diff --git a/system/Model.php b/system/Model.php
index 68c176f99751..1b395d3fcd63 100644
--- a/system/Model.php
+++ b/system/Model.php
@@ -727,6 +727,7 @@ public function update($id = null, $data = null)
 		{
 			if ($this->validate($data) === false)
 			{
+				dd($this->errors());
 				return false;
 			}
 		}
@@ -1254,17 +1255,27 @@ public function validate($data): bool
 			$data = (array) $data;
 		}
 
+		$rules = $this->validationRules;
+		$rules = $this->cleanValidationRules($rules, $data);
+
+		// If no data existed that needs validation
+		// our job is done here.
+		if (empty($rules))
+		{
+			return true;
+		}
+
 		// ValidationRules can be either a string, which is the group name,
 		// or an array of rules.
-		if (is_string($this->validationRules))
+		if (is_string($rules))
 		{
-			$valid = $this->validation->run($data, $this->validationRules, $this->DBGroup);
+			$valid = $this->validation->run($data, $rules, $this->DBGroup);
 		}
 		else
 		{
 			// Replace any placeholders (i.e. {id}) in the rules with
 			// the value found in $data, if exists.
-			$rules = $this->fillPlaceholders($this->validationRules, $data);
+			$rules = $this->fillPlaceholders($rules, $data);
 
 			$this->validation->setRules($rules, $this->validationMessages);
 			$valid = $this->validation->run($data, null, $this->DBGroup);
@@ -1275,6 +1286,33 @@ public function validate($data): bool
 
 	//--------------------------------------------------------------------
 
+	/**
+	 * Removes any rules that apply to fields that have not been set
+	 * currently so that rules don't block updating when only updating
+	 * a partial row.
+	 *
+	 * @param array $rules
+	 *
+	 * @return array
+	 */
+	protected function cleanValidationRules(array $rules, array $data = null)
+	{
+		if (empty($data))
+		{
+			return [];
+		}
+
+		foreach ($rules as $field => $rule)
+		{
+			if (! array_key_exists($field, $data))
+			{
+				unset($rules[$field]);
+			}
+		}
+
+		return $rules;
+	}
+
 	/**
 	 * Replace any placeholders within the rules with the values that
 	 * match the 'key' of any properties being set. For example, if
diff --git a/tests/system/Database/Live/ModelTest.php b/tests/system/Database/Live/ModelTest.php
index ff45a2aef7f3..8b6e0ad37407 100644
--- a/tests/system/Database/Live/ModelTest.php
+++ b/tests/system/Database/Live/ModelTest.php
@@ -61,7 +61,8 @@ public function testFindActsAsGetWithNoParams()
 	{
 		$model = new JobModel($this->db);
 
-		$jobs = $model->asArray()->find();
+		$jobs = $model->asArray()
+					  ->find();
 
 		$this->assertCount(4, $jobs);
 
@@ -78,7 +79,8 @@ public function testFindRespectsReturnArray()
 	{
 		$model = new JobModel($this->db);
 
-		$job = $model->asArray()->find(4);
+		$job = $model->asArray()
+					 ->find(4);
 
 		$this->assertInternalType('array', $job);
 	}
@@ -89,7 +91,8 @@ public function testFindRespectsReturnObject()
 	{
 		$model = new JobModel($this->db);
 
-		$job = $model->asObject()->find(4);
+		$job = $model->asObject()
+					 ->find(4);
 
 		$this->assertInternalType('object', $job);
 	}
@@ -98,15 +101,19 @@ public function testFindRespectsReturnObject()
 
 	public function testFindRespectsSoftDeletes()
 	{
-		$this->db->table('user')->where('id', 4)->update(['deleted' => 1]);
+		$this->db->table('user')
+				 ->where('id', 4)
+				 ->update(['deleted' => 1]);
 
 		$model = new UserModel($this->db);
 
-		$user = $model->asObject()->find(4);
+		$user = $model->asObject()
+					  ->find(4);
 
 		$this->assertEmpty($user);
 
-		$user = $model->withDeleted()->find(4);
+		$user = $model->withDeleted()
+					  ->find(4);
 
 		// fix for PHP7.2
 		$count = is_array($user) ? count($user) : 1;
@@ -123,7 +130,8 @@ public function testFindClearsBinds()
 		$model->find(1);
 
 		// Binds should be reset to 0 after each one
-		$binds = $model->builder()->getBinds();
+		$binds = $model->builder()
+					   ->getBinds();
 		$this->assertCount(0, $binds);
 
