Started adding support for SELECT statement.
git-svn-id: https://svn.code.sf.net/p/flaim/code/trunk@642 0109f412-320b-0410-ab79-c3e0c5ffbbe6
This commit is contained in:
dsandersoremutah
518
sql/src/select.cpp
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518
sql/src/select.cpp
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@@ -0,0 +1,518 @@
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//------------------------------------------------------------------------------
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// Desc: This module contains the routines for inserting a row into a table.
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//
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// Tabs: 3
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//
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// Copyright (c) 2006 Novell, Inc. All Rights Reserved.
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//
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// This program is free software; you can redistribute it and/or
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// modify it under the terms of version 2 of the GNU General Public
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// License as published by the Free Software Foundation.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, contact Novell, Inc.
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//
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// To contact Novell about this file by physical or electronic mail,
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// you may find current contact information at www.novell.com
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//
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// $Id$
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//------------------------------------------------------------------------------
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#include "flaimsys.h"
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static const char * gv_selectExprTerminators [3] =
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{
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"from",
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",",
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NULL
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};
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static const char * gv_selectWhereTerminators [3] =
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{
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"order",
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NULL
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};
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//------------------------------------------------------------------------------
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// Desc: Process the expressions that are going to be retrieved in a SELECT
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// statement.
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//------------------------------------------------------------------------------
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RCODE SQLStatement::parseSelectExpressions(
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SELECT_EXPR ** ppFirstSelectExpr,
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SELECT_EXPR ** ppLastSelectExpr)
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{
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RCODE rc = NE_SFLM_OK;
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SELECT_EXPR * pSelectExpr;
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SQLQuery * pSqlQuery = NULL;
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const char * pszTerminator;
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// See if they specified "*"
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if (RC_OK( rc = haveToken( "*", FALSE)))
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{
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// Better be followed by "from" - need to consume the "from" token
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// because the caller expects that it will have been consumed.
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rc = haveToken( "from", FALSE, SQL_ERR_EXPECTING_FROM);
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goto Exit;
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}
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else if (rc == NE_SFLM_NOT_FOUND)
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{
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rc = NE_SFLM_OK;
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}
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else
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{
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goto Exit;
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}
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for (;;)
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{
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// Allocate a SELECT_EXPR structure
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if (RC_BAD( rc = m_tmpPool.poolAlloc( sizeof( SELECT_EXPR),
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(void **)&pSelectExpr)))
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{
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goto Exit;
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}
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// Allocate an SQLQuery object, have the pColumnSet structure
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// point to it, and link the pColumnSet structure into the linked
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// list.
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if ((pSqlQuery = f_new SQLQuery) == NULL)
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{
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rc = RC_SET( NE_SFLM_MEM);
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goto Exit;
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}
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pSelectExpr->pSqlQuery = pSqlQuery;
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pSelectExpr->pNext = NULL;
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if (*ppLastSelectExpr)
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{
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(*ppLastSelectExpr)->pNext = pSelectExpr;
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}
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else
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{
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*ppFirstSelectExpr = pSelectExpr;
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}
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*ppLastSelectExpr = pSelectExpr;
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// Now parse the criteria
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if (RC_BAD( rc = parseCriteria( NULL,
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&gv_selectExprTerminators [0], FALSE,
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&pszTerminator, pSqlQuery)))
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{
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goto Exit;
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}
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// Strip out NOT operators, resolve constant arithmetic expressions,
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// and weed out boolean constants, but do not flatten the AND
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// and OR operators in the query tree.
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if (RC_BAD( rc = pSqlQuery->reduceTree( FALSE)))
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{
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goto Exit;
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}
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// Terminator should never be NULL, because we passed a FALSE into
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// parseCriteria for the bEofOK flag.
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flmAssert( pszTerminator);
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// Terminator will have been either be a comma or the FROM keyword.
