VC ++ uses ADO to connect to the SQL Server database

Basic steps:

1. Create a dialog box-based application adodatabase.

2. Create an ADO class library for connection. In the system menu, insert-> new class, and select generic class for class type. After name, enter the class name "adoconn" and click OK. In this way, the adoconn. h and adoconn. cpp files are automatically generated on the project.

3. in adoconn. import An ADO dynamic link library msado15.dll in H and add the code: # import "C: \ Program Files \ common files \ System \ ADO \ msado15.dll" no_namespace Rename ("EOF ", "adoeof") Rename ("Bof", "adobof"), at the same time in adoconn. h defines public: // Add a pointer to the connection object: _ connectionptr m_pconnection; // Add a pointer to the recordset object: _ recordsetptr m_precordset.

4. m_pconnection-> open (_ bstr_t connectionstring, _ bstr_t userid, _ bstr_t password, Long Options) operation. Connectionstring is the ADO settings in SQL Server in VC ++. For example, provider = sqloledb; Integrated Security = sspi; persist Security info = false; initial catalog = suntest; Data Source = WWW-ED1F301E78B; user id = sa; Password =;

Data source is the server name, which can be replaced by the server. or (local); initial catalog can replace the name of the database you want to use with the database; Integrated Security = sspi indicates that the integration mode is used. At this time, the UID and PWD settings do not work; the UID and PWD settings take effect only when integrated security = false indicates mixed mode.

The options parameter indicates the commandtext type: adw.text-text command; adcmdtable-table name adw.proc-stored procedure; adcmdunknown-Unknown

5. Add two member functions: (1) execute the query function _ recordsetptr & getrecordset (_ bstr_t bstrsql); (2) execute the SQL statement bool executesql (_ bstr_t bstrsql ).

The complete code of the two files is provided:

/* ---------------- Adoconn. h file -------------------------------------------------*/

// Adoconn. h: interface for the adoconn class.

# Import "C: \ Program Files \ common files \ System \ ADO \ msado15.dll" no_namespace Rename ("EOF", "adoeof") Rename ("Bof", "adobof ")

# If! Defined (afx_adoconn_h1_ac448f02_af26_45e4_9b2d_d7ecb8ffcfb91_encoded _)

# Define afx_adoconn_h1_ac448f02_af26_45e4_9b2d_d7ecb8ffcfb91_encoded _

# If _ msc_ver> 1000

# Pragma once

# Endif // _ msc_ver> 1000

Class adoconn

{

// Define variables

Public:

// Add a pointer to the connection object:

_ Connectionptr m_pconnection;

// Add a pointer to the recordset object:

_ Recordsetptr m_precordset;

// Define the Method

Public:

Adoconn ();

Virtual ~ Adoconn ();

// Initialize-connect to the database

Void oninitadoconn ();

// Execute the query

_ Recordsetptr & getrecordset (_ bstr_t bstrsql );

// Execute the SQL statement, insert update _ variant_t

Bool executesql (_ bstr_t bstrsql );

Void exitconnect ();

};

# Endif //! Defined (afx_adoconn_h1_ac448f02_af26_45e4_9b2d_d7ecb8ffcfb91_encoded _)

/*--------------------------------------------------------------------------------*/

/* --------------------- Adoconn. cpp file ---------------------------*/

# Include "stdafx. H"

# Include "adoconn. H"

# Ifdef _ debug

# UNDEF this_file

Static char this_file [] =__ file __;

# Define new debug_new

# Endif

Adoconn: adoconn ()

{

}

Adoconn ::~ Adoconn ()

{

}

// Initialize-connect to the database

Void adoconn: oninitadoconn ()

{

// Initialize the OLE/COM library Environment

: Coinitialize (null );

Try

{

// Create a connection object

M_pconnection.createinstance ("ADODB. Connection ");

// Set the connection string, which must be of the BSTR or _ bstr_t type

_ Bstr_t strconnect = "provider = sqloledb; server = cz; database = hrsys; uid = sa; Pwd = sa ;";

M_pconnection-> open (strconnect, "", "", admodeunknown );

}

// Catch exceptions

Catch (_ com_error E)

{

// Display the error message

Afxmessagebox (E. Description ());

}

}

// Execute the query

_ Recordsetptr & adoconn: getrecordset (_ bstr_t bstrsql)

{

Try

{

// Connect to the database. If the connection object is null, reconnect to the database.

If (m_pconnection = NULL)

Oninitadoconn ();

// Create a record set object

M_precordset.createinstance (_ uuidof (recordset ));

// Obtain records in the table

M_precordset-> open (bstrsql, m_pconnection.getinterfaceptr (), adopendynamic, adlockoptimistic, adshorttext );

}

// Catch exceptions

Catch (_ com_error E)

{

// Display the error message

Afxmessagebox (E. Description ());

}

// Return record set

Return m_precordset;

}

// Execute the SQL statement, insert update _ variant_t

Bool adoconn: executesql (_ bstr_t bstrsql)

{

// _ Variant_t recordsaffected;

Try

{

// Whether the database has been connected

If (m_pconnection = NULL)

Oninitadoconn ();

// Execute method of the connection object :( _ bstr_t commandtext,

// Variant * recordsaffected, long options)

// Commandtext is a command string, usually an SQL command.

// The recordsaffected parameter indicates the number of rows affected by the operation,

// The options parameter indicates the commandtext type: adcmdtext-text command; adcmdtable-Table Name

// Adw.proc-stored procedure; adcmdunknown-Unknown

M_pconnection-> execute (bstrsql, null, ad1_text );

Return true;

}

Catch (_ com_error E)

{

Afxmessagebox (E. Description ());

Return false;

}

}

Void adoconn: exitconnect ()

{

// Close the record set and Connection

If (m_precordset! = NULL)

M_precordset-> close ();

M_pconnection-> close ();

// Release the environment

: Couninitialize ();

}