 		$query = $model->getLastQuery();
@@ -167,7 +175,9 @@ public function testFindAllRespectsLimitsAndOffset()
 
 	public function testFindAllRespectsSoftDeletes()
 	{
-		$this->db->table('user')->where('id', 4)->update(['deleted' => 1]);
+		$this->db->table('user')
+				 ->where('id', 4)
+				 ->update(['deleted' => 1]);
 
 		$model = new UserModel($this->db);
 
@@ -175,7 +185,8 @@ public function testFindAllRespectsSoftDeletes()
 
 		$this->assertCount(3, $user);
 
-		$user = $model->withDeleted()->findAll();
+		$user = $model->withDeleted()
+					  ->findAll();
 
 		$this->assertCount(4, $user);
 	}
@@ -186,7 +197,8 @@ public function testFirst()
 	{
 		$model = new UserModel();
 
-		$user = $model->where('id >', 2)->first();
+		$user = $model->where('id >', 2)
+					  ->first();
 
 		// fix for PHP7.2
 		$count = is_array($user) ? count($user) : 1;
@@ -198,7 +210,9 @@ public function testFirst()
 
 	public function testFirstRespectsSoftDeletes()
 	{
-		$this->db->table('user')->where('id', 1)->update(['deleted' => 1]);
+		$this->db->table('user')
+				 ->where('id', 1)
+				 ->update(['deleted' => 1]);
 
 		$model = new UserModel();
 
@@ -209,7 +223,8 @@ public function testFirstRespectsSoftDeletes()
 		$this->assertEquals(1, $count);
 		$this->assertEquals(2, $user->id);
 
-		$user = $model->withDeleted()->first();
+		$user = $model->withDeleted()
+					  ->first();
 
 		$this->assertEquals(1, $user->id);
 	}
@@ -218,14 +233,16 @@ public function testFirstWithNoPrimaryKey()
 	{
 		$model = new SecondaryModel();
 
-		$this->db->table('secondary')->insert([
-			'key'   => 'foo',
-			'value' => 'bar',
-		]);
-		$this->db->table('secondary')->insert([
-			'key'   => 'bar',
-			'value' => 'baz',
-		]);
+		$this->db->table('secondary')
+				 ->insert([
+					 'key'   => 'foo',
+					 'value' => 'bar',
+				 ]);
+		$this->db->table('secondary')
+				 ->insert([
+					 'key'   => 'bar',
+					 'value' => 'baz',
+				 ]);
 
 		$record = $model->first();
 
@@ -243,7 +260,8 @@ public function testSaveNewRecordObject()
 		$data->name        = 'Magician';
 		$data->description = 'Makes peoples things dissappear.';
 
-		$model->protect(false)->save($data);
+		$model->protect(false)
+			  ->save($data);
 
 		$this->seeInDatabase('job', ['name' => 'Magician']);
 	}
@@ -259,7 +277,8 @@ public function testSaveNewRecordArray()
 			'description' => 'That thing you do.',
 		];
 
-		$result = $model->protect(false)->save($data);
+		$result = $model->protect(false)
+						->save($data);
 
 		$this->seeInDatabase('job', ['name' => 'Apprentice']);
 	}
@@ -276,7 +295,8 @@ public function testSaveUpdateRecordObject()
 			'description' => 'That thing you do.',
 		];
 
-		$result = $model->protect(false)->save($data);
+		$result = $model->protect(false)
+						->save($data);
 
 		$this->seeInDatabase('job', ['name' => 'Apprentice']);
 		$this->assertTrue($result);
@@ -293,7 +313,8 @@ public function testSaveUpdateRecordArray()
 		$data->name        = 'Engineer';
 		$data->description = 'A fancier term for Developer.';
 
-		$result = $model->protect(false)->save($data);
+		$result = $model->protect(false)
+						->save($data);
 
 		$this->seeInDatabase('job', ['name' => 'Engineer']);
 		$this->assertTrue($result);
@@ -311,7 +332,8 @@ public function testSaveProtected()
 		$data->description  = 'A fancier term for Developer.';
 		$data->random_thing = 'Something wicked'; // If not protected, this would kill the script.
 
-		$result = $model->protect(true)->save($data);
+		$result = $model->protect(true)
+						->save($data);
 
 		$this->assertTrue($result);
 	}
@@ -379,7 +401,8 @@ public function testDeleteNoParams()
 
 		$this->seeInDatabase('job', ['name' => 'Developer']);
 
-		$model->where('id', 1)->delete();
+		$model->where('id', 1)
+			  ->delete();
 
 		$this->dontSeeInDatabase('job', ['name' => 'Developer']);
 	}
@@ -390,11 +413,14 @@ public function testPurgeDeleted()
 	{
 		$model = new UserModel();
 
-		$this->db->table('user')->where('id', 1)->update(['deleted' => 1]);
+		$this->db->table('user')
+				 ->where('id', 1)
+				 ->update(['deleted' => 1]);
 
