C + + operates on database through ADO

C + + through ADO on database operations

Example: C + + writes data to SQL Server via ADO call stored procedure

1. Import the Microsoft-provided ADO dynamic library into the. h header File

#pragma warning (disable:4146)

#import "C:\\Program Files\\Common Files\\system\\ado\\msado15.dll" Named_guids rename ("EOF", "adoeof"), rename ("BOF" , "Adobof")

#pragma warning (default:4146)

using namespace ADODB;

2. Writing a function call stored procedure

Save Database records

void Savedbtran (char *devid,char * Traceno,char *refno,char *batchno, char * bankcardno, char * trandate, char * trantime, char * Amt,char * Hoscardno,char * Hosname,char * hosidcardno, char *msg)

{

2.1 Creating a database connection handle

_connectionptr Pmyconnect;

HRESULT hr;

Try

{

2.1.1 To build a connection database string

Char *dbconstr = new char[400];

strcpy (Dbconstr, "provider=sqloledb; Server=sqlserver server address, 1433;database= database name, uid= login user; pwd= login password ");

CoInitialize (NULL);

Sleep (300);

2.1.2 handle instantiation to implement a connection

hr = Pmyconnect.createinstance ("ADODB. Connection ");

if (SUCCEEDED (HR))

{

Ct. Savelog ("Create database Connection object successfully, wait for open connection", 0,dbconstr);

Pmyconnect->open (_bstr_t (DBCONSTR), "", "", adModeUnknown);

}

Else

{

CoUninitialize ();

Return

}

}

catch (_com_error &err)

{

CoUninitialize ();

return;

}

2.2 Build Run command parameter handle

_commandptr M_pcommand;

_RecordsetPtr M_precordset;

Try

{

2.2.1 Handle instantiation

M_pcommand.createinstance (__uuidof Command);//command no need to change

M_pcommand->activeconnection = Pmyconnect;//pmyconnect is the connection database handle

M_pcommand->commandtype = Adcmdstoredproc;//adcmdstoredproc without change

M_pcommand->commandtext = _bstr_t ("P_d_tra");//p_d_tra is the name of the stored procedure

2.2.2 Set to variable parameter assignment

_variant_t Vv_dotype,vv_tranno,vv_devid,vv_trandate,vv_trantime;

_variant_t Vv_retcode,vv_bustype,vv_cardno,vv_idcard,vv_name;

_variant_t Vv_amt,vv_notes,vv_serid,vv_descont,vv_tranflag;

_variant_t Vv_bankcardno,vv_bankgroupno,vv_bankflowno,vv_devname,vv_execount;

Value to Variant

Vv_dotype =_variant_t (_bstr_t ("1"));

Vv_tranno =_variant_t (_bstr_t (Temp_traceno));

Vv_devid =_variant_t (_bstr_t (DevID));

Vv_trandate =_variant_t (_bstr_t (datetime));

Vv_trantime =_variant_t (_bstr_t (datetime));

Vv_retcode =_variant_t (_bstr_t (""));

Vv_bustype =_variant_t (_bstr_t ("14"));

Vv_cardno =_variant_t (_bstr_t (Hoscardno));

Vv_idcard =_variant_t (_bstr_t (Hosidcardno));

Vv_name = _variant_t (_bstr_t (hosname));

Vv_amt =_variant_t (_bstr_t (AMT));

Vv_notes =_variant_t (_bstr_t ("Trading Success"));

Vv_serid =_variant_t (_bstr_t (""));

Vv_descont =_variant_t (_bstr_t (""));

Vv_tranflag =_variant_t (_bstr_t ("0"));

Vv_bankcardno =_variant_t (_bstr_t (Temp_bankcardno));

vv_bankgroupno=_variant_t (_bstr_t (Batchno));

Vv_bankflowno =_variant_t (_bstr_t (REFNO));

Vv_devname =_variant_t (_bstr_t (""));

Vv_execount = _variant_t (Ret_execount);

2.2.3 Creating database stored procedure input parameters

_parameterptr Mp_dotype,mp_tranno,mp_devid,mp_trandate,mp_trantime;

_parameterptr Mp_retcode,mp_bustype,mp_cardno,mp_idcard,mp_name;

_parameterptr Mp_amt,mp_notes,mp_serid,mp_descont,mp_tranflag;

_parameterptr Mp_bankcardno,mp_bankgroupno,mp_bankflowno,mp_devname,mp_execount;

2.2.3.1 to instantiate database parameters

Create Parameterptr instance

Mp_dotype. CreateInstance (__uuidof (Parameter));

Mp_tranno.createinstance (__uuidof (Parameter));

Mp_devid.createinstance (__uuidof (Parameter));

Mp_trandate.createinstance (__uuidof (Parameter));

Mp_trantime.createinstance (__uuidof (Parameter));

Mp_retcode.createinstance (__uuidof (Parameter));

Mp_bustype.createinstance (__uuidof (Parameter));

Mp_cardno.createinstance (__uuidof (Parameter));

Mp_idcard.createinstance (__uuidof (Parameter));

Mp_name.createinstance (__uuidof (Parameter));

Mp_amt.createinstance (__uuidof (Parameter));

Mp_notes.createinstance (__uuidof (Parameter));

Mp_serid.createinstance (__uuidof (Parameter));

Mp_descont.createinstance (__uuidof (Parameter));

Mp_tranflag.createinstance (__uuidof (Parameter));

Mp_bankcardno.createinstance (__uuidof (Parameter));

Mp_bankgroupno.createinstance (__uuidof (Parameter));

Mp_bankflowno.createinstance (__uuidof (Parameter));