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if (f_stricmp( pszTerminator, "from") == 0)
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{
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break;
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}
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}
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Exit:
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return( rc);
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}
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//------------------------------------------------------------------------------
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// Desc: Process the SELECT statement. The "SELECT" keyword has already been
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// parsed.
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//------------------------------------------------------------------------------
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RCODE SQLStatement::processSelect( void)
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{
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#define MAX_SELECT_TABLES 15
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RCODE rc = NE_SFLM_OK;
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FLMBOOL bStartedTrans = FALSE;
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char szToken [MAX_SQL_TOKEN_SIZE + 1];
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FLMUINT uiTokenLineOffset;
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FLMUINT uiTokenLen;
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FLMBOOL bDistinct;
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F_TABLE * pTable;
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SELECT_EXPR * pFirstSelectExpr = NULL;
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SELECT_EXPR * pLastSelectExpr = NULL;
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SELECT_EXPR * pSelectExpr;
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SQLQuery sqlQuery;
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TABLE_ITEM tableList [MAX_SELECT_TABLES + 1];
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FLMUINT uiNumTables = 0;
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FLMUINT uiLoop;
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const char * pszTerminator;
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char szName [MAX_SQL_NAME_LEN + 1];
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FLMUINT uiNameLen;
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char szColumnName [MAX_SQL_NAME_LEN + 1];
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FLMUINT uiColumnNameLen;
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FLMUINT uiTableNum;
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FLMUINT uiColumnNum;
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FLMBOOL bDescending;
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SQLParseError eParseError;
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FLMBOOL bHaveWhere = FALSE;
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FLMBOOL bHaveOrderBy = TRUE;
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FLMBOOL bDoneParsingOrderBy;
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// Make sure we have at least a read transaction going.
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if (RC_BAD( rc = m_pDb->checkTransaction( SFLM_READ_TRANS, &bStartedTrans)))
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{
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goto Exit;
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}
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// SYNTAX: SELECT [ALL | DISTINCT] {* | expression [,expression]...}
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// FROM table_name [table_alias] [, table_name [table_alias]]...
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// [WHERE <search_criteria>]
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// [ORDER BY column [ASC | DESC] [, column [ASC | DESC]]...]
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// See if "ALL" or "DISTINCT" were specified
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bDistinct = FALSE;
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if (RC_BAD( rc = getToken( szToken, sizeof( szToken), FALSE,
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&uiTokenLineOffset, NULL)))
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{
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goto Exit;
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}
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if (f_stricmp( szToken, "all") == 0)
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{
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}
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else if (f_stricmp( szToken, "distinct") == 0)
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{
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bDistinct = TRUE;
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}
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else
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{
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// Push the token back into the stream so it will be read again.
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m_uiCurrLineOffset = uiTokenLineOffset;
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}
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// Parse the expressions that are to be selected.
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if (RC_BAD( rc = parseSelectExpressions( &pFirstSelectExpr, &pLastSelectExpr)))
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{
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goto Exit;
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}
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// Get the table names and their aliases.
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for (;;)
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{
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if (RC_BAD( rc = getTableName( TRUE, szName, sizeof( szName),
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&uiNameLen, &pTable)))
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{
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goto Exit;
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}
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// See if we have already defined this table - cannot define it twice.
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for (uiLoop = 0; uiLoop < uiNumTables; uiLoop++)
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{
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if (tableList [uiLoop].uiTableNum == pTable->uiTableNum)
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{
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setErrInfo( m_uiCurrLineNum,
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uiTokenLineOffset,
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SQL_ERR_DUPLICATE_TABLE_NAME,
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m_uiCurrLineFilePos,
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m_uiCurrLineBytes);
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rc = RC_SET( NE_SFLM_INVALID_SQL);
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goto Exit;
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}
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}
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// Must not overflow the name table.
