bcp_init rturns access violation - c++

Question

I am trying to do bulk copy in sql server using odbc in c++.
here is my code:
#include <stdio.h>
#include <string.h>
#include <windows.h>
#include <sql.h>
#include <sqlext.h>
#include <odbcss.h>
#include<tchar.h>
SQLHENV henv = SQL_NULL_HENV;
HDBC hdbc1 = SQL_NULL_HDBC, hdbc2 = SQL_NULL_HDBC;
SQLHSTMT hstmt2 = SQL_NULL_HSTMT;
void Cleanup() {
if (hstmt2 != SQL_NULL_HSTMT)
SQLFreeHandle(SQL_HANDLE_STMT, hstmt2);
if (hdbc1 != SQL_NULL_HDBC) {
SQLDisconnect(hdbc1);
SQLFreeHandle(SQL_HANDLE_DBC, hdbc1);
}
if (hdbc2 != SQL_NULL_HDBC) {
SQLDisconnect(hdbc2);
SQLFreeHandle(SQL_HANDLE_DBC, hdbc2);
}
if (henv != SQL_NULL_HENV)
SQLFreeHandle(SQL_HANDLE_ENV, henv);
}
void HandleDiagnosticRecord (SQLHANDLE hHandle,
SQLSMALLINT hType,
RETCODE RetCode)
{
SQLSMALLINT iRec = 0;
SQLINTEGER iError;
WCHAR wszMessage[1000];
WCHAR wszState[SQL_SQLSTATE_SIZE+1];
if (RetCode == SQL_INVALID_HANDLE)
{
fwprintf(stderr, L"Invalid handle!\n");
return;
}
while (SQLGetDiagRec(hType,
hHandle,
++iRec,
wszState,
&iError,
wszMessage,
(SQLSMALLINT)(sizeof(wszMessage) / sizeof(WCHAR)),
(SQLSMALLINT *)NULL) == SQL_SUCCESS)
{
// Hide data truncated..
if (wcsncmp(wszState, L"01004", 5))
{
fwprintf(stderr, L"[%5.5s] %s (%d)\n", wszState, wszMessage, iError);
}
}
}
#define TRYODBC(h, ht, x) { RETCODE rc = x;\
if (rc != SQL_SUCCESS) \
{ \
HandleDiagnosticRecord (h, ht, rc); \
} \
if (rc == SQL_ERROR) \
{ \
fwprintf(stderr, L"Error in " L#x L"\n"); \
Sleep(30000); \
} \
}
void extract_error(
char *fn,
SQLHANDLE handle,
SQLSMALLINT type)
{
SQLINTEGER i = 0;
SQLINTEGER native;
SQLWCHAR state[ 7 ];
SQLWCHAR text[256];
SQLSMALLINT len;
SQLRETURN ret;
fprintf(stderr,
"\n"
"The driver reported the following diagnostics whilst running "
"%s\n\n",
fn);
do
{
ret = SQLGetDiagRec(type, handle, ++i, state, &native, text,
sizeof(text), &len );
if (SQL_SUCCEEDED(ret))
printf("%s:%ld:%ld:%s\n", state, i, native, text);
}
while( ret == SQL_SUCCESS );
}
int main() {
RETCODE retcode;
// BCP variables.
char *terminator = "\0";
// bcp_done takes a different format return code because it returns number of rows bulk copied
// after the last bcp_batch call.
DBINT cRowsDone = 0;
// Set up separate return code for bcp_sendrow so it is not using the same retcode as SQLFetch.
RETCODE SendRet;
// Allocate the ODBC environment and save handle.
retcode = SQLAllocHandle (SQL_HANDLE_ENV, NULL, &henv);
if ( (retcode != SQL_SUCCESS_WITH_INFO) && (retcode != SQL_SUCCESS)) {
printf("SQLAllocHandle(Env) Failed\n\n");
Cleanup();
return(9);
}
// Notify ODBC that this is an ODBC 3.0 app.
retcode = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_INTEGER);
if ( (retcode != SQL_SUCCESS_WITH_INFO) && (retcode != SQL_SUCCESS)) {
printf("SQLSetEnvAttr(ODBC version) Failed\n\n");
Cleanup();
return(9);
}
// Allocate ODBC connection handle, set bulk copy mode, and connect.
retcode = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc1);
if ( (retcode != SQL_SUCCESS_WITH_INFO) && (retcode != SQL_SUCCESS)) {
printf("SQLAllocHandle(hdbc1) Failed\n\n");
Cleanup();
return(9);
}
retcode = SQLSetConnectAttr(hdbc1, SQL_COPT_SS_BCP, (void *)SQL_BCP_ON, SQL_IS_INTEGER);
if ( (retcode != SQL_SUCCESS_WITH_INFO) && (retcode != SQL_SUCCESS)) {
printf("SQLSetConnectAttr(hdbc1) Failed\n\n");
Cleanup();
return(9);
}
// sample uses Integrated Security, create the SQL Server DSN using Windows NT authentication
SQLWCHAR dsn[30] = L"mssqltest"; //Name DNS
SQLWCHAR user[10] = L"di_test";
SQLWCHAR pass[10] = L"di_test";
SQLWCHAR tb[20]=L"information1";
retcode = SQLConnectW(hdbc1, (SQLWCHAR *)dsn, SQL_NTS, (SQLWCHAR *) user, SQL_NTS, (SQLWCHAR *) pass, SQL_NTS);
if ( (retcode != SQL_SUCCESS) && (retcode != SQL_SUCCESS_WITH_INFO) ) {
printf("SQLConnect() Failed\n\n");
Cleanup();
return(9);
}
// TRYODBC(hdbc1, SQL_HANDLE_DBC, retcode);
// Initialize the bulk copy.
retcode = bcp_init(hdbc1,L"information1", NULL, NULL, DB_IN);
if ( (retcode != SUCCEED) ) {
printf("bcp_init(hdbc1) Failed\n\n");
Cleanup();
return(9);
}
//Define our array
SQLINTEGER custIDs[] = { 1, 2, 3, 4};
// Bind the program variables for the bulk copy.
retcode = bcp_bind(hdbc1, (BYTE *)custIDs[0], 4, SQL_VARLEN_DATA, NULL, (INT)NULL, SQLINT4, 2);
if ( (retcode != SUCCEED) ) {
printf("bcp_bind(hdbc1) Failed\n\n");
Cleanup();
return(9);
}
// Could normally use strlen to calculate the bcp_bind cbTerm parameter, but this terminator
// is a null byte (\0), which gives strlen a value of 0. Explicitly give cbTerm a value of 1.
retcode = bcp_bind(hdbc1, (BYTE *)custIDs[0], 4, SQL_VARLEN_DATA, NULL, (INT)NULL, SQLINT4, 3);
if ( (retcode != SUCCEED) ) {
printf("bcp_bind(hdbc1) Failed\n\n");
Cleanup();
return(9);
}
if ( (SendRet = bcp_sendrow(hdbc1) ) != SUCCEED ) {
printf("bcp_sendrow(hdbc1) Failed\n\n");
Cleanup();
return(9);
}
cRowsDone = bcp_done(hdbc1);
if ( (cRowsDone == -1) ) {
printf("bcp_done(hdbc1) Failed\n\n");
Cleanup();
return(9);
}
printf("Number of rows bulk copied after last bcp_batch call = %d.\n", cRowsDone);
// Cleanup.
SQLFreeHandle(SQL_HANDLE_STMT, hstmt2);
SQLDisconnect(hdbc1);
SQLFreeHandle(SQL_HANDLE_DBC, hdbc1);
SQLDisconnect(hdbc2);
SQLFreeHandle(SQL_HANDLE_DBC, hdbc2);
SQLFreeHandle(SQL_HANDLE_ENV, henv);
}
in the line:
retcode = bcp_init(hdbc1,L"information1", NULL, NULL, DB_IN);
I get an exception which says, access violation. I recieve no error but an exception.
Does anyone know how should I solve this problem?

