cursor.cpp

ncbi源码

/*
 * ===========================================================================
 * PRODUCTION $Log: cursor.cpp,v $
 * PRODUCTION Revision 1000.1  2004/06/01 19:20:49  gouriano
 * PRODUCTION PRODUCTION: UPGRADED [GCC34_MSVC7] Dev-tree R1.11
 * PRODUCTION
 * ===========================================================================
 */

/* $Id: cursor.cpp,v 1000.1 2004/06/01 19:20:49 gouriano Exp $
 * ===========================================================================
 *
 *                            PUBLIC DOMAIN NOTICE
 *               National Center for Biotechnology Information
 *
 *  This software/database is a "United States Government Work" under the
 *  terms of the United States Copyright Act.  It was written as part of
 *  the author's official duties as a United States Government employee and
 *  thus cannot be copyrighted.  This software/database is freely available
 *  to the public for use. The National Library of Medicine and the U.S.
 *  Government have not placed any restriction on its use or reproduction.
 *
 *  Although all reasonable efforts have been taken to ensure the accuracy
 *  and reliability of the software and data, the NLM and the U.S.
 *  Government do not and cannot warrant the performance or results that
 *  may be obtained by using this software or data. The NLM and the U.S.
 *  Government disclaim all warranties, express or implied, including
 *  warranties of performance, merchantability or fitness for any particular
 *  purpose.
 *
 *  Please cite the author in any work or product based on this material.
 *
 * ===========================================================================
 *
 * Author:  Vladimir Soussov
 *
 * File Description:  TDS cursor command
 *
 */

#include <ncbi_pch.hpp>
#include <dbapi/driver/ftds/interfaces.hpp>


BEGIN_NCBI_SCOPE


/////////////////////////////////////////////////////////////////////////////
//
//  CTDS_CursorCmd::
//

CTDS_CursorCmd::CTDS_CursorCmd(CTDS_Connection* con, DBPROCESS* cmd,
                               const string& cursor_name, const string& query,
                               unsigned int nof_params) :
    m_Connect(con), m_Cmd(cmd), m_Name(cursor_name), m_LCmd(0), m_Query(query),
    m_Params(nof_params), m_IsOpen(false), m_HasFailed(false),
    m_IsDeclared(false), m_Res(0), m_RowCount(-1)
{
}


bool CTDS_CursorCmd::BindParam(const string& param_name, CDB_Object* param_ptr)
{
    return
        m_Params.BindParam(CDB_Params::kNoParamNumber, param_name, param_ptr);
}

static bool for_update_of(const string& q)
{
    if((q.find("update") == string::npos) && 
       (q.find("UPDATE") == string::npos))
        return false;

    if((q.find("for update") != string::npos) || 
       (q.find("FOR UPDATE") != string::npos)) 
        return true;

    // TODO: add more logic here to find "for update" clause
    return false;
}

CDB_Result* CTDS_CursorCmd::Open()
{
    if (m_IsOpen) { // need to close it first
        Close();
    }

    m_HasFailed = false;

    // declare the cursor
    if (!x_AssignParams()) {
        m_HasFailed = true;
        throw CDB_ClientEx(eDB_Error, 222003, "CTDS_CursorCmd::Open",
                           "cannot assign params");
    }


    m_LCmd = 0;
    string cur_feat;
    if(for_update_of(m_Query)) {
        cur_feat= " cursor FORWARD_ONLY SCROLL_LOCKS for ";
    }
    else {
        cur_feat= " cursor FORWARD_ONLY for ";
    }
        
    string buff = "declare " + m_Name + cur_feat + m_Query;

    try {
        m_LCmd = m_Connect->LangCmd(buff);
        m_LCmd->Send();
        m_LCmd->DumpResults();
#if 0
        while (m_LCmd->HasMoreResults()) {
            CDB_Result* r = m_LCmd->Result();
            if (r) {
                while (r->Fetch())
                    ;
                delete r;
            }
        }
#endif
        delete m_LCmd;
    } catch (CDB_Exception& e) {
        if (m_LCmd) {
            delete m_LCmd;
            m_LCmd = 0;
        }
        throw CDB_ClientEx(eDB_Error, 222001, "CTDS_CursorCmd::Open",
                           "failed to declare cursor");
    }
    m_IsDeclared = true;