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if (uiNumTables == MAX_SELECT_TABLES)
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{
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setErrInfo( m_uiCurrLineNum,
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m_uiCurrLineOffset - 1,
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SQL_ERR_TOO_MANY_TABLES,
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m_uiCurrLineFilePos,
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m_uiCurrLineBytes);
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rc = RC_SET( NE_SFLM_INVALID_SQL);
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goto Exit;
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}
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// Add the table name to the list
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tableList [uiNumTables].uiTableNum = pTable->uiTableNum;
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tableList [uiNumTables].pszTableAlias = NULL;
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uiNumTables++;
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// See if a table alias was specified, or if we are at a comma or
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// an "ORDER BY" or EOF.
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if (RC_BAD( rc = getToken( szToken, sizeof( szToken), TRUE,
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&uiTokenLineOffset, &uiTokenLen)))
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{
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if (rc == NE_SFLM_EOF_HIT)
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{
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rc = NE_SFLM_OK;
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break;
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}
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goto Exit;
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}
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if (f_stricmp( szToken, "where") == 0)
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{
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bHaveWhere = TRUE;
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break;
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}
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else if (f_stricmp( szToken, "order") == 0)
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{
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bHaveOrderBy = TRUE;
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break;
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}
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else if ((szToken [0] >= 'a' && szToken [0] <= 'z') ||
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(szToken [0] >= 'A' && szToken [0] <= 'Z'))
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{
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// See if this alias name has been used in the table list already.
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for (uiLoop = 0; uiLoop < uiNumTables; uiLoop++)
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{
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if (f_stricmp( tableList [uiLoop].pszTableAlias, szToken) == 0)
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{
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setErrInfo( m_uiCurrLineNum,
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uiTokenLineOffset,
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SQL_ERR_DUPLICATE_ALIAS_NAME,
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m_uiCurrLineFilePos,
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m_uiCurrLineBytes);
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rc = RC_SET( NE_SFLM_INVALID_SQL);
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goto Exit;
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}
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}
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// Set the alias name for our current table. NOTE: Our current
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// table is at element uiNumTables-1, because we have already
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// incremented uiNumTables.
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if (RC_BAD( rc = m_tmpPool.poolAlloc( uiTokenLen + 1,
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(void **)&tableList [uiNumTables - 1].pszTableAlias)))
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{
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goto Exit;
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}
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f_memcpy( &tableList [uiNumTables - 1].pszTableAlias, szToken,
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uiTokenLen + 1);
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}
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else if (f_stricmp( szToken, ",") != 0)
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{
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setErrInfo( m_uiCurrLineNum,
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uiTokenLineOffset,
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SQL_ERR_EXPECTING_COMMA,
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m_uiCurrLineFilePos,
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m_uiCurrLineBytes);
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rc = RC_SET( NE_SFLM_INVALID_SQL);
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goto Exit;
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}
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}
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// parseSelectExpressions will have already parsed the "FROM" keyword.
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// We must now parse table names until we hit a "WHERE" or "ORDER BY" or
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// EOF.
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// Resolve the column names that were parsed in the select expressions.
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tableList [uiNumTables].uiTableNum = 0;
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tableList [uiNumTables].pszTableAlias = NULL;
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for (pSelectExpr = pFirstSelectExpr; pSelectExpr; pSelectExpr = pSelectExpr->pNext)
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{
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if (RC_BAD( rc = pSelectExpr->pSqlQuery->resolveColumnNames( &tableList [0])))
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{
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goto Exit;
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}
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}
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// Add each of the tables in the table list.
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for (uiLoop = 0; uiLoop < uiNumTables; uiLoop++)
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{
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if (RC_BAD( rc = sqlQuery.addTable( tableList [uiLoop].uiTableNum, NULL)))
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{
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goto Exit;
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}
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}
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// If there is a WHERE clause, parse it.
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if (bHaveWhere)
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{
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if (RC_BAD( rc = parseCriteria( &tableList [0],
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&gv_selectWhereTerminators [0], TRUE,
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&pszTerminator, &sqlQuery)))
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{
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goto Exit;
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}
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if (pszTerminator && f_stricmp( pszTerminator, "order") == 0)
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{
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bHaveOrderBy = TRUE;
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}
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}
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// If there is an ORDER BY clause, parse it.