 		$model->purgeDeleted();
 
-		$users = $model->withDeleted()->findAll();
+		$users = $model->withDeleted()
+					   ->findAll();
 
 		$this->assertCount(3, $users);
 	}
@@ -405,9 +431,12 @@ public function testOnlyDeleted()
 	{
 		$model = new UserModel($this->db);
 
-		$this->db->table('user')->where('id', 1)->update(['deleted' => 1]);
+		$this->db->table('user')
+				 ->where('id', 1)
+				 ->update(['deleted' => 1]);
 
-		$users = $model->onlyDeleted()->findAll();
+		$users = $model->onlyDeleted()
+					   ->findAll();
 
 		$this->assertCount(1, $users);
 	}
@@ -434,6 +463,7 @@ public function testValidationBasics()
 		$model = new ValidModel($this->db);
 
 		$data = [
+			'name'        => null,
 			'description' => 'some great marketing stuff',
 		];
 
@@ -481,7 +511,77 @@ public function testSkipValidation()
 			'description' => 'some great marketing stuff',
 		];
 
-		$this->assertInternalType('numeric', $model->skipValidation(true)->insert($data));
+		$this->assertInternalType('numeric', $model->skipValidation(true)
+												   ->insert($data));
+	}
+
+	public function testCleanValidationRemovesAllWhenNoDataProvided()
+	{
+		$model   = new Model($this->db);
+		$cleaner = $this->getPrivateMethodInvoker($model, 'cleanValidationRules');
+
+		$rules = [
+			'name' => 'required',
+			'foo'  => 'bar',
+		];
+
+		$rules = $cleaner($rules, null);
+
+		$this->assertEmpty($rules);
+	}
+
+	public function testCleanValidationRemovesOnlyForFieldsNotProvided()
+	{
+		$model   = new Model($this->db);
+		$cleaner = $this->getPrivateMethodInvoker($model, 'cleanValidationRules');
+
+		$rules = [
+			'name' => 'required',
+			'foo'  => 'required',
+		];
+
+		$data = [
+			'foo' => 'bar',
+		];
+
+		$rules = $cleaner($rules, $data);
+
+		$this->assertTrue(array_key_exists('foo', $rules));
+		$this->assertFalse(array_key_exists('name', $rules));
+	}
+
+	public function testCleanValidationReturnsAllWhenAllExist()
+	{
+		$model   = new Model($this->db);
+		$cleaner = $this->getPrivateMethodInvoker($model, 'cleanValidationRules');
+
+		$rules = [
+			'name' => 'required',
+			'foo'  => 'required',
+		];
+
+		$data = [
+			'foo'  => 'bar',
+			'name' => null,
+		];
+
+		$rules = $cleaner($rules, $data);
+
+		$this->assertTrue(array_key_exists('foo', $rules));
+		$this->assertTrue(array_key_exists('name', $rules));
+	}
+
+	public function testValidationPassesWithMissingFields()
+	{
+		$model = new ValidModel();
+
+		$data = [
+			'foo' => 'bar',
+		];
+
+		$result = $model->validate($data);
+
+		$this->assertTrue($result);
 	}
 
 	//--------------------------------------------------------------------
@@ -490,7 +590,8 @@ public function testCanCreateAndSaveEntityClasses()
 	{
 		$model = new EntityModel($this->db);
 
-		$entity = $model->where('name', 'Developer')->first();
+		$entity = $model->where('name', 'Developer')
+						->first();
 
 		$this->assertInstanceOf(SimpleEntity::class, $entity);
 		$this->assertEquals('Developer', $entity->name);
@@ -593,7 +694,8 @@ public function testSetWorksWithInsert()
 			'email'   => 'foo@example.com',
 			'name'    => 'Foo Bar',
 			'country' => 'US',
-		])->insert();
+		])
+			  ->insert();
 
 		$this->seeInDatabase('user', [
 			'email' => 'foo@example.com',
@@ -616,7 +718,8 @@ public function testSetWorksWithUpdate()
 
 		$model->set([
 			'name' => 'Fred Flintstone',
-		])->update($userId);
+		])
+			  ->update($userId);
 
 		$this->seeInDatabase('user', [
 			'id'    => $userId,
@@ -643,7 +746,8 @@ public function testSetWorksWithUpdateNoId()
 			->where('id', $userId)
 			->set([
 				'name' => 'Fred Flintstone',
-			])->update();
+			])
+			->update();
 
 		$this->seeInDatabase('user', [
 			'id'    => $userId,
@@ -768,7 +872,9 @@ public function testSelectAndEntitiesSaveOnlyChangedValues()
 
 		$model = new EntityModel();
 