    // open the cursor
    m_LCmd = 0;
    buff = "open " + m_Name;

    try {
        m_LCmd = m_Connect->LangCmd(buff);
        m_LCmd->Send();
        m_LCmd->DumpResults();
#if 0
        while (m_LCmd->HasMoreResults()) {
            CDB_Result* r = m_LCmd->Result();
            if (r) {
                while (r->Fetch())
                    ;
                delete r;
            }
        }
#endif
        delete m_LCmd;
    } catch (CDB_Exception& e) {
        if (m_LCmd) {
            delete m_LCmd;
            m_LCmd = 0;
        }
        throw CDB_ClientEx(eDB_Error, 222002, "CTDS_CursorCmd::Open",
                           "failed to open cursor");
    }
    m_IsOpen = true;

    m_LCmd = 0;
    buff = "fetch " + m_Name;

    m_LCmd = m_Connect->LangCmd(buff);
    m_Res = new CTDS_CursorResult(m_LCmd);
    return Create_Result(*m_Res);
}


bool CTDS_CursorCmd::Update(const string&, const string& upd_query)
{
    if (!m_IsOpen)
        return false;

    CDB_LangCmd* cmd = 0;

    try {
	while(m_LCmd->HasMoreResults()) {
	    CDB_Result* r= m_LCmd->Result();
	    if(r) delete r;
	}

        string buff = upd_query + " where current of " + m_Name;
        cmd = m_Connect->LangCmd(buff);
        cmd->Send();
        cmd->DumpResults();
#if 0
        while (cmd->HasMoreResults()) {
            CDB_Result* r = cmd->Result();
            if (r) {
                while (r->Fetch())
                    ;
                delete r;
            }
        }
#endif
        delete cmd;
    } catch (CDB_Exception& e) {
        if (cmd)
            delete cmd;
        throw CDB_ClientEx(eDB_Error, 222004, "CTDS_CursorCmd::Update",
                           "update failed");
    }

    return true;
}

I_ITDescriptor* CTDS_CursorCmd::x_GetITDescriptor(unsigned int item_num)
{
    if(!m_IsOpen || (m_Res == 0)) {
        return 0;
    }
    while(m_Res->CurrentItemNo() < item_num) {
        if(!m_Res->SkipItem()) return 0;
    }
    
    I_ITDescriptor* desc= new CTDS_ITDescriptor(m_Cmd, item_num+1);
    return desc;
}

bool CTDS_CursorCmd::UpdateTextImage(unsigned int item_num, CDB_Stream& data, 
				    bool log_it)
{
    I_ITDescriptor* desc= x_GetITDescriptor(item_num);
    C_ITDescriptorGuard d_guard(desc);

    if(desc) {
        while(m_LCmd->HasMoreResults()) {
            CDB_Result* r= m_LCmd->Result();
            if(r) delete r;
        }
        
        return m_Connect->x_SendData(*desc, data, log_it);
    }
    return false;
}

CDB_SendDataCmd* CTDS_CursorCmd::SendDataCmd(unsigned int item_num, size_t size, 
					    bool log_it)
{
    I_ITDescriptor* desc= x_GetITDescriptor(item_num);
    C_ITDescriptorGuard d_guard(desc);

    if(desc) {
        m_LCmd->DumpResults();
#if 0
        while(m_LCmd->HasMoreResults()) {
            CDB_Result* r= m_LCmd->Result();
            if(r) delete r;
        }
#endif
        
        return m_Connect->SendDataCmd(*desc, size, log_it);
    }
    return 0;
}					    

bool CTDS_CursorCmd::Delete(const string& table_name)
{
    if (!m_IsOpen)
        return false;

    CDB_LangCmd* cmd = 0;

    try {
	while(m_LCmd->HasMoreResults()) {
	    CDB_Result* r= m_LCmd->Result();
	    if(r) delete r;
	}

        string buff = "delete " + table_name + " where current of " + m_Name;
        cmd = m_Connect->LangCmd(buff);
        cmd->Send();
        cmd->DumpResults();
#if 0
        while (cmd->HasMoreResults()) {
            CDB_Result* r = cmd->Result();
            if (r) {
                while (r->Fetch())
                    ;
                delete r;
            }
        }
#endif
        delete cmd;
    } catch (CDB_Exception& e) {
        if (cmd)
            delete cmd;
        throw CDB_ClientEx(eDB_Error, 222004, "CTDS_CursorCmd::Update",
                           "update failed");
    }

    return true;
}


int CTDS_CursorCmd::RowCount() const
{
    return m_RowCount;
}