor);
RFX_Text(pFX, _T("[Material]"), m_OBGT_Material);
RFX_Text(pFX, _T("[Description1]"), m_Description1);
//}}AFX_FIELD_MAP
 
pFX->SetFieldType(CFieldExchange::param);
RFX_Text(pFX, "project", m_ProjectParameter);
}
 
FIFTH - Here is the code for the gimme-the-data from the database.  Note the strange syntax of the SQL string, there must be one '(?)' for each replaceable parameter.

// instantiate a recordset object matching the recordset we clunked up
spArea     spRecordset(NULL);

// define a SQL string NOTE the syntax !!
CString           csSQL = "{CALL sp_AreaGroupDetail (?)}";

// set the parameter(s)
spRecordset.m_ProjectParameter = pApp->m_cCurrentProject;

// open the recordset (note that the type - snapshot - and the SQL string
// are explicitly passed as parameters thus bypassing the default recordset
// type and bypassing the default connect SQL,
spRecordset.Open(CRecordset::snapshot, csSQL);

// loop through the recordset until EOF
while (!spRecordset.IsEOF())
{
                      … do loop processing here …

  // get the next row from the rowset
  spRecordset.MoveNext();
}

// put the recordset away
    spRecordset.Close();


It took me a while to make this work --  good luck !  -  christophm
0
 
eknguyenCommented:
Yes you can use CDatabase e.g.,

CDatabase db;
LPCTSTR lpszSQL = _T("YOUR STORED PROCEDURE NAME");

try
{
    db.Open(NULL); //or use OpenEx(...) member
    db.ExecuteSQL(lpszSQL);
}
catch(CDBException * pE)
{
    pE->ReportError();
    pE->Delete();
}

Hope this will help
0
 
eknguyenCommented:
Yes you can use CDatabase e.g.,

CDatabase db;
LPCTSTR lpszSQL = _T("YOUR STORED PROCEDURE NAME");

try
{
    db.Open(NULL); //or use CDatabase OpenEx(...) member function
    db.ExecuteSQL(lpszSQL);
}
catch(CDBException * pE)
{
    pE->ReportError();
    pE->Delete();
}

Hope this will help
0
Get expert help—faster!

Need expert help—fast? Use the Help Bell for personalized assistance getting answers to your important questions.

 
ranmanorAuthor Commented:
How do I use parameters?
0
 
eknguyenCommented:
CDatabase db;
CString lpszSQL;
int nParam1,nParam2;
lpszSQL.Format(_T("YourStoredProcedure '%d', '%d'"),nParam1, nParam2);

try
{
    db.Open(NULL); //or use CDatabase OpenEx(...) member function
    db.ExecuteSQL(lpszSQL);
}
catch(CDBException * pE)
{
    pE->ReportError();
    pE->Delete();
}
0
 
eknguyenCommented:

The above example is for a stored procedure that do not return any value.  If you want to execute a stored procedure that return values, refer to Recordset: Parameterizing a Recordset (ODBC) in Visual C++ Programmer's Guide.

0
 
ch_vasuCommented:
CDatabase db;
CString lpszSQL;
int nParam1,nParam2;
lpszSQL.Format(_T("EXECUTE  YourStoredProcedure '%d', '%d'"),nParam1, nParam2);

try
{
    db.Open(NULL); //or use CDatabase OpenEx(...) member function
    db.ExecuteSQL(lpszSQL);
}
catch(CDBException * pE)
{
    pE->ReportError();
    pE->Delete();
}
0
 
christophmCommented:
I have several occurrences of
  'spAreaGroupDetail'  
in the above discussion, please change them to
  'spArea'

thanks  ! - christoph-m
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.