standard-use-type.cpp

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// Copyright (C) 2004-2006 Maciej Sobczak, Stephen Hutton, David Courtney
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

#define SOCI_ODBC_SOURCE
#include "soci-odbc.h"
#include <cctype>
#include <cstdio>
#include <cstring>
#include <ctime>
#include <sstream>

using namespace soci;
using namespace soci::details;

void odbc_standard_use_type_backend::prepare_for_bind(
    void *&data, SQLLEN &size, SQLSMALLINT &sqlType, SQLSMALLINT &cType)
{
    switch (type_)
    {
    // simple cases
    case x_short:
        sqlType = SQL_SMALLINT;
        cType = SQL_C_SSHORT;
        size = sizeof(short);
        break;
    case x_integer:
        sqlType = SQL_INTEGER;
        cType = SQL_C_SLONG;
        size = sizeof(int);
        break;
    case x_unsigned_long:
        sqlType = SQL_BIGINT;
        cType = SQL_C_ULONG;
        size = sizeof(unsigned long);
        break;
    case x_double:
        sqlType = SQL_DOUBLE;
        cType = SQL_C_DOUBLE;
        size = sizeof(double);
        break;

    // cases that require adjustments and buffer management
    case x_char:
        sqlType = SQL_CHAR;
        cType = SQL_C_CHAR;
        size = sizeof(char)+1;
        buf_ = new char[size];
        data = buf_;
        indHolder_ = SQL_NTS;
        break;
    case x_stdstring:
    {
        // TODO: No textual value is assigned here!

        std::string* s = static_cast<std::string*>(data);
        sqlType = SQL_VARCHAR;
        cType = SQL_C_CHAR;
        size = 255; // !FIXME this is not sufficent
        buf_ = new char[size];
        data = buf_;
        indHolder_ = SQL_NTS;
    }
    break;
    case x_stdtm:
        sqlType = SQL_TIMESTAMP;
        cType = SQL_C_TIMESTAMP;
        buf_ = new char[sizeof(TIMESTAMP_STRUCT)];
        data = buf_;
        size = 19; // This number is not the size in bytes, but the number
                   // of characters in the date if it was written out
                   // yyyy-mm-dd hh:mm:ss
        break;

    case x_blob:
    {
//         sqlType = SQL_VARBINARY;
//         cType = SQL_C_BINARY;

//         BLOB *b = static_cast<BLOB *>(data);

//         odbc_blob_backend *bbe
//         = static_cast<odbc_blob_backend *>(b->getBackEnd());

//         size = 0;
//         indHolder_ = size;
        //TODO            data = &bbe->lobp_;
    }
    break;
    case x_statement:
    case x_rowid:
        break;
    }
}

void odbc_standard_use_type_backend::bind_helper(int &position, void *data, exchange_type type)
{
    data_ = data; // for future reference
    type_ = type; // for future reference

    SQLSMALLINT sqlType;
    SQLSMALLINT cType;
    SQLLEN size;

    prepare_for_bind(data, size, sqlType, cType);

    SQLRETURN rc = SQLBindParameter(statement_.hstmt_,
                                    static_cast<SQLUSMALLINT>(position++),
                                    SQL_PARAM_INPUT,
                                    cType, sqlType, size, 0, data, 0, &indHolder_);

    if (is_odbc_error(rc))
    {
        throw odbc_soci_error(SQL_HANDLE_STMT, statement_.hstmt_,
                                "Binding");
    }
}

void odbc_standard_use_type_backend::bind_by_pos(
    int &position, void *data, exchange_type type, bool /* readOnly */)
{
    if (statement_.boundByName_)
    {
        throw soci_error(
         "Binding for use elements must be either by position or by name.");
    }

    bind_helper(position, data, type);

    statement_.boundByPos_ = true;
}

void odbc_standard_use_type_backend::bind_by_name(
    std::string const &name, void *data, exchange_type type, bool /* readOnly */)
{
    if (statement_.boundByPos_)
    {
        throw soci_error(
         "Binding for use elements must be either by position or by name.");
    }

    int position = -1;
    int count = 1;

    for (std::vector<std::string>::iterator it = statement_.names_.begin();
         it != statement_.names_.end(); ++it)
    {
        if (*it == name)
        {
            position = count;
            break;
        }
        count++;
    }

