diff --git a/app/Database/Migrations/20181031062503_create_user_variables.php b/app/Database/Migrations/20181031062503_create_user_variables.php
index 250c18c..0bbdf22 100644
--- a/app/Database/Migrations/20181031062503_create_user_variables.php
+++ b/app/Database/Migrations/20181031062503_create_user_variables.php
@@ -65,6 +65,7 @@ class Migration_create_user_variables extends Migration
 			],
 		]);
 		$this->forge->addKey('id', true);
+		$this->forge->addForeignKey('user_id', $config->dbTableUsers, 'id');
 		$this->forge->createTable($config->dbTableUserVariables, true);
 	}
 
@@ -78,6 +79,7 @@ class Migration_create_user_variables extends Migration
 	public function down()
 	{
 		$config = new AauthConfig();
+		$this->forge->dropForeignKey($config->dbTableUserVariables, $config->dbTableUserVariables . '_user_id_foreign');
 		$this->forge->dropTable($config->dbTableUserVariables, true);
 	}
 }
diff --git a/app/Database/Migrations/20181031063642_create_login_tokens.php b/app/Database/Migrations/20181031063642_create_login_tokens.php
index 4bc8a12..225db01 100644
--- a/app/Database/Migrations/20181031063642_create_login_tokens.php
+++ b/app/Database/Migrations/20181031063642_create_login_tokens.php
@@ -47,7 +47,7 @@ class Migration_create_login_tokens extends Migration
 			'user_id' => [
 				'type'       => 'INT',
 				'constraint' => 11,
-				'default'    => 0,
+				'unsigned'   => true,
 			],
 			'random_hash' => [
 				'type'       => 'VARCHAR',
@@ -62,6 +62,7 @@ class Migration_create_login_tokens extends Migration
 			'expires_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP',
 		]);
 		$this->forge->addKey('id', true);
+		$this->forge->addForeignKey('user_id', $config->dbTableUsers, 'id');
 		$this->forge->createTable($config->dbTableLoginTokens, true);
 	}
 
@@ -75,6 +76,7 @@ class Migration_create_login_tokens extends Migration
 	public function down()
 	{
 		$config = new AauthConfig();
+		$this->forge->dropForeignKey($config->dbTableLoginTokens, $config->dbTableLoginTokens . '_user_id_foreign');
 		$this->forge->dropTable($config->dbTableLoginTokens, true);
 	}
 }
diff --git a/app/Database/Migrations/20181031064311_create_group_variables.php b/app/Database/Migrations/20181031064311_create_group_variables.php
index 5ddc4d9..f43825d 100644
--- a/app/Database/Migrations/20181031064311_create_group_variables.php
+++ b/app/Database/Migrations/20181031064311_create_group_variables.php
@@ -65,6 +65,7 @@ class Migration_create_group_variables extends Migration
 			],
 		]);
 		$this->forge->addKey('id', true);
+		$this->forge->addForeignKey('group_id', $config->dbTableGroups, 'id');
 		$this->forge->createTable($config->dbTableGroupVariables, true);
 	}
 
@@ -78,6 +79,7 @@ class Migration_create_group_variables extends Migration
 	public function down()
 	{
 		$config = new AauthConfig();
+		$this->forge->dropForeignKey($config->dbTableGroupVariables, $config->dbTableGroupVariables . '_group_id_foreign');
 		$this->forge->dropTable($config->dbTableGroupVariables, true);
 	}
 }
diff --git a/app/Database/Migrations/20181031064431_create_group_to_user.php b/app/Database/Migrations/20181031064431_create_group_to_user.php
index fb108d1..69cf5d4 100644
--- a/app/Database/Migrations/20181031064431_create_group_to_user.php
+++ b/app/Database/Migrations/20181031064431_create_group_to_user.php
@@ -50,6 +50,8 @@ class Migration_create_group_to_user extends Migration
 			],
 		]);
 		$this->forge->addKey(['group_id', 'user_id'], true);
+		$this->forge->addForeignKey('user_id', $config->dbTableUsers, 'id');
+		$this->forge->addForeignKey('group_id', $config->dbTableGroups, 'id');
 		$this->forge->createTable($config->dbTableGroupToUser, true);
 	}
 
