<?php

/**

* OracleSQLTranslator

*

* A translator from MySQL dialect into Oracle dialect for Limesurvey

* (http://www.limesurvey.org/)

*

* Copyright (c) 2012, André Rothe <[email protected], [email protected]>

*

* All rights reserved.

*

* Redistribution and use in source and binary forms, with or without modification,

* are permitted provided that the following conditions are met:

*

* * Redistributions of source code must retain the above copyright notice,

* this list of conditions and the following disclaimer.

* * Redistributions in binary form must reproduce the above copyright notice,

* this list of conditions and the following disclaimer in the documentation

* and/or other materials provided with the distribution.

*

* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY

* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT

* SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,

* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED

* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR

* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH

* DAMAGE.

*/

require_once('php-sql-parser.php');

require_once('php-sql-creator.php');

include_once($rootdir . '/classes/adodb/adodb.inc.php');

$_ENV['DEBUG'] = 1;

class OracleSQLTranslator extends PHPSQLCreator {

private $con; # this is the database connection from LimeSurvey

private $preventColumnRefs = array();

private $allTables = array();

const ASTERISK_ALIAS = "[#RePl#]";

public function __construct($con) {

parent::__construct();

$this->con = $con;

$this->initGlobalVariables();

}

private function initGlobalVariables() {

$this->preventColumnRefs = false;

$this->allTables = array();

}

public static function dbgprint($txt) {

if (isset($_ENV['DEBUG'])) {

print $txt;

}

}

public static function preprint($s, $return = false) {

$x = "<pre>";

$x .= print_r($s, 1);

$x .= "</pre>";

if ($return) {

return $x;

}

self::dbgprint($x . "<br/>\n");

}

protected function processAlias($parsed) {

if ($parsed === false) {

return "";

}

# we don't need an AS between expression and alias

$sql = " " . $parsed['name'];

return $sql;

}

protected function processDELETE($parsed) {

if (count($parsed['TABLES']) > 1) {

die("cannot translate delete statement into Oracle dialect, multiple tables are not allowed.");

}

return "DELETE";

}

public static function getColumnNameFor($column) {

if (strtolower($column) === 'uid') {

$column = "uid_";

}

// TODO: add more here, if necessary

return $column;

}

public static function getShortTableNameFor($table) {

if (strtolower($table) === 'surveys_languagesettings') {

$table = 'surveys_lngsettings';

}

// TODO: add more here, if necessary

return $table;

}

protected function processTable($parsed, $index) {

if ($parsed['expr_type'] !== 'table') {

return "";

}

$sql = $this->getShortTableNameFor($parsed['table']);

$alias = $this->processAlias($parsed['alias']);

$sql .= $alias;

if ($index !== 0) {

$sql = $this->processJoin($parsed['join_type']) . " " . $sql;

$sql .= $this->processRefType($parsed['ref_type']);

$sql .= $this->processRefClause($parsed['ref_clause']);

}

# store the table and its alias for later use

$last = array_pop($this->allTables);

$last['tables'][] = array('table' => $this->getShortTableNameFor($parsed['table']), 'alias' => trim($alias));

$this->allTables[] = $last;

return $sql;

}

protected function processFROM($parsed) {

$this->allTables[] = array('tables' => array(), 'alias' => '');

return parent::processFROM($parsed);

}

protected function processTableExpression($parsed, $index) {

if ($parsed['expr_type'] !== 'table_expression') {

return "";

}

$sql = substr($this->processFROM($parsed['sub_tree']), 5); // remove FROM keyword

$sql = "(" . $sql . ")";

$alias .= $this->processAlias($parsed['alias']);

$sql .= $alias;

# store the tables-expression-alias for later use

$last = array_pop($this->allTables);

$last['alias'] = trim($alias);

$this->allTables[] = $last;

if ($index !== 0) {

$sql = $this->processJoin($parsed['join_type']) . " " . $sql;

$sql .= $this->processRefType($parsed['ref_type']);

$sql .= $this->processRefClause($parsed['ref_clause']);

}

return $sql;

}

private function getTableNameFromExpression($expr) {

$pos = strpos($expr, ".");

if ($pos === false) {

$pos = -1;

}

return trim(substr($expr, 0, $pos + 1), ".");

}

private function getColumnNameFromExpression($expr) {

$pos = strpos($expr, ".");

if ($pos === false) {

$pos = -1;

}

return substr($expr, $pos + 1);

}

private function isCLOBColumnInDB($table, $column) {

$res = $this->con->GetOne(

"SELECT count(*) FROM user_lobs WHERE table_name='" . strtoupper($table) . "' AND column_name='"

. strtoupper($column) . "'");

return ($res >= 1);

}

protected function isCLOBColumn($table, $column) {

$tables = end($this->allTables);

if ($table === "") {

foreach ($tables['tables'] as $k => $v) {

if ($this->isCLOBColumn($v['table'], $column)) {

return true;

}

}

return false;

}

# check the aliases, $table cannot be empty

foreach ($tables['tables'] as $k => $v) {

if ((strtolower($v['alias']) === strtolower($table))

|| (strtolower($tables['alias']) === strtolower($table))) {

if ($this->isCLOBColumnInDB($v['table'], $column)) {

return true;

