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rebase: MSSQL adds a redundant ORDER BY clause when with subquery with ORDER BY #4455

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45 changes: 32 additions & 13 deletions lib/Doctrine/DBAL/Platforms/SQLServer2012Platform.php
Original file line number Diff line number Diff line change
Expand Up @@ -101,19 +101,7 @@ protected function doModifyLimitQuery($query, $limit, $offset = null)
}

// Queries using OFFSET... FETCH MUST have an ORDER BY clause
// Find the position of the last instance of ORDER BY and ensure it is not within a parenthetical statement
// but can be in a newline
$matches = [];
$matchesCount = preg_match_all('/[\\s]+order\\s+by\\s/im', $query, $matches, PREG_OFFSET_CAPTURE);
$orderByPos = false;
if ($matchesCount > 0) {
$orderByPos = $matches[0][$matchesCount - 1][1];
}

if (
$orderByPos === false
|| substr_count($query, '(', $orderByPos) - substr_count($query, ')', $orderByPos)
) {
if ($this->shouldAddOrderBy($query)) {
if (preg_match('/^SELECT\s+DISTINCT/im', $query)) {
// SQL Server won't let us order by a non-selected column in a DISTINCT query,
// so we have to do this madness. This says, order by the first column in the
Expand Down Expand Up @@ -143,4 +131,35 @@ protected function doModifyLimitQuery($query, $limit, $offset = null)

return $query;
}

/**
* @param string $query
*/
private function shouldAddOrderBy($query): bool
{
// Find the position of the last instance of ORDER BY and ensure it is not within a parenthetical statement
// but can be in a newline
$matches = [];
$matchesCount = preg_match_all('/[\\s]+order\\s+by\\s/im', $query, $matches, PREG_OFFSET_CAPTURE);
if ($matchesCount === 0) {
return true;
}

// ORDER BY instance may be in a subquery after ORDER BY
// e.g. SELECT col1 FROM test ORDER BY (SELECT col2 from test ORDER BY col2)
// if in the searched query ORDER BY clause was found where
// number of open parentheses after the occurrence of the clause is equal to
// number of closed brackets after the occurrence of the clause,
// it means that ORDER BY is included in the query being checked
while ($matchesCount > 0) {
$orderByPos = $matches[0][--$matchesCount][1];
$openBracketsCount = substr_count($query, '(', $orderByPos);
$closedBracketsCount = substr_count($query, ')', $orderByPos);
if ($openBracketsCount === $closedBracketsCount) {
return false;
}
}

return true;
}
}
40 changes: 40 additions & 0 deletions tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php
Original file line number Diff line number Diff line change
Expand Up @@ -2,11 +2,16 @@

namespace Doctrine\Tests\DBAL\Functional;

use Doctrine\DBAL\Platforms\DB2Platform;
use Doctrine\DBAL\Platforms\OraclePlatform;
use Doctrine\DBAL\Platforms\SQLServer2012Platform;
use Doctrine\DBAL\Platforms\SQLServerPlatform;
use Doctrine\DBAL\Schema\Table;
use Doctrine\Tests\DbalFunctionalTestCase;

use function array_change_key_case;
use function count;
use function preg_replace;

use const CASE_LOWER;

Expand Down Expand Up @@ -195,4 +200,39 @@ private function assertLimitResult(
self::assertCount(count($expectedResults), $data);
}
}

public function testLimitWhenOrderByWithSubqueryWithOrderBy(): void
{
$platform = $this->connection->getDatabasePlatform();
if ($platform instanceof DB2Platform) {
self::markTestSkipped('DB2 cannot handle ORDER BY in subquery');
}

if ($platform instanceof OraclePlatform) {
$this->markTestSkipped('Oracle cannot handle ORDER BY in subquery');
}

$this->connection->insert('modify_limit_table2', ['test_int' => 3]);
$this->connection->insert('modify_limit_table2', ['test_int' => 1]);
$this->connection->insert('modify_limit_table2', ['test_int' => 2]);

$subquery = 'SELECT test_int FROM modify_limit_table2 T2 WHERE T1.id=T2.id ORDER BY test_int';

// [SQL Server]The ORDER BY clause is invalid in views, inline functions, derived tables, subqueries,
// and common table expressions, unless TOP, OFFSET or FOR XML is also specified.
if (
$platform instanceof SQLServerPlatform
&& ! $platform instanceof SQLServer2012Platform
) {
$subquery = preg_replace('/^SELECT\s/i', 'SELECT TOP 1 ', $subquery);
}

if ($platform instanceof SQLServer2012Platform) {
$subquery .= ' OFFSET 0 ROWS';
}

$sql = 'SELECT test_int FROM modify_limit_table2 T1 ORDER BY (' . $subquery . ') ASC';

$this->assertLimitResult([1, 2, 3], $sql, 10, 0);
}
}
10 changes: 10 additions & 0 deletions tests/Doctrine/Tests/DBAL/Platforms/SQLServer2012PlatformTest.php
Original file line number Diff line number Diff line change
Expand Up @@ -479,4 +479,14 @@ public function testModifyLimitQueryWithNewlineBeforeOrderBy(): void
$sql = $this->platform->modifyLimitQuery($querySql, 10);
self::assertEquals($expectedSql, $sql);
}

public function testModifyLimitQueryWithOrderByWithSubqueryWithOrderBy(): void
{
$subquery = 'SELECT col2 from test ORDER BY col2 OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY';
$querySql = 'SELECT col1 FROM test ORDER BY ( ' . $subquery . ' )';
$expectedSql = 'SELECT col1 FROM test ORDER BY ( ' . $subquery . ' )'
. ' OFFSET 0 ROWS FETCH NEXT 10 ROWS ONLY';
$sql = $this->platform->modifyLimitQuery($querySql, 10);
self::assertEquals($expectedSql, $sql);
}
}