@@ -63,6 +65,8 @@ class Migration_create_group_to_user extends Migration
 	public function down()
 	{
 		$config = new AauthConfig();
+		$this->forge->dropForeignKey($config->dbTableGroupToUser, $config->dbTableGroupToUser . '_user_id_foreign');
+		$this->forge->dropForeignKey($config->dbTableGroupToUser, $config->dbTableGroupToUser . '_group_id_foreign');
 		$this->forge->dropTable($config->dbTableGroupToUser, true);
 	}
 }
diff --git a/app/Database/Migrations/20181031064550_create_group_to_group.php b/app/Database/Migrations/20181031064550_create_group_to_group.php
index 6ab0915..24f1e9b 100644
--- a/app/Database/Migrations/20181031064550_create_group_to_group.php
+++ b/app/Database/Migrations/20181031064550_create_group_to_group.php
@@ -50,6 +50,8 @@ class Migration_create_group_to_group extends Migration
 			],
 		]);
 		$this->forge->addKey(['group_id', 'subgroup_id'], true);
+		$this->forge->addForeignKey('group_id', $config->dbTableGroups, 'id');
+		$this->forge->addForeignKey('subgroup_id', $config->dbTableGroups, 'id');
 		$this->forge->createTable($config->dbTableGroupToGroup, true);
 	}
 
@@ -63,6 +65,8 @@ class Migration_create_group_to_group extends Migration
 	public function down()
 	{
 		$config = new AauthConfig();
+		$this->forge->dropForeignKey($config->dbTableGroupToGroup, $config->dbTableGroupToGroup . '_group_id_foreign');
+		$this->forge->dropForeignKey($config->dbTableGroupToGroup, $config->dbTableGroupToGroup . '_subgroup_id_foreign');
 		$this->forge->dropTable($config->dbTableGroupToGroup, true);
 	}
 }
diff --git a/app/Database/Migrations/20181031065111_create_perm_to_user.php b/app/Database/Migrations/20181031065111_create_perm_to_user.php
index 645c4ac..a8b8169 100644
--- a/app/Database/Migrations/20181031065111_create_perm_to_user.php
+++ b/app/Database/Migrations/20181031065111_create_perm_to_user.php
@@ -55,6 +55,8 @@ class Migration_create_perm_to_user extends Migration
 			],
 		]);
 		$this->forge->addKey(['perm_id', 'user_id'], true);
+		$this->forge->addForeignKey('perm_id', $config->dbTablePerms, 'id', 'CASCADE', 'CASCADE');
+		$this->forge->addForeignKey('user_id', $config->dbTableUsers, 'id', 'CASCADE', 'CASCADE');
 		$this->forge->createTable($config->dbTablePermToUser, true);
 	}
 
@@ -68,6 +70,8 @@ class Migration_create_perm_to_user extends Migration
 	public function down()
 	{
 		$config = new AauthConfig();
+		$this->forge->dropForeignKey($config->dbTablePermToUser, $config->dbTablePermToUser . '_perm_id_foreign');
+		$this->forge->dropForeignKey($config->dbTablePermToUser, $config->dbTablePermToUser . '_user_id_foreign');
 		$this->forge->dropTable($config->dbTablePermToUser, true);
 	}
 }
diff --git a/app/Database/Migrations/20181031065240_create_perm_to_group.php b/app/Database/Migrations/20181031065240_create_perm_to_group.php
index 12e7cde..fec765f 100644
--- a/app/Database/Migrations/20181031065240_create_perm_to_group.php
+++ b/app/Database/Migrations/20181031065240_create_perm_to_group.php
@@ -55,6 +55,8 @@ class Migration_create_perm_to_group extends Migration
 			],
 		]);
 		$this->forge->addKey(['perm_id', 'group_id'], true);
+		$this->forge->addForeignKey('perm_id', $config->dbTablePerms, 'id', 'CASCADE', 'CASCADE');
+		$this->forge->addForeignKey('group_id', $config->dbTableGroups, 'id', 'CASCADE', 'CASCADE');
 		$this->forge->createTable($config->dbTablePermToGroup, true);
 	}
 