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if (bHaveOrderBy)
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{
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// Make sure we have the "BY" keyword
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if (RC_BAD( rc = haveToken( "by", FALSE, SQL_ERR_EXPECTING_BY)))
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{
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goto Exit;
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}
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for (;;)
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{
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char * pszTableAlias;
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char * pszColumnName;
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// Get either a table name or column name.
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if (RC_BAD( rc = getName( szName, sizeof( szName),
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&uiNameLen, &uiTokenLineOffset)))
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{
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goto Exit;
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}
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// See if we have a period after the name.
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if (RC_BAD( rc = haveToken( ".", TRUE)))
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{
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if (rc != NE_SFLM_NOT_FOUND && rc != NE_SFLM_EOF_HIT)
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{
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goto Exit;
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}
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pszTableAlias = NULL;
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pszColumnName = &szName [0];
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}
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else
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{
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if (RC_BAD( rc = getName( szColumnName, sizeof( szColumnName),
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&uiColumnNameLen, &uiTokenLineOffset)))
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{
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goto Exit;
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}
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pszTableAlias = &szName [0];
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pszColumnName = &szColumnName [0];
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}
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if (RC_BAD( rc = resolveColumnName( m_pDb, &tableList [0], pszTableAlias,
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pszColumnName, &uiTableNum, &uiColumnNum,
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&eParseError)))
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{
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if (eParseError != SQL_NO_ERROR)
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{
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setErrInfo( m_uiCurrLineNum,
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uiTokenLineOffset,
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eParseError,
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m_uiCurrLineFilePos,
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m_uiCurrLineBytes);
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}
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goto Exit;
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}
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// See if the next token is the keyword "ASC" or "DESC" or comma.
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bDoneParsingOrderBy = FALSE;
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bDescending = FALSE;
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if (RC_BAD( rc = getToken( szToken, sizeof( szToken), TRUE,
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&uiTokenLineOffset, &uiTokenLen)))
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{
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if (rc == NE_SFLM_EOF_HIT)
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{
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rc = NE_SFLM_OK;
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bDoneParsingOrderBy = TRUE;
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}
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else
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{
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goto Exit;
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}
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}
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else if (f_stricmp( szToken, "asc") == 0 ||
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f_stricmp( szToken, "desc") == 0)
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{
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if (szToken [0] == 'D' || szToken [0] == 'd')
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{
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bDescending = TRUE;
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}
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if (RC_BAD( rc = getToken( szToken, sizeof( szToken), TRUE,
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&uiTokenLineOffset, &uiTokenLen)))
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{
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if (rc == NE_SFLM_EOF_HIT)
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{
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rc = NE_SFLM_OK;
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bDoneParsingOrderBy = TRUE;
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}
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else
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{
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goto Exit;
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}
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}
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}
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// Add an ORDER BY to the query
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if (RC_BAD( rc = sqlQuery.orderBy( uiTableNum, uiColumnNum, bDescending)))
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{
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goto Exit;
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}
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if (bDoneParsingOrderBy)
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{
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break;
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}
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}
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}
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// Commit the transaction if we started it
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if (bStartedTrans)
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{
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bStartedTrans = FALSE;
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if (RC_BAD( rc = m_pDb->transCommit()))
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{
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goto Exit;
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}
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}
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Exit:
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while (pFirstSelectExpr)
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{
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if (pFirstSelectExpr->pSqlQuery)
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{
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pFirstSelectExpr->pSqlQuery->Release();
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pFirstSelectExpr->pSqlQuery = NULL;
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}
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pFirstSelectExpr = pFirstSelectExpr->pNext;
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}
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if (bStartedTrans)
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{
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m_pDb->transAbort();
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}
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return( rc);
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}
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Block a user