Add PostgreSQL version of SQLite integ tests

- Add PostgreSQL throwaway database
- Add optional length parameter for random string
- Fix syntax for PostgreSQL in several areas
- Add optional ID for whereById type determination

tests/integration/postgresql/CountTest.php

@@ -0,0 +1,47 @@
+<?php declare(strict_types=1);
+
+namespace Test\Integration\PostgreSQL;
+
+use BitBadger\PDODocument\{Count, Field};
+use PHPUnit\Framework\Attributes\TestDox;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * PostgreSQL integration tests for the Count class
+ */
+#[TestDox('Count (PostgreSQL integration)')]
+class CountTest extends TestCase
+{
+    /** @var string Database name for throwaway database */
+    private string $dbName;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->dbName = ThrowawayDb::create();
+    }
+
+    protected function tearDown(): void
+    {
+        ThrowawayDb::destroy($this->dbName);
+        parent::tearDown();
+    }
+
+    public function testAllSucceeds(): void
+    {
+        $count = Count::all(ThrowawayDb::TABLE);
+        $this->assertEquals(5, $count, 'There should have been 5 matching documents');
+    }
+
+    public function testByFieldsSucceedsForANumericRange(): void
+    {
+        $count = Count::byFields(ThrowawayDb::TABLE, [Field::BT('num_value', 10, 20)]);
+        $this->assertEquals(3, $count, 'There should have been 3 matching documents');
+    }
+
+    public function testByFieldsSucceedsForANonNumericRange(): void
+    {
+        $count = Count::byFields(ThrowawayDb::TABLE, [Field::BT('value', 'aardvark', 'apple')]);
+        $this->assertEquals(1, $count, 'There should have been 1 matching document');
+    }
+}