scc_pg_admission_2025/pma/libraries/classes/Import/SimulateDml.php

149 lines
4.9 KiB
PHP

<?php
declare(strict_types=1);
namespace PhpMyAdmin\Import;
use PhpMyAdmin\Core;
use PhpMyAdmin\DatabaseInterface;
use PhpMyAdmin\Html;
use PhpMyAdmin\SqlParser\Parser;
use PhpMyAdmin\SqlParser\Statement;
use PhpMyAdmin\SqlParser\Statements\DeleteStatement;
use PhpMyAdmin\SqlParser\Statements\UpdateStatement;
use PhpMyAdmin\SqlParser\Utils\Query;
use PhpMyAdmin\Url;
use PhpMyAdmin\Util;
use Webmozart\Assert\Assert;
use function array_key_exists;
use function array_reverse;
use function implode;
final class SimulateDml
{
/** @var DatabaseInterface */
private $dbi;
public function __construct(DatabaseInterface $dbi)
{
$this->dbi = $dbi;
}
public function getError(): string
{
return $this->dbi->getError();
}
/**
* Find the matching rows for UPDATE/DELETE query.
*
* @param DeleteStatement|UpdateStatement $statement
*
* @return array<string, int|string>|null
* @psalm-return array{
* sql_query: string,
* matched_rows: int,
* matched_rows_url: string
* }
*/
public function getMatchedRows(Parser $parser, Statement $statement): array
{
if ($statement instanceof DeleteStatement) {
$matchedRowsQuery = $this->getSimulatedDeleteQuery($parser, $statement);
} else {
$matchedRowsQuery = $this->getSimulatedUpdateQuery($parser, $statement);
}
// Execute the query and get the number of matched rows.
$matchedRows = $this->executeMatchedRowQuery($matchedRowsQuery);
$matchedRowsUrl = Url::getFromRoute('/sql', [
'db' => $GLOBALS['db'],
'sql_query' => $matchedRowsQuery,
'sql_signature' => Core::signSqlQuery($matchedRowsQuery),
]);
return [
'sql_query' => Html\Generator::formatSql($statement->build()),
'matched_rows' => $matchedRows,
'matched_rows_url' => $matchedRowsUrl,
];
}
/**
* Executes the matched_row_query and returns the resultant row count.
*
* @param string $matchedRowQuery SQL query
*/
private function executeMatchedRowQuery(string $matchedRowQuery): int
{
$this->dbi->selectDb($GLOBALS['db']);
$result = $this->dbi->tryQuery($matchedRowQuery);
if (! $result) {
return 0;
}
return (int) $result->numRows();
}
/**
* Transforms a DELETE query into SELECT statement.
*
* @return string SQL query
*/
private function getSimulatedDeleteQuery(Parser $parser, DeleteStatement $statement): string
{
$tableReferences = Query::getTables($statement);
Assert::count($tableReferences, 1, 'No joins allowed in simulation query');
Assert::notNull($parser->list, 'Parser list not set');
$condition = Query::getClause($statement, $parser->list, 'WHERE');
$where = $condition === '' ? '' : ' WHERE ' . $condition;
$order = $statement->order === null || $statement->order === []
? ''
: ' ORDER BY ' . Query::getClause($statement, $parser->list, 'ORDER BY');
$limit = $statement->limit === null ? '' : ' LIMIT ' . Query::getClause($statement, $parser->list, 'LIMIT');
return 'SELECT * FROM ' . $tableReferences[0] . $where . $order . $limit;
}
/**
* Transforms a UPDATE query into SELECT statement.
*
* @return string SQL query
*/
private function getSimulatedUpdateQuery(Parser $parser, UpdateStatement $statement): string
{
$tableReferences = Query::getTables($statement);
Assert::count($tableReferences, 1, 'No joins allowed in simulation query');
Assert::isNonEmptyList($statement->set, 'SET statements missing');
Assert::notNull($parser->list, 'Parser list not set');
$values = [];
$newColumns = [];
$oldColumns = [];
foreach (array_reverse($statement->set) as $set) {
$column = Util::unQuote($set->column);
if (array_key_exists($column, $values)) {
continue;
}
$oldColumns[] = Util::backquote($column);
$values[$column] = $set->value . ' AS ' . ($newColumns[] = Util::backquote($column . ' `new`'));
}
$condition = Query::getClause($statement, $parser->list, 'WHERE');
$where = $condition === '' ? '' : ' WHERE ' . $condition;
$order = $statement->order === null || $statement->order === []
? ''
: ' ORDER BY ' . Query::getClause($statement, $parser->list, 'ORDER BY');
$limit = $statement->limit === null ? '' : ' LIMIT ' . Query::getClause($statement, $parser->list, 'LIMIT');
return 'SELECT *' .
' FROM (' .
'SELECT *, ' . implode(', ', $values) . ' FROM ' . $tableReferences[0] . $where . $order . $limit .
') AS `pma_tmp`' .
' WHERE NOT (' . implode(', ', $oldColumns) . ') <=> (' . implode(', ', $newColumns) . ')';
}
}