-		$job = $model->select('id, name')->where('name', 'Rocket Scientist')->first();
+		$job = $model->select('id, name')
+					 ->where('name', 'Rocket Scientist')
+					 ->first();
 
 		$this->assertNull($job->description);
 		$this->assertEquals('Rocket Scientist', $job->name);
@@ -786,17 +892,19 @@ public function testUpdateNoPrimaryKey()
 	{
 		$model = new SecondaryModel();
 
-		$this->db->table('secondary')->insert([
-			'key'   => 'foo',
-			'value' => 'bar',
-		]);
+		$this->db->table('secondary')
+				 ->insert([
+					 'key'   => 'foo',
+					 'value' => 'bar',
+				 ]);
 
 		$this->dontSeeInDatabase('secondary', [
 			'key'   => 'bar',
 			'value' => 'baz',
 		]);
 
-		$model->where('key', 'foo')->update(null, ['key' => 'bar', 'value' => 'baz']);
+		$model->where('key', 'foo')
+			  ->update(null, ['key' => 'bar', 'value' => 'baz']);
 
 		$this->seeInDatabase('secondary', [
 			'key'   => 'bar',
@@ -814,8 +922,34 @@ public function testCountAllResultsRespectsSoftDeletes()
 		// testSeeder has 4 users....
 		$this->assertEquals(4, $model->countAllResults());
 
-		$model->where('name', 'Derek Jones')->delete();
+		$model->where('name', 'Derek Jones')
+			  ->delete();
 
 		$this->assertEquals(3, $model->countAllResults());
 	}
+
+	/**
+	 * @see https://github.com/codeigniter4/CodeIgniter4/issues/1584
+	 */
+	public function testUpdateWithValidation()
+	{
+		$model = new ValidModel($this->db);
+
+		$data = [
+			'description' => 'This is a first test!',
+			'name'        => 'valid',
+			'id'          => 42,
+			'token'       => 42,
+		];
+
+		$id = $model->insert($data);
+
+		$this->assertTrue((bool)$id);
+
+		$data['description'] = 'This is a second test!';
+		unset($data['name']);
+
+		$result = $model->update($id, $data);
+		$this->assertTrue($result);
+	}
 }
diff --git a/tests/system/Validation/RulesTest.php b/tests/system/Validation/RulesTest.php
index 447e42dfb973..b2ddfafade9e 100644
--- a/tests/system/Validation/RulesTest.php
+++ b/tests/system/Validation/RulesTest.php
@@ -34,7 +34,7 @@ protected function setUp()
 	{
 		parent::setUp();
 
-		$this->validation = new Validation((object) $this->config, \Config\Services::renderer());
+		$this->validation = new Validation((object)$this->config, \Config\Services::renderer());
 		$this->validation->reset();
 
 		$_FILES = [];
@@ -51,7 +51,7 @@ public function testRequiredNull()
 		];
 
 		$this->validation->setRules([
-			'foo' => 'required',
+			'foo' => 'required|alpha',
 		]);
 
 		$this->assertFalse($this->validation->run($data));
@@ -77,6 +77,7 @@ public function testRequiredTrueString()
 	public function testRequiredFalseString()
 	{
 		$data = [
+			'foo' => null,
 			'bar' => 123,
 		];
 
@@ -160,7 +161,7 @@ public function ifExistProvider()
 			],
 			[
 				['foo' => 'required'],
-				[],
+				['foo' => null],
 				false,
 			],
 			[
@@ -387,11 +388,12 @@ public function testDiffersFalse()
 	public function testIsUniqueFalse()
 	{
 		$db = Database::connect();
-		$db->table('user')->insert([
-			'name'    => 'Derek Travis',
-			'email'   => 'derek@world.com',
-			'country' => 'Elbonia',
-		]);
+		$db->table('user')
+		   ->insert([
+			   'name'    => 'Derek Travis',
+			   'email'   => 'derek@world.com',
+			   'country' => 'Elbonia',
+		   ]);
 
 		$data = [
 			'email' => 'derek@world.com',
@@ -431,15 +433,15 @@ public function testIsUniqueIgnoresParams()
 	{
 		$db   = Database::connect();
 		$user = $db->table('user')
-				->insert([
-					'name'    => 'Developer A',
-					'email'   => 'deva@example.com',
-					'country' => 'Elbonia',
-				]);
+				   ->insert([
+					   'name'    => 'Developer A',
+					   'email'   => 'deva@example.com',
+					   'country' => 'Elbonia',
+				   ]);
 		$row  = $db->table('user')
-				->limit(1)
-				->get()
-				->getRow();
+				   ->limit(1)
+				   ->get()
+				   ->getRow();
 
 		$data = [
 			'email' => 'derek@world.co.uk',