Mp_devname.createinstance (__uuidof (Parameter));

Mp_execount.createinstance (__uuidof (Parameter));

2.2.3.2 append a database parameter to the end of a parameter property of a command variable handle

Append parameterptr set to _commandptr parameters lists

Database parameter = command variable handle, create parameter method (_bstr_t ("stored procedure parameter name"), stored procedure parameter data type, stored procedure parameter input output type, default size, variable parameter value)

Mp_dotype=m_pcommand->createparameter (_bstr_t ("Dotype"), Adinteger,adparaminput,-1,vv_dotype); //integer type

M_pcommand->parameters->append (Mp_dotype);

Mp_tranno=m_pcommand->createparameter (_bstr_t ("Tranno"), Advarchar,adparaminput,32,vv_tranno); String type

M_pcommand->parameters->append (Mp_tranno);

Mp_devid=m_pcommand->createparameter (_bstr_t ("DevID"), Advarchar,adparaminput,20,vv_devid);

M_pcommand->parameters->append (Mp_devid);

Mp_trandate=m_pcommand->createparameter (_bstr_t ("Trandate"), advarchar,adparaminput,25,vv_trandate);//Time type

M_pcommand->parameters->append (mp_trandate);

Mp_trantime=m_pcommand->createparameter (_bstr_t ("Trantime"), advarchar,adparaminput,25,vv_trantime);

M_pcommand->parameters->append (Mp_trantime);

Mp_retcode=m_pcommand->createparameter (_bstr_t ("RetCode"), Advarchar,adparaminput,20,vv_retcode);

M_pcommand->parameters->append (Mp_retcode);

Mp_bustype=m_pcommand->createparameter (_bstr_t ("BusType"), Adinteger,adparaminput,-1,vv_bustype);

M_pcommand->parameters->append (Mp_bustype);

Mp_cardno=m_pcommand->createparameter (_bstr_t ("Cardno"), Advarchar,adparaminput,20,vv_cardno);

M_pcommand->parameters->append (Mp_cardno);

Mp_idcard=m_pcommand->createparameter (_bstr_t ("Idcard"), Advarchar,adparaminput,20,vv_idcard);

M_pcommand->parameters->append (Mp_idcard);

Mp_name=m_pcommand->createparameter (_bstr_t ("Name"), advarchar,adparaminput,10,vv_name);

M_pcommand->parameters->append (Mp_name);

Mp_amt=m_pcommand->createparameter (_bstr_t ("Amt"), Addecimal,adparaminput,10,vv_amt);//floating-point type

Mp_amt->numericscale = 2; Set the number of digits after the decimal point

Mp_amt->precision = 10; Set the number of integer bits

M_pcommand->parameters->append (Mp_amt);

Mp_notes=m_pcommand->createparameter (_bstr_t ("Notes"), advarchar,adparaminput,2000,vv_notes);

M_pcommand->parameters->append (mp_notes);

Mp_serid=m_pcommand->createparameter (_bstr_t ("Serid"), Advarchar,adparaminput,20,vv_serid);

M_pcommand->parameters->append (Mp_serid);

Mp_descont=m_pcommand->createparameter (_bstr_t ("Descont"), Advarchar,adparaminput,2000,vv_descont);

M_pcommand->parameters->append (Mp_descont);

Mp_tranflag=m_pcommand->createparameter (_bstr_t ("Tranflag"), Adinteger,adparaminput,-1,vv_tranflag);

M_pcommand->parameters->append (Mp_tranflag);

Mp_bankcardno=m_pcommand->createparameter (_bstr_t ("Bankcardno"), Advarchar,adparaminput,25,vv_bankcardno);

M_pcommand->parameters->append (Mp_bankcardno);

Mp_bankgroupno=m_pcommand->createparameter (_bstr_t ("Bankgroupno"), Advarchar,adparaminput,12,vv_bankgroupno) ;

M_pcommand->parameters->append (Mp_bankgroupno);

Mp_bankflowno=m_pcommand->createparameter (_bstr_t ("Bankflowno"), Advarchar,adparaminput,12,vv_bankflowno);

M_pcommand->parameters->append (MP_BANKFLOWNO);

Mp_devname=m_pcommand->createparameter (_bstr_t ("Devname"), advarchar,adparaminput,40,vv_devname);

M_pcommand->parameters->append (Mp_devname);

Mp_execount=m_pcommand->createparameter (_bstr_t ("Execount"), adinteger,adparamoutput,-1,vv_execount);//Output type

M_pcommand->parameters->append (Mp_execount);

2.2.4 execution to get results

_variant_t vnull;

VNULL.VT = Vt_error;

Vnull.scode = Disp_e_paramnotfound;

2.2.4.1 executing a database stored procedure

M_precordset = M_pcommand->execute (&vnull,&vnull,adcmdstoredproc);//adcmdstoredproc do not change

M_precordset Execute SQL Results to determine success, cause of error

if (Mp_execount->value! = 0)

{

Ct. Savelog ("Insert data Failed", 0, "");

}

Else

{

Ct. Savelog ("Insert data Success", 0, "");

}

}

catch (_com_error &err)

{

if (pmyconnect->state) pmyconnect->close ();

Pmyconnect = NULL;

CoUninitialize ();

}

2.2.5 Close Connection Release resources

if (pmyconnect->state) pmyconnect->close ();

Pmyconnect = NULL;

CoUninitialize (); Remember that success or not is called to release resources

return;

}

This article is from the "Poetic Life" blog, please be sure to keep this source http://whish.blog.51cto.com/10679902/1896409

C + + operates on database through ADO