Using ODBC to connect to SQL SERVER 2008

Question

I'm on a W32 machine trying to get a connection with a DB. For that purpose, I tried starting testing an example program:

#include <iostream>
#include <windows.h>
#include <sqltypes.h>
#include <sql.h>
#include <sqlext.h>

using namespace std;

void show_error(unsigned int handletype, const SQLHANDLE& handle){
    SQLCHAR sqlstate[1024];
    SQLCHAR message[1024];
    if(SQL_SUCCESS == SQLGetDiagRec(handletype, handle, 1, sqlstate, NULL, message, 1024, NULL))
        cout<<"Message: "<<message<<"\nSQLSTATE: "<<sqlstate<<endl;
}

int main(){

    SQLHANDLE sqlenvhandle;
    SQLHANDLE sqlconnectionhandle;
    SQLHANDLE sqlstatementhandle;
    SQLRETURN retcode;

    if(SQL_SUCCESS!=SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &sqlenvhandle))
        goto FINISHED;

    if(SQL_SUCCESS!=SQLSetEnvAttr(sqlenvhandle,SQL_ATTR_ODBC_VERSION, (SQLPOINTER)SQL_OV_ODBC3, 0))
        goto FINISHED;

    if(SQL_SUCCESS!=SQLAllocHandle(SQL_HANDLE_DBC, sqlenvhandle, &sqlconnectionhandle))
        goto FINISHED;

    SQLCHAR retconstring[1024];
    switch(SQLDriverConnect (sqlconnectionhandle,
                NULL,
                (SQLCHAR*)"DRIVER={SQL Server};SERVER=localhost, 1433;DATABASE=MyDatabase;UID=sa;PWD=Admin-123;",
                SQL_NTS,
                retconstring,
                1024,
                NULL,
                SQL_DRIVER_NOPROMPT)){
        case SQL_SUCCESS_WITH_INFO:
            show_error(SQL_HANDLE_DBC, sqlconnectionhandle);
            break;
        case SQL_INVALID_HANDLE:
        case SQL_ERROR:
            show_error(SQL_HANDLE_DBC, sqlconnectionhandle);
            goto FINISHED;
        default:
            break;
    }

    if(SQL_SUCCESS!=SQLAllocHandle(SQL_HANDLE_STMT, sqlconnectionhandle, &sqlstatementhandle))
        goto FINISHED;

    if(SQL_SUCCESS!=SQLExecDirect(sqlstatementhandle, (SQLCHAR*)"select * from testtable", SQL_NTS)){
        show_error(SQL_HANDLE_STMT, sqlstatementhandle);
        goto FINISHED;
    }
    else{
        char name[64];
        char address[64];
        int id;
        while(SQLFetch(sqlstatementhandle)==SQL_SUCCESS){
            SQLGetData(sqlstatementhandle, 1, SQL_C_ULONG, &id, 0, NULL);
            SQLGetData(sqlstatementhandle, 2, SQL_C_CHAR, name, 64, NULL);
            SQLGetData(sqlstatementhandle, 3, SQL_C_CHAR, address, 64, NULL);
            cout<<id<<" "<<name<<" "<<address<<endl;
        }
    }

FINISHED:
    SQLFreeHandle(SQL_HANDLE_STMT, sqlstatementhandle );
    SQLDisconnect(sqlconnectionhandle);
    SQLFreeHandle(SQL_HANDLE_DBC, sqlconnectionhandle);
    SQLFreeHandle(SQL_HANDLE_ENV, sqlenvhandle);

}

The problem is that I get MANY problems when trying to compile, regarding undeclared types, for example:

'SQLHANDLE' has not been declared
'SQLHDESC' was not declared in this scope

I've linked to the libodbccpp32.a and libodbc32.a libraries already. What is that I'm doing wrong?

Answer 1

just change include declarations like this:

#include <iostream>
#include <windows.h>
#include <sql.h>
#include <sqltypes.h>
#include <sqlext.h>

Answer 2

I have found with stdafx.h header that the include order should be instead:

#include <iostream>
#include <windows.h>
#include <sqlext.h>
#include <sqltypes.h>
#include <sql.h>

Answer 3

ordering header files does not matter. Just ensure that your project contains in its properties the following include directory:

C:\Program Files (x86)\Microsoft SDKs\Windows\v7.1A\Include

where are found (a priori):

windows.h
sqlext.h
sqltypes.h
sql.h

This suffices in making your commands recognized and compile without any problem.