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<?php
/* vim: set expandtab tabstop=4 shiftwidth=4: */
// +----------------------------------------------------------------------+
// | Copyright (c) 2003-2004 John Griffin |
// +----------------------------------------------------------------------+
// | This library is free software; you can redistribute it and/or |
// | modify it under the terms of the GNU Lesser General Public |
// | License as published by the Free Software Foundation; either |
// | version 2.1 of the License, or (at your option) any later version. |
// | |
// | This library is distributed in the hope that it will be useful, |
// | but WITHOUT ANY WARRANTY; without even the implied warranty of |
// | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
// | Lesser General Public License for more details. |
// | |
// | You should have received a copy of the GNU Lesser General Public |
// | License along with this library; if not, write to the Free Software |
// | Foundation, Inc., 59 Temple Place, Suite 330,Boston,MA 02111-1307 USA|
// +----------------------------------------------------------------------+
// | Authors: John Griffin <jgriffin316@netscape.net> |
// +----------------------------------------------------------------------+
//
// $Id: Compiler.php,v 1.1 2004/05/07 12:33:35 busterb Exp $
//
require_once 'PEAR.php';
/**
* A SQL parse tree compiler.
*
* @author John Griffin <jgriffin316@netscape.net>
* @version 0.1
* @access public
* @package SQL_Parser
*/
class SQL_Compiler {
var $tree;
// {{{ function SQL_Compiler($array = null)
function SQL_Compiler($array = null)
{
$this->tree = $array;
}
// }}}
// {{{ function getWhereValue ($arg)
function getWhereValue ($arg)
{
switch ($arg['type']) {
case 'ident':
case 'real_val':
case 'int_val':
$value = $arg['value'];
break;
case 'text_val':
$value = '\''.$arg['value'].'\'';
break;
case 'subclause':
$value = '('.$this->compileSearchClause($arg['value']).')';
break;
default:
return PEAR::raiseError('Unknown type: '.$arg['type']);
}
return $value;
}
// }}}
// {{{ function getParams($arg)
function getParams($arg)
{
for ($i = 0; $i < sizeof ($arg['type']); $i++) {
switch ($arg['type'][$i]) {
case 'ident':
case 'real_val':
case 'int_val':
$value[] = $arg['value'][$i];
break;
case 'text_val':
$value[] = '\''.$arg['value'][$i].'\'';
break;
default:
return PEAR::raiseError('Unknown type: '.$arg['type']);
}
}
$value ='('.implode(', ', $value).')';
return $value;
}
// }}}
// {{{ function compileSearchClause
function compileSearchClause($where_clause)
{
$value = '';
if (isset ($where_clause['arg_1']['value'])) {
$value = $this->getWhereValue ($where_clause['arg_1']);
if (PEAR::isError($value)) {
return $value;
}
$sql = $value;
} else {
$value = $this->compileSearchClause($where_clause['arg_1']);
if (PEAR::isError($value)) {
return $value;
}
$sql = $value;
}
if (isset ($where_clause['op'])) {
if ($where_clause['op'] == 'in') {
$value = $this->getParams($where_clause['arg_2']);
if (PEAR::isError($value)) {
return $value;
}
$sql .= ' '.$where_clause['op'].' '.$value;
} elseif ($where_clause['op'] == 'is') {
if (isset ($where_clause['neg'])) {
$value = 'not null';
} else {
$value = 'null';
}
$sql .= ' is '.$value;
} else {
$sql .= ' '.$where_clause['op'].' ';
if (isset ($where_clause['arg_2']['value'])) {
$value = $this->getWhereValue ($where_clause['arg_2']);
if (PEAR::isError($value)) {
return $value;
}
$sql .= $value;
} else {
$value = $this->compileSearchClause($where_clause['arg_2']);
if (PEAR::isError($value)) {
return $value;
}
$sql .= $value;
}
}
}
return $sql;
}
// }}}
// {{{ function compileSelect()
function compileSelect()
{
// save the command and set quantifiers
$sql = 'select ';
if (isset($this->tree['set_quantifier'])) {
$sql .= $this->tree['set_quantifier'].' ';
}
// save the column names and set functions
for ($i = 0; $i < sizeof ($this->tree['column_names']); $i++) {
$column = $this->tree['column_names'][$i];
if ($this->tree['column_aliases'][$i] != '') {
