Sql express SQL driver connect C++ - c++

Question

Greeting guys , I have been looking on the internet on how to connect C++ code with SQLEXPRESS DATABASE, I have read some threads about how to connect but yet... I CAN NOT follow any of them... neither they are working for me.
I dont want to use MFC or any kind of C++ methods for DB , I want to do it via raw coding.
problem:
the Database connectable via Visual studio and via Microsoft SQL
Server Studio , I can add or drop tables as I LIKE, I believe the DB
as it is, is working fine
the C++ code is here " I am Connecting to a local DB "
I got this code from one of the threads and was not able to figure out how to do the SQLDriverConnect,
I am very noob in C++... adding SQLEXPRESS on top of that...
edit:
I dont know what that 3055 in the connect code is...
thank you in advance for help
Data base information:
UDL:
this what I got from the udl
( Provider=SQLOLEDB.1;Integrated Security=SSPI;
Persist Security Info=False;User ID=sa;Initial Catalog=Holpa;Data Source=AMH )
Microsoft server:
Server type: Database Engine
Server name: AMH
Authen: SQL server Authen
Login: sa
password : amh999
VisualStudio:
Data Source=AMH;Initial Catalog=Holpa;User ID=sa;Password=***********
.NET Framework Data Provider for SQL Server
Open
Microsoft SQL Server
Owner sa
running on local machine.
#include <iostream>
#include <windows.h>
#include <sqltypes.h>
#include <sql.h>
#include <sqlext.h>
using namespace std;
SQLHANDLE sqlenvhandle = SQL_NULL_HANDLE;
SQLHANDLE sqlconnectionhandle = SQL_NULL_HANDLE;
SQLHANDLE sqlstatementhandle = SQL_NULL_HANDLE;
SQLRETURN retcode;
void show_error(RETCODE rc, SQLHENV hEnv, SQLHDBC hDbc,
SQLHSTMT hStmt, const char *action)
{
SQLWCHAR szMessage[256];
SQLWCHAR szState[6];
SDWORD sdwNative;
SWORD swMsgLen;
SQLError(hEnv, hDbc, hStmt, szState, &sdwNative, szMessage,
sizeof(szMessage), &swMsgLen);
wcout << "wcout MESSAGE: " << szMessage << "\n SQLSTATE " << szState << endl;
printf("Error %d performing %s\n SQLState=%s\nSQL message=%s\n",rc, action, szState, szMessage);
}
void CloseSQL()
{
SQLFreeHandle(SQL_HANDLE_STMT, sqlstatementhandle);
SQLDisconnect(sqlconnectionhandle);
SQLFreeHandle(SQL_HANDLE_DBC, sqlconnectionhandle);
SQLFreeHandle(SQL_HANDLE_ENV, sqlenvhandle);
}
int main()
{
if (SQL_SUCCESS != SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &sqlenvhandle))
{
printf("huh \n");
CloseSQL();
goto END;
}
if (SQL_SUCCESS != SQLSetEnvAttr(sqlenvhandle, SQL_ATTR_ODBC_VERSION, (SQLPOINTER)SQL_OV_ODBC3, 0))
{
printf("huh \n");
CloseSQL();
goto END;
}
if (SQL_SUCCESS != SQLAllocHandle(SQL_HANDLE_DBC, sqlenvhandle, &sqlconnectionhandle))
{
printf("huh \n");
CloseSQL();
goto END;
}
printf("Driver Initialised\n");
SQLWCHAR retconstring[1024];
printf("about to Driver Conneect\n");
retcode = SQLDriverConnect(sqlconnectionhandle,
NULL,
(SQLWCHAR*)"DRIVER={SQL Server};SERVER=AMH, 3055;DATABASE=Holpa;UID=sa;PWD=amh999;",
SQL_NTS,
retconstring,
1024,
NULL,
SQL_DRIVER_NOPROMPT);
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO)
{
printf("Connection made\n");
}
else
{
show_error(retcode, sqlenvhandle, sqlconnectionhandle, sqlstatmenthandle, "Connecting.");
}
END:
printf("\n");
printf("Program End, press enter key to exit!");
getchar(); // waits for input
return 0;
}
ERRORS:
the error codes are not constants... they keep changing ... example I got the following:
Message: 0022E1EC
SQLSTATE: 0022e9f4
re-run the program
Message: 009fdc4c
SQLSTATE: 009fe454
rerun the code
Message: 00aadd90
SQLSTATE: 00aae598

Answer 1

Firstly, you need a diagonostic function that works:
void show_error(RETCODE rc, SQLHENV hEnv, SQLHDBC hDbc,
SQLHSTMT hStmt, const char *action)
{
char szMessage[256];
char szState[6];
SDWORD sdwNative;
SWORD swMsgLen;
SQLError(hEnv, hDbc, hStmt, szState, &sdwNative, szMessage,
sizeof(szMessage), &swMsgLen);
printf("Error %d performing %s\n"
"SQLState=%s\nSQL message=%s\n",
rc, action, szState, szMessage);
}
Then call it if anything goes wrong, e.g.:
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO)
{
printf("Connection made\n");
}
else
{
show_error(retcode, sqlenvhandle, sqlconnectionhandle, sqlstatmenthandle, "Connecting.");
}