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Incorrect type in SelectStatement::$expr when query has CASE-clause in selected fields #552
Description
The public field SelectStatement::$expr is defined in a PHP docblock as an Expression[]. When parsing a query with a CASE statement, a CaseExpression object is present in this list, despite CaseExpression not extending Expression. This causes issues when explicitly requiring the Expression type as should be returned by SelectStatement::$expr.
Reproduction case
<?php
declare(strict_types=1);
use PhpMyAdmin\SqlParser\Components\Expression;
use PhpMyAdmin\SqlParser\Parser;
use PhpMyAdmin\SqlParser\Statements\SelectStatement;
include_once 'vendor/autoload.php';
$p = new Parser('SELECT a, CASE WHEN b IS NOT NULL THEN 1 ELSE 0 END as c FROM t');
$stmt = $p->statements[0];
if (! $stmt instanceof SelectStatement) {
throw new Exception('Could not parse select statement');
}
function acceptExpression(Expression $e): void {}
$expressions = $stmt->expr;
foreach ($expressions as $expression) {
acceptExpression($expression);
}Expected behavior
I would expect this script to not error out as the $stmt->expr returns Expression[] according to its PHP docblock. Each element should therefore be compatible with Expression in my acceptExpression function.
Real behavior
$ php test.php
PHP Fatal error: Uncaught TypeError: acceptExpression(): Argument #1 ($e) must be of type PhpMyAdmin\SqlParser\Components\Expression, PhpMyAdmin\SqlParser\Components\CaseExpression given, called in /path/to/test.php on line 22 and defined in /path/to/test.php:18
Stack trace:
#0 /path/to/test.php(22): acceptExpression()
#1 {main}
thrown in /path/to/test.php on line 18
Activity
williamdes commentedon Feb 29, 2024
Hello
What version of sql-parser are you using?
Daniel-I-Am commentedon Feb 29, 2024
This is on the latest release of sql-parser, 5.9.0, with PHP 8.2.
williamdes commentedon Feb 29, 2024
@MauricioFauth could you please have a look?
kamil-tekiela commentedon Feb 29, 2024
This was added #88
I noticed this issue before but I have no idea how to fix this. CaseExpression cannot inherit from Expression, but all of the code is written around the value being only Expression.
niconoe- commentedon Sep 20, 2024
#583 Defines now that
SelectStatement::$exprcan be of typeCaseExpression[].@Daniel-I-Am , your snippet will still cause an error as this is just a change in the PHPDoc, but at least, the PHPDoc will be valid and you could change your behavior to
As @kamil-tekiela said,
CaseExpressioncannot inherit fromExpression, so I think that's the best we could provide.