Answer 1

I've been using bcp_xxxx functions since 12-15 years in one win32 program. That program was compiled on VS6 and is still on production today.
I recently rewrote the project on VS2015 (finally…). And I had issues with bcp_xxxx functions like you too.
The original VS6 program had these files included:
#include <sql.h>
#include <sqlext.h>
#include "C:\Program Files\Microsoft SQL Server\80\Tools\DevTools\Include\odbcss.h"
SQLDriverConnect() function was used with a connection string containing Driver=SQL Server.
The odbcbcp.lib was added to the linker libraries list. No issues.
The program has been completely revisited for VS2015, changing when appropriate ODBC functions to their version 3.x, and allowing 32 or 64 bit binaries with UNICODE or ANSI charsets.
Recent documentation suggests to use sqlncli.h header and sqlncli11.lib when using bcp_xxxx functions:
#include <sql.h>
#include <sqlext.h>
#define _SQLNCLI_ODBC_
#ifdef _WIN64
#include "C:\Program Files\Microsoft SQL Server\110\SDK\Include\sqlncli.h"
#else
#include "C:\Program Files (x86)\Microsoft SQL Server\110\SDK\Include\sqlncli.h"
#endif
I did it like suggested, and... crash.
I then linked back to odbcbcp.lib, and it works like a charm.
So, I started to search how to use sqlncli11.lib and I found the ODBC connection string should contain Driver=SQL Server Native Client 11.0.
In brief:
- (1) Driver=SQL Server with odbcbcp.lib works
- (2) Driver=SQL Server with sqlncli11.lib makes bcp_init() to crash
- (3) Driver=SQL Server Native Client 11.0 with odbcbcp.lib makes bcp_init() to fail (it returns FAIL=0)
- (4) Driver=SQL Server Native Client 11.0 with sqlncli11.lib works.
Options (1) and (4) are working.
But I found too that using option (4) allows queries to run significantly faster !
So I’ll keep that last one.
Hope this helps.