Removed support for DB-generated UUIDs

UPGRADE.md

 # Upgrade to 3.0
 
+## BC BREAK: Removed support for DB-generated UUIDs
+
+The support for DB-generated UUIDs was removed as non-portable.
+Please generate UUIDs on the application side (e.g. using [ramsey/uuid](https://packagist.org/packages/ramsey/uuid)).
+
 ## BC BREAK: Changes in the `Doctrine\DBAL\Connection` API
 
 - The following methods have been removed as leaking internal implementation details: `::getHost()`, `::getPort()`, `::getUsername()`, `::getPassword()`.

src/Platforms/AbstractPlatform.php

@@ -583,20 +583,6 @@ abstract class AbstractPlatform
         throw DBALException::notSupported(__METHOD__);
     }
 
-    /**
-     * Returns the global unique identifier expression.
-     *
-     * @deprecated Use application-generated UUIDs instead
-     *
-     * @return string
-     *
-     * @throws DBALException If not supported on this platform.
-     */
-    public function getGuidExpression()
-    {
-        throw DBALException::notSupported(__METHOD__);
-    }
-
     /**
      * Returns the SQL snippet to get the average value of a column.
      *

src/Platforms/MySqlPlatform.php

@@ -79,16 +79,6 @@ class MySqlPlatform extends AbstractPlatform
         return 'RLIKE';
     }
 
-    /**
-     * {@inheritDoc}
-     *
-     * @deprecated Use application-generated UUIDs instead
-     */
-    public function getGuidExpression()
-    {
-        return 'UUID()';
-    }
-
     /**
      * {@inheritDoc}
      */

src/Platforms/OraclePlatform.php

@@ -89,16 +89,6 @@ class OraclePlatform extends AbstractPlatform
         return 'INSTR(' . $str . ', ' . $substr . ', ' . $startPos . ')';
     }
 
-    /**
-     * {@inheritDoc}
-     *
-     * @deprecated Use application-generated UUIDs instead
-     */
-    public function getGuidExpression()
-    {
-        return 'SYS_GUID()';
-    }
-
     /**
      * {@inheritdoc}
      */

src/Platforms/PostgreSQL94Platform.php

@@ -1030,16 +1030,6 @@ SQL
         return 'TIME(0) WITHOUT TIME ZONE';
     }
 
-    /**
-     * {@inheritDoc}
-     *
-     * @deprecated Use application-generated UUIDs instead
-     */
-    public function getGuidExpression()
-    {
-        return 'UUID_GENERATE_V4()';
-    }
-
     /**
      * {@inheritDoc}
      */

src/Platforms/SQLServer2012Platform.php

@@ -1083,16 +1083,6 @@ SQL
         return 'DROP VIEW ' . $name;
     }
 
-    /**
-     * {@inheritDoc}
-     *
-     * @deprecated Use application-generated UUIDs instead
-     */
-    public function getGuidExpression()
-    {
-        return 'NEWID()';
-    }
-
     /**
      * {@inheritDoc}
      */

src/Platforms/SqlitePlatform.php

@@ -41,19 +41,6 @@ class SqlitePlatform extends AbstractPlatform
         return 'REGEXP';
     }
 
-    /**
-     * {@inheritDoc}
-     *
-     * @deprecated Use application-generated UUIDs instead
-     */
-    public function getGuidExpression()
-    {
-        return "HEX(RANDOMBLOB(4)) || '-' || HEX(RANDOMBLOB(2)) || '-4' || "
-            . "SUBSTR(HEX(RANDOMBLOB(2)), 2) || '-' || "
-            . "SUBSTR('89AB', 1 + (ABS(RANDOM()) % 4), 1) || "
-            . "SUBSTR(HEX(RANDOMBLOB(2)), 2) || '-' || HEX(RANDOMBLOB(6))";
-    }
-
     /**
      * @param string $type
      *

tests/Functional/Ticket/DBAL421Test.php

-<?php
-
-namespace Doctrine\DBAL\Tests\Functional\Ticket;
-
-use Doctrine\DBAL\Tests\FunctionalTestCase;
-
-use function in_array;
-use function preg_match;
-
-/**
- * @group DBAL-421
- */
-class DBAL421Test extends FunctionalTestCase
-{
-    protected function setUp(): void
-    {
-        parent::setUp();
-
-        $platform = $this->connection->getDatabasePlatform()->getName();
-        if (in_array($platform, ['mysql', 'sqlite'])) {
-            return;
-        }
-
-        $this->markTestSkipped('Currently restricted to MySQL and SQLite.');
-    }
-
-    public function testGuidShouldMatchPattern(): void
-    {
-        $guid    = $this->connection->query($this->getSelectGuidSql())->fetchOne();
-        $pattern = '/[0-9A-F]{8}\-[0-9A-F]{4}\-[0-9A-F]{4}\-[8-9A-B][0-9A-F]{3}\-[0-9A-F]{12}/i';
-        self::assertEquals(1, preg_match($pattern, $guid), 'GUID does not match pattern');
-    }
-
-    /**
-     * This test does (of course) not proof that all generated GUIDs are
-     * random, it should however provide some basic confidence.
-     */
-    public function testGuidShouldBeRandom(): void
-    {
-        $statement = $this->connection->prepare($this->getSelectGuidSql());
-        $guids     = [];
-
-        for ($i = 0; $i < 99; $i++) {
-            $guid = $statement->execute()->fetchFirstColumn();
-            self::assertNotContains($guid, $guids, 'Duplicate GUID detected');
-            $guids[] = $guid;
-        }
-    }
-
-    private function getSelectGuidSql(): string
-    {
-        return 'SELECT ' . $this->connection->getDatabasePlatform()->getGuidExpression();
-    }
-}