OracleSchemaManager and OracleMetadataProvider ignore platform UnquotedIdentifierFolding when querying Oracle data dictionary, causing introspectTableByUnquotedName() to fail

[k0n3r]

Bug Report

Q	A
Version	4.4.1
Previous Version if the bug is a regression	unknown

Summary

OracleSchemaManager and OracleMetadataProvider pass table names as-is to Oracle's data dictionary queries without normalizing to uppercase. When the platform's
UnquotedIdentifierFolding is LOWER, Doctrine passes lowercase names like 'migrations' to WHERE TABLE_NAME = :TABLE_NAME, but Oracle's data dictionary always stores unquoted
identifiers as uppercase (MIGRATIONS), so the query returns nothing and introspectTableByUnquotedName() throws TableDoesNotExist.

Worth noting: OraclePlatform::__construct() hardcodes UnquotedIdentifierFolding::UPPER and doesn't accept it as a parameter, so the only way to use LOWER folding is by
subclassing and overriding the private property via reflection — which is what exposes this bug.

Current behavior

tablesExist(['migrations']) returns true, but introspectTableByUnquotedName('migrations') throws TableDoesNotExist immediately after on the same connection.

The call chain for introspectTableByUnquotedName('migrations'):

1. introspectTableObjects() calls $tableName->getUnqualifiedName()->toNormalizedValue($folding) — with LOWER folding this produces 'migrations'
2. That value is passed to selectTableColumns() / OracleMetadataProvider::buildTableQueryPredicate()
3. SQL ends up as WHERE C.TABLE_NAME = 'migrations'
4. Oracle's data dictionary has MIGRATIONS — no match, TableDoesNotExist is thrown

tablesExist() doesn't hit this because AbstractSchemaManager line 184 lowercases both sides before comparing, so migrations == strtolower('MIGRATIONS') passes — but the
introspection path has no equivalent normalization.

Affected methods:

• OracleSchemaManager::selectTableColumns()
• OracleSchemaManager::selectIndexColumns()
• OracleSchemaManager::selectForeignKeyColumns()
• OracleSchemaManager::fetchTableOptionsByTable()
• OracleMetadataProvider::buildTableQueryPredicate()

Expected behavior

introspectTableByUnquotedName('migrations') should find the table. Oracle's data dictionary is always uppercase for unquoted identifiers — that's an Oracle fact, independent of
the platform's folding setting. The catalog query parameters should always go through strtoupper() before being bound, regardless of what getUnquotedIdentifierFolding() returns.

Also, OraclePlatform::__construct() should ideally accept UnquotedIdentifierFolding as an optional parameter instead of hardcoding UPPER, so users don't have to reach for
reflection to configure it.

How to reproduce

use Doctrine\DBAL\Platforms\OraclePlatform;
use Doctrine\DBAL\Schema\Name\UnquotedIdentifierFolding;

// OraclePlatform::__construct() hardcodes UPPER and accepts no parameters.
// The only way to get LOWER folding is via subclass + reflection:
class CustomOraclePlatform extends OraclePlatform
{
public function __construct()
{
parent::__construct();

      $reflection = new \ReflectionClass(\Doctrine\DBAL\Platforms\AbstractPlatform::class);
      $property   = $reflection->getProperty('unquotedIdentifierFolding');
      $property->setAccessible(true);
      $property->setValue($this, UnquotedIdentifierFolding::LOWER);
  }

}

// With a connection using this platform and a table MIGRATIONS existing in Oracle:
$schemaManager->tablesExist(['migrations']); // true
$schemaManager->introspectTableByUnquotedName('migrations'); // throws TableDoesNotExist

This is related to #7328, which hits a similar inconsistency between tablesExist() and the OracleMetadataProvider path from a different angle. The same pattern also appears in
doctrine/orm — SQLResultCasing hardcodes strtoupper() for OraclePlatform without consulting getUnquotedIdentifierFolding(), breaking hydration when ColumnCase::LOWER is used on
the connection (reported in doctrine/orm#12272).