@@ -68,6 +70,8 @@ class Migration_create_perm_to_group extends Migration
 	public function down()
 	{
 		$config = new AauthConfig();
+		$this->forge->dropForeignKey($config->dbTablePermToGroup, $config->dbTablePermToGroup . '_perm_id_foreign');
+		$this->forge->dropForeignKey($config->dbTablePermToGroup, $config->dbTablePermToGroup . '_group_id_foreign');
 		$this->forge->dropTable($config->dbTablePermToGroup, true);
 	}
 }
diff --git a/app/Database/Migrations/20181031072542_create_default_groups.php b/app/Database/Migrations/20181031072542_create_default_groups.php
index afe2dba..76e009e 100644
--- a/app/Database/Migrations/20181031072542_create_default_groups.php
+++ b/app/Database/Migrations/20181031072542_create_default_groups.php
@@ -37,20 +37,35 @@ class Migration_create_default_groups extends Migration
 	public function up()
 	{
 		$config = new AauthConfig();
-		$data   = [
-			[
-				'name'       => $config->groupAdmin,
-				'definition' => 'Administators',
-			],
-			[
-				'name'       => $config->groupDefault,
-				'definition' => 'Users',
-			],
-			[
-				'name'       => $config->groupPublic,
-				'definition' => 'Guests',
-			],
+
+		$adminGroup   = [
+			'name'       => $config->groupAdmin,
+			'definition' => 'Administators',
+		];
+		$defaultGroup = [
+			'name'       => $config->groupDefault,
+			'definition' => 'Users',
 		];
+		$publicGroup  = [
+			'name'       => $config->groupPublic,
+			'definition' => 'Guests',
+		];
+
+		if ($config->groupDefault)
+		{
+			$data = [
+				$adminGroup,
+				$defaultGroup,
+				$publicGroup,
+			];
+		}
+		else
+		{
+			$data = [
+				$adminGroup,
+				$publicGroup,
+			];
+		}
 
 		$this->db->table($config->dbTableGroups)->insertBatch($data);
 	}
@@ -65,6 +80,8 @@ class Migration_create_default_groups extends Migration
 	public function down()
 	{
 		$config = new AauthConfig();
+		$this->db->simpleQuery('SET FOREIGN_KEY_CHECKS = 0;');
 		$this->db->table($config->dbTableGroups)->truncate();
+		$this->db->simpleQuery('SET FOREIGN_KEY_CHECKS = 1;');
 	}
 }
diff --git a/app/Database/Migrations/20181031072914_create_default_users.php b/app/Database/Migrations/20181031072914_create_default_users.php
index 9ce8fb0..baf86bc 100644
--- a/app/Database/Migrations/20181031072914_create_default_users.php
+++ b/app/Database/Migrations/20181031072914_create_default_users.php
@@ -61,11 +61,15 @@ class Migration_create_default_users extends Migration
 				'group_id' => 2,
 				'user_id'  => 1,
 			],
-			[
+		];
+
+		if ($config->groupDefault)
+		{
+			$data[] = [
 				'group_id' => 2,
 				'user_id'  => 2,
-			],
-		];
+			];
+		}
 
 		$this->db->table($config->dbTableGroupToUser)->insertBatch($data);
 	}
@@ -80,7 +84,9 @@ class Migration_create_default_users extends Migration
 	public function down()
 	{
 		$config = new AauthConfig();
+		$this->db->simpleQuery('SET FOREIGN_KEY_CHECKS = 0;');
 		$this->db->table($config->dbTableUsers)->truncate();
 		$this->db->table($config->dbTableGroupToUser)->truncate();
+		$this->db->simpleQuery('SET FOREIGN_KEY_CHECKS = 1;');
 	}
 }