    if (position != -1)
    {
        bind_helper(position, data, type);
    }
    else
    {
        std::ostringstream ss;
        ss << "Unable to find name '" << name << "' to bind to";
        throw soci_error(ss.str().c_str());
    }

    statement_.boundByName_ = true;
}

void odbc_standard_use_type_backend::pre_use(indicator const *ind)
{
    // first deal with data
    if (type_ == x_char)
    {
        char *c = static_cast<char*>(data_);
        buf_[0] = *c;
        buf_[1] = '\0';
    }
    else if (type_ == x_stdstring)
    {
        std::string *s = static_cast<std::string *>(data_);

        std::size_t const bufSize = 4000;
        std::size_t const sSize = s->size();
        std::size_t const toCopy =
            sSize < bufSize -1 ? sSize + 1 : bufSize - 1;
        strncpy(buf_, s->c_str(), toCopy);
        buf_[toCopy] = '\0';
    }
    else if (type_ == x_stdtm)
    {
        std::tm *t = static_cast<std::tm *>(data_);
        TIMESTAMP_STRUCT * ts = reinterpret_cast<TIMESTAMP_STRUCT*>(buf_);

        ts->year = static_cast<SQLSMALLINT>(t->tm_year + 1900);
        ts->month = static_cast<SQLUSMALLINT>(t->tm_mon + 1);
        ts->day = static_cast<SQLUSMALLINT>(t->tm_mday);
        ts->hour = static_cast<SQLUSMALLINT>(t->tm_hour);
        ts->minute = static_cast<SQLUSMALLINT>(t->tm_min);
        ts->second = static_cast<SQLUSMALLINT>(t->tm_sec);
        ts->fraction = 0;
    }

    // then handle indicators
    if (ind != NULL && *ind == i_null)
    {
        indHolder_ = SQL_NULL_DATA; // null
    }
}

void odbc_standard_use_type_backend::post_use(bool gotData, indicator *ind)
{
    // TODO: Is it possible to have the bound element being overwritten
    // by the database? (looks like yes)
    // If not, then nothing to do here, please remove this comment
    //         and most likely the code below is also unnecessary.
    // If yes, then use the value of the readOnly parameter:
    // - true:  the given object should not be modified and the backend
    //          should detect if the modification was performed on the
    //          isolated buffer and throw an exception if the buffer was modified
    //          (this indicates logic error, because the user used const object
    //          and executed a query that attempted to modified it)
    // - false: the modification should be propagated to the given object (as below).
    //
    // From the code below I conclude that ODBC allows the database to modify the bound object
    // and the code below correctly deals with readOnly == false.
    // The point is that with readOnly == true the propagation of modification should not
    // take place and in addition the attempt of modification should be detected and reported.
    // ...

    // first, deal with data
    if (gotData)
    {
        if (type_ == x_char)
        {
            char *c = static_cast<char*>(data_);
            *c = buf_[0];
        }
        else if (type_ == x_stdstring)
        {
            std::string *s = static_cast<std::string *>(data_);

            *s = buf_;
        }
        else if (type_ == x_stdtm)
        {
            std::tm *t = static_cast<std::tm *>(data_);
            TIMESTAMP_STRUCT * ts = reinterpret_cast<TIMESTAMP_STRUCT*>(buf_);
            t->tm_isdst = -1;
            t->tm_year = ts->year - 1900;
            t->tm_mon = ts->month - 1;
            t->tm_mday = ts->day;
            t->tm_hour = ts->hour;
            t->tm_min = ts->minute;
            t->tm_sec = ts->second;

            // normalize and compute the remaining fields
            std::mktime(t);
        }
    }

    if (ind != NULL)
    {
        if (gotData)
        {
            if (indHolder_ == 0)
            {
                *ind = i_ok;
            }
            else if (indHolder_ == SQL_NULL_DATA)
            {
                *ind = i_null;
            }
            else
            {
                *ind = i_truncated;
            }
        }
    }
}

void odbc_standard_use_type_backend::clean_up()
{
    if (buf_ != NULL)
    {
        delete [] buf_;
        buf_ = NULL;
    }
}