}

}

}

# it must be a valid table name

return $this->isCLOBColumnInDB($table, $column);

}

protected function processOrderByExpression($parsed) {

if ($parsed['type'] !== 'expression') {

return "";

}

$table = $this->getTableNameFromExpression($parsed['base_expr']);

$col = $this->getColumnNameFromExpression($parsed['base_expr']);

$sql = ($table !== "" ? $table . "." : "") . $col;

# check, if the column is a CLOB

if ($this->isCLOBColumn($table, $col)) {

$sql = "cast(substr(" . $sql . ",1,200) as varchar2(200))";

}

return $sql . " " . $parsed['direction'];

}

protected function processColRef($parsed) {

if ($parsed['expr_type'] !== 'colref') {

return "";

}

$table = $this->getTableNameFromExpression($parsed['base_expr']);

$col = $this->getColumnNameFromexpression($parsed['base_expr']);

# we have to change the column name, if the column is uid

# we have to change the tablereference, if the tablename is too long

$col = $this->getColumnNameFor($col);

$table = $this->getShortTableNameFor($table);

# if we have * as colref, we cannot use other columns

# we have to add alias.* if we know all table aliases

if (($table === "") && ($col === "*")) {

array_pop($this->preventColumnRefs);

$this->preventColumnRefs[] = true;

return ASTERISK_ALIAS; # this is the position, we have to replace later

}

$alias = "";

if (isset($parsed['alias'])) {

$alias = $this->processAlias($parsed['alias']);

}

return (($table !== "") ? ($table . "." . $col) : $col) . $alias;

}

protected function processFunctionOnSelect($parsed) {

$old = end($this->preventColumnRefs);

$sql = $this->processFunction($parsed);

if ($old !== end($this->preventColumnRefs)) {

# prevents wrong handling of count(*)

array_pop($this->preventColumnRefs);

$this->preventColumnRefs[] = $old;

$sql = str_replace(ASTERISK_ALIAS, "*", $sql);

}

return $sql;

}

protected function processSELECT($parsed) {

$this->preventColumnRefs[] = false;

$sql = "";

foreach ($parsed as $k => $v) {

$len = strlen($sql);

$sql .= $this->processColRef($v);

$sql .= $this->processSelectExpression($v);

$sql .= $this->processFunctionOnSelect($v);

$sql .= $this->processConstant($v);

if ($len == strlen($sql)) {

$this->stop('SELECT', $k, $v, 'expr_type');

}

$sql .= ",";

}

$sql = substr($sql, 0, -1);

return "SELECT " . $sql;

}

private function correctColRefStatement($sql) {

$alias = "";

$tables = end($this->allTables);

# should we correct the selection list?

if (array_pop($this->preventColumnRefs)) {

# do we have a table-expression alias?

if ($tables['alias'] !== "") {

$alias = $tables['alias'] . ".*";

} else {

foreach ($tables['tables'] as $k => $v) {

$alias .= ($v['alias'] === "" ? $v['table'] : $v['alias']) . ".*,";

}

$alias = substr($alias, 0, -1);

}

$sql = str_replace(ASTERISK_ALIAS, $alias, $sql);

}

return $sql;

}

protected function processSelectStatement($parsed) {

$sql = $this->processSELECT($parsed['SELECT']);

$from = $this->processFROM($parsed['FROM']);

# correct * references with tablealias.*

# this must be called after processFROM(), because we need the table information

$sql = $this->correctColRefStatement($sql) . " " . $from;

if (isset($parsed['WHERE'])) {

$sql .= " " . $this->processWHERE($parsed['WHERE']);

}

if (isset($parsed['GROUP'])) {

$sql .= " " . $this->processGROUP($parsed['GROUP']);

}

if (isset($parsed['ORDER'])) {

$sql .= " " . $this->processORDER($parsed['ORDER']);

}

# select finished, we remove its tables

# FIXME: we should add it to the previous tablelist with the

# global alias, if such one exists

array_pop($this->allTables);

return $sql;

}

public function create($parsed) {

$k = key($parsed);

switch ($k) {

case "USE":

# this statement is not an Oracle statement

$this->created = "";

break;

default:

$this->created = parent::create($parsed);

break;

}

return $this->created;

}

public function process($sql) {

self::dbgprint($sql . "<br/>");

$this->initGlobalVariables();

$parser = new PHPSQLParser($sql);

self::preprint($parser->parsed);

$sql = $this->create($parser->parsed);

self::dbgprint($sql . "<br/>");

return $sql;

}

}

//$translator = new OracleSQLTranslator(false);

//$translator->process("SELECT q.qid, question, gid FROM questions as q WHERE (select count(*) from answers as a where a.qid=q.qid and scale_id=0)=0 and sid=11929 AND type IN ('F', 'H', 'W', 'Z', '1') and q.parent_qid=0");

//$translator->process("SELECT *, (SELECT a from xyz WHERE b>1) haha, (SELECT *, b from zks,abc WHERE d=1) hoho FROM blubb d, blibb c WHERE d.col = c.col");