Ask C++ how to connect to SQL server?

//? TestADOSql.cpp？ :? Defines the entry point for the console application.

//

# Contains? " stdafx.h "

# Contains? " iostream "

# Contains? "String"

# Contains? "vector"

//Step 1: Add ADO support.

# Import? “C:\Program？ File \ Public? files \ System \ ado \ msado 15 . dll "？ no_namespace？ Rename ("EOF", "adoEOF")

Use? Namespace? std

int？ _tmain(int？ argc，？ _TCHAR*？ argv[])

{

Co-initialization (null); ? //initialize the COM environment?

_ConnectionPtr？ PMyConnect(__uuidof); //Define the connection object and instantiate the object?

_RecordsetPtr？ pRst(_ _ uuidof(Recordset))； //Define recordset objects and instantiate them?

Try it?

{

//Step 2: Create a data source connection

/* To open the database "SQLServer", you need a database based on your own PC? */?

pmy connect-& gt； open(" Provider = SQL oledb； ? Server =. ; Database = AIS2? uid = sa？ pwd =；" ，""，""，admode unknown)； ?

}?

Catch? (_com_error？ & ampe)？

{?

Cout & lt& lt "initiated? Failure! " & lt& ltendl？

cout & lt& lte . Description()& lt； & ltendl？

cout & lt& lte . HelpFile()& lt； & ltendl？

Return? 0; ?

}?

Cout & lt& lt "connection? Success! " & lt& ltendl？

//Step 3: Operate the database/table in the data source.

Try it?

{

pRst？ =? pmy connect-& gt； Execute ("Select? *? From where? gendat "，NULL，ADC mdtext)； //execute SQL:? Choice? *? From where? Gendat

If (! pRst-& gt； BOF)？

{

pRst-& gt； MoveFirst()； ?

}?

other

{

Cout < < "data? Is it? Empty! " & lt& ltendl？

Return? 0;

}?

Vector & lt_ bstr _ t>? column _ name

/* Store all the column names of the table and display the column names of the table */?

for(int？ I = 0； ? I<? pRst-& gt； Field-> GetCount()； i++)？

{

cout & lt& ltpRst-& gt； Field-> GetItem(_ variant _ t((long)I))-& gt； Name & lt& lt "?" ;

column _ name . push _ back(pRst-& gt； Field-> GetItem(_ variant _ t((long)I))-& gt； Name); ?

}?

cout & lt& ltendl

/* Traverse the table and display the contents of each row in the table */?

And (! pRst-& gt； adoEOF)？

{

Vector & lt_ bstr _ t>* iterator? ITER = column _ name . begin()；

for(ITER； iter！ = column _ name . end()； iter++)

{?

if(pRst-& gt； GetCollect(*iter)。 vt？ ! =VT_NULL)？

{

cout & lt& lt(_ bstr _ t)pRst-& gt； get collect(* ITER)& lt； & lt"?" ; ?

}?

other

{

cout & lt& lt" NULL " & lt& ltendl

}

}

pRst-& gt； MoveNext()； ?

cout & lt& ltendl

}?

}

catch(_com_error？ & ampe)？

{?

cout & lt& lte . Description()& lt； & ltendl？

cout & lt& lte . HelpFile()& lt； & ltendl？

Return? 0;

}

//Step 4: Close the data source.

/* Close the database and release the pointer */

Try it?

{?

pRst-& gt； close()； ? //Close the recordset?

pmy connect-& gt； close()； //Close the database?

pRst。 Publish (); //Release the recordset object pointer?

pMyConnect。 Publish (); //Release the connection object pointer

}

catch(_com_error？ & ampe)？

{?

cout & lt& lte . Description()& lt； & ltendl？

cout & lt& lte . HelpFile()& lt； & ltendl？

Return? 0; ?

}

coun initialize()； ? //publish COM environment

Return? 0;

}