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Код

#include "stdafx.h"

#include <windows.h>
#include <sqlext.h>


int _tmain(int argc, _TCHAR* argv[])
{
    SQLHENV hSqlEnv = NULL;
    SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hSqlEnv);
    SQLSetEnvAttr(hSqlEnv, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, NULL);

    SQLHDBC hDbc = NULL;
    SQLAllocHandle(SQL_HANDLE_DBC, hSqlEnv, &hDbc);
    LPWSTR lpOutConnectParams = new WCHAR[1024 + 1];
    SHORT i = 0;
    SQLRETURN ODBCcode = SQLDriverConnect(hDbc, NULL, L"Driver=Microsoft Access Driver (*.mdb);DriverId=25;FIL=MS Access;MaxBufferSize=2048;PageTimeout=5;DBQ=db1.mdb", 109, lpOutConnectParams, 1025, &i, SQL_DRIVER_NOPROMPT);
    delete[] lpOutConnectParams;
    if (ODBCcode != SQL_SUCCESS)
    {
        MessageBox(NULL, L"Connect to database failed", L"Error", MB_OK + MB_ICONERROR);
        return 1;
    }

    SQLHSTMT hStmt = NULL;
    SQLAllocStmt(hDbc, &hStmt);
    ODBCcode = SQLExecDirect(hStmt, L"CREATE TABLE TestTable (xKey SMALLINT PRIMARY KEY, xNumericValue INTEGER NOT NULL, xCharValue VARCHAR NOT NULL)", SQL_NTS);
    
    SQLColumns(hStmt, NULL, 0, NULL, 0, (SQLWCHAR*)L"TestTable", SQL_NTS, NULL, 0);
    SQLINTEGER cbColumnName, cbNullable, cbIsNullable;
    SQLSMALLINT Nullable;
    SQLCHAR* lpszColumnName = new SQLCHAR[256 + 1];
    SQLCHAR* lpszIsNullable = new SQLCHAR[256 + 1];
    while (SQLFetch(hStmt) == SQL_SUCCESS)
    {
        cbColumnName = SQL_NTS;
        cbNullable = 0;
        cbIsNullable = SQL_NTS;
        SQLGetData(hStmt, 4, SQL_C_CHAR, lpszColumnName, 256 + 1, &cbColumnName);
        SQLGetData(hStmt, 11, SQL_C_SSHORT, &Nullable, 0, &cbNullable);
        SQLGetData(hStmt, 18, SQL_C_CHAR, lpszIsNullable, 256 + 1, &cbIsNullable);
        if (!Nullable)
            MessageBoxA(NULL, (LPCSTR)lpszColumnName, "This is NOT NULL detected column", MB_OK + MB_ICONINFORMATION);
    }
    delete[] lpszColumnName;
    delete[] lpszIsNullable;

    SQLFreeStmt(hStmt, SQL_CLOSE);
    SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
    SQLDisconnect(hDbc);
    SQLFreeHandle(SQL_HANDLE_DBC, hDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hSqlEnv);
    return 0;
}