[ticket/16741] Specific DBs fixes

MSSQL:
- Fix bool type
- Fix comparator
- Drop Default constraint before deleting column
- Rename Default constraint to use phpBB's names
- Re-create the indices when changing the type of one column
- Uses varchar instead of varbinary

PostgreSQL:
- Creates auto increment sequences by hand instead of using serial
  in order to use phpBB's names
- Drop constraint on unique / primary indices

Oracle:
- Rename indices to use phpBB's names
- Fix string not null behaviour
- Fix broken regex in Oracle driver
- Handle to long indices on Oracle
- Rename auto_increment trigger and sequence
- Automatically lowercase keys in assoc results

PHPBB3-16741

phpBB/phpbb/db/doctrine/postgresql_platform.php

@@ -0,0 +1,178 @@
+<?php
+/**
+ *
+ * This file is part of the phpBB Forum Software package.
+ *
+ * @copyright (c) phpBB Limited <https://www.phpbb.com>
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ * For full copyright and license information, please see
+ * the docs/CREDITS.txt file.
+ *
+ */
+
+namespace phpbb\db\doctrine;
+
+use Doctrine\DBAL\Platforms\AbstractPlatform;
+use Doctrine\DBAL\Platforms\PostgreSQL94Platform;
+use Doctrine\DBAL\Schema\Index;
+use Doctrine\DBAL\Schema\Sequence;
+use Doctrine\DBAL\Schema\Table;
+use Doctrine\DBAL\Types\BigIntType;
+use Doctrine\DBAL\Types\IntegerType;
+use Doctrine\DBAL\Types\SmallIntType;
+use Doctrine\DBAL\Types\Type;
+
+/**
+ * PostgreSQL specific schema restrictions for BC.
+ *
+ * Doctrine is using SERIAL which auto creates the sequences with
+ * a name different from the one our driver is using. So in order
+ * to stay compatible with the existing DB we have to change its
+ * naming and not ours.
+ */
+class postgresql_platform extends PostgreSQL94Platform
+{
+	/**
+	 * {@inheritdoc}
+	 */
+	public function getIdentitySequenceName($tableName, $columnName)
+	{
+		return $tableName . '_seq';
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function getIntegerTypeDeclarationSQL(array $column)
+	{
+		return 'INT';
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function getBigIntTypeDeclarationSQL(array $column)
+	{
+		return 'BIGINT';
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function getSmallIntTypeDeclarationSQL(array $column)
+	{
+		return 'SMALLINT';
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function getDefaultValueDeclarationSQL($column)
+	{
+		if ($this->isSerialColumn($column))
+		{
+			return ' DEFAULT {{placeholder_sequence}}';
+		}
+
+		return AbstractPlatform::getDefaultValueDeclarationSQL($column);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function supportsIdentityColumns()
+	{
+		return false;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	protected function _getCreateTableSQL($name, array $columns, array $options = [])
+	{
+		$sql = [];
+		$post_sql = [];
+		foreach ($columns as $column_name => $column)
+		{
+			if (! empty($column['autoincrement']))
+			{
+				$sequence = new Sequence($this->getIdentitySequenceName($name, $column_name));
+				$sql[] = $this->getCreateSequenceSQL($sequence);
+				$post_sql[] = 'ALTER SEQUENCE '.$sequence->getName().' OWNED BY '.$name.'.'.$column_name;
+			}
+		}
+		$sql = array_merge($sql, parent::_getCreateTableSQL($name, $columns, $options), $post_sql);
+
+		foreach ($sql as $i => $query)
+		{
+			$sql[$i] = str_replace('{{placeholder_sequence}}', "nextval('{$name}_seq')", $query);
+		}
+
+		return $sql;
+	}
+
+	/**
+	 * @param mixed[] $column
+	 */
+	private function isSerialColumn(array $column): bool
+	{
+		return isset($column['type'], $column['autoincrement'])
+			&& $column['autoincrement'] === true
+			&& $this->isNumericType($column['type']);
+	}
+
+	private function isNumericType(Type $type): bool
+	{
+		return $type instanceof IntegerType || $type instanceof BigIntType || $type instanceof SmallIntType;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function getListSequencesSQL($database)
+	{
+		return "SELECT sequence_name AS relname,
+                       sequence_schema AS schemaname,
+                       1 AS min_value,
+                       1 AS increment_by
+                FROM   information_schema.sequences
+                WHERE  sequence_schema NOT LIKE 'pg\_%'
+                AND    sequence_schema != 'information_schema'";
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function getDropIndexSQL($index, $table = null)
+	{
+		// If we have a primary or a unique index, we need to drop the constraint
+		// instead of the index itself or postgreSQL will reject the query.
+		if ($index instanceof Index)
+		{
+			if ($index->isPrimary())
+			{
+				if ($table instanceof Table)
+				{
+					$table = $table->getQuotedName($this);
+				}
+				else if (!is_string($table))
+				{
+					throw new \InvalidArgumentException(
+						__METHOD__ . '() expects $table parameter to be string or ' . Table::class . '.'
+					);
+				}
+
+				return 'ALTER TABLE '.$table.' DROP CONSTRAINT '.$index->getQuotedName($this);
+			}
+		}
+		else if (! is_string($index))
+		{
+			throw new \InvalidArgumentException(
+				__METHOD__ . '() expects $index parameter to be string or ' . Index::class . '.'
+			);
+		}
+
+		return parent::getDropIndexSQL($index, $table);
+	}
+}