<?php
declare(strict_types=1);
namespace PhpMyAdmin\SqlParser\Utils;
use PhpMyAdmin\SqlParser\Components\Expression;
use PhpMyAdmin\SqlParser\Statements\SelectStatement;
/**
* Miscellaneous utilities.
*/
class Misc
{
/**
* Gets a list of all aliases and their original names.
*
* @param SelectStatement $statement the statement to be processed
* @param string $database the name of the database
*
* @return array<string, array<string, array<string, array<string, array<string, string>|string|null>>|null>>
*/
public static function getAliases($statement, $database)
{
if (! ($statement instanceof SelectStatement) || empty($statement->expr) || empty($statement->from)) {
return [];
}
$retval = [];
$tables = [];
/**
* Expressions that may contain aliases.
* These are extracted from `FROM` and `JOIN` keywords.
*
* @var Expression[]
*/
$expressions = $statement->from;
// Adding expressions from JOIN.
if (! empty($statement->join)) {
foreach ($statement->join as $join) {
$expressions[] = $join->expr;
}
}
foreach ($expressions as $expr) {
if (! isset($expr->table) || ($expr->table === '')) {
continue;
}
$thisDb = isset($expr->database) && ($expr->database !== '') ?
$expr->database : $database;
if (! isset($retval[$thisDb])) {
$retval[$thisDb] = [
'alias' => null,
'tables' => [],
];
}
if (! isset($retval[$thisDb]['tables'][$expr->table])) {
$retval[$thisDb]['tables'][$expr->table] = [
'alias' => isset($expr->alias) && ($expr->alias !== '') ?
$expr->alias : null,
'columns' => [],
];
}
if (! isset($tables[$thisDb])) {
$tables[$thisDb] = [];
}
$tables[$thisDb][$expr->alias] = $expr->table;
}
foreach ($statement->expr as $expr) {
if (! isset($expr->column, $expr->alias) || ($expr->column === '') || ($expr->alias === '')) {
continue;
}
$thisDb = isset($expr->database) && ($expr->database !== '') ?
$expr->database : $database;
if (isset($expr->table) && ($expr->table !== '')) {
$thisTable = $tables[$thisDb][$expr->table] ?? $expr->table;
$retval[$thisDb]['tables'][$thisTable]['columns'][$expr->column] = $expr->alias;
} else {
foreach ($retval[$thisDb]['tables'] as &$table) {
$table['columns'][$expr->column] = $expr->alias;
}
}
}
return $retval;
}
}