Add classes and tests from common project

tests/unit/Query/DeleteTest.php

@@ -0,0 +1,26 @@
+<?php declare(strict_types=1);
+
+namespace Test\Unit\Query;
+
+use BitBadger\PDODocument\Field;
+use BitBadger\PDODocument\Query\Delete;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Unit tests for the Delete class
+ */
+class DeleteTest extends TestCase
+{
+    public function testByIdSucceeds(): void
+    {
+        $this->assertEquals("DELETE FROM over_there WHERE data->>'id' = @id", Delete::byId('over_there'),
+            'DELETE statement not constructed correctly');
+    }
+
+    public function testByFieldsSucceeds(): void
+    {
+        $this->assertEquals("DELETE FROM my_table WHERE data->>'value' < @max AND data->>'value' >= @min",
+            Delete::byFields('my_table', [Field::LT('value', 99, '@max'), Field::GE('value', 18, '@min')]),
+            'DELETE statement not constructed correctly');
+    }
+}