$column .= ' as '.$this->tree['column_aliases'][$i];
}
$column_names[] = $column;
}
for ($i = 0; $i < sizeof ($this->tree['set_function']); $i++) {
$column = $this->tree['set_function'][$i]['name'].'(';
if (isset ($this->tree['set_function'][$i]['distinct'])) {
$column .= 'distinct ';
}
if (isset ($this->tree['set_function'][$i]['arg'])) {
$column .= implode (',', $this->tree['set_function'][$i]['arg']);
}
$column .= ')';
if ($this->tree['set_function'][$i]['alias'] != '') {
$column .= ' as '.$this->tree['set_function'][$i]['alias'];
}
$column_names[] = $column;
}
if (isset($column_names)) {
$sql .= implode (", ", $column_names);
}
// save the tables
$sql .= ' from ';
for ($i = 0; $i < sizeof ($this->tree['table_names']); $i++) {
$sql .= $this->tree['table_names'][$i];
if ($this->tree['table_aliases'][$i] != '') {
$sql .= ' as '.$this->tree['table_aliases'][$i];
}
if ($this->tree['table_join_clause'][$i] != '') {
$search_string = $this->compileSearchClause ($this->tree['table_join_clause'][$i]);
if (PEAR::isError($search_string)) {
return $search_string;
}
$sql .= ' on '.$search_string;
}
if (isset($this->tree['table_join'][$i])) {
$sql .= ' '.$this->tree['table_join'][$i].' ';
}
}
// save the where clause
if (isset($this->tree['where_clause'])) {
$search_string = $this->compileSearchClause ($this->tree['where_clause']);
if (PEAR::isError($search_string)) {
return $search_string;
}
$sql .= ' where '.$search_string;
}
// save the group by clause
if (isset ($this->tree['group_by'])) {
$sql .= ' group by '.implode(', ', $this->tree['group_by']);
}
// save the order by clause
if (isset ($this->tree['sort_order'])) {
foreach ($this->tree['sort_order'] as $key => $value) {
$sort_order[] = $key.' '.$value;
}
$sql .= ' order by '.implode(', ', $sort_order);
}
// save the limit clause
if (isset ($this->tree['limit_clause'])) {
$sql .= ' limit '.$this->tree['limit_clause']['start'].','.$this->tree['limit_clause']['length'];
}
return $sql;
}
// }}}
// {{{ function compileUpdate()
function compileUpdate()
{
$sql = 'update '.implode(', ', $this->tree['table_names']);
// save the set clause
for ($i = 0; $i < sizeof ($this->tree['column_names']); $i++) {
$set_columns[] = $this->tree['column_names'][$i].' = '.$this->getWhereValue($this->tree['values'][$i]);
}
$sql .= ' set '.implode (', ', $set_columns);
// save the where clause
if (isset($this->tree['where_clause'])) {
$search_string = $this->compileSearchClause ($this->tree['where_clause']);
if (PEAR::isError($search_string)) {
return $search_string;
}
$sql .= ' where '.$search_string;
}
return $sql;
}
// }}}
// {{{ function compileDelete()
function compileDelete()
{
$sql = 'delete from '.implode(', ', $this->tree['table_names']);
// save the where clause
if (isset($this->tree['where_clause'])) {
$search_string = $this->compileSearchClause ($this->tree['where_clause']);
if (PEAR::isError($search_string)) {
return $search_string;
}
$sql .= ' where '.$search_string;
}
return $sql;
}
// }}}
// {{{ function compileInsert()
function compileInsert()
{
$sql = 'insert into '.$this->tree['table_names'][0].' ('.
implode(', ', $this->tree['column_names']).') values (';
for ($i = 0; $i < sizeof ($this->tree['values']); $i++) {
$value = $this->getWhereValue ($this->tree['values'][$i]);
if (PEAR::isError($value)) {
return $value;
}
$value_array[] = $value;
}
$sql .= implode(', ', $value_array).')';
return $sql;
}
// }}}
// {{{ function compile($array = null)
function compile($array = null)
{
$this->tree = $array;
switch ($this->tree['command']) {
case 'select':
return $this->compileSelect();
break;
case 'update':
return $this->compileUpdate();
break;
case 'delete':
return $this->compileDelete();
break;
case 'insert':
return $this->compileInsert();
break;
case 'create':
case 'drop':
case 'modify':
default:
return PEAR::raiseError('Unknown action: '.$this->tree['command']);
} // switch ($this->_tree["command"])
}
// }}}
}
?>
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