diff --git a/README.md b/README.md
index f4698da..3d73128 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # PHP-CRUD-API
 
-Single file PHP 7 script that adds a REST API to a MySQL/MariaDB, PostgreSQL, SQL Server or SQLite database. 
+Single file PHP script that adds a REST API to a MySQL/MariaDB, PostgreSQL, SQL Server or SQLite database. 
 
 NB: This is the [TreeQL](https://treeql.org) reference implementation in PHP.
 
@@ -55,6 +55,9 @@ Alternatively you can integrate this project into the web framework of your choi
 
 In these integrations [Composer](https://getcomposer.org/) is used to load this project as a dependency.
 
+For people that don't use composer, the file "`api.include.php`" is provided. This file contains everything 
+from "`api.php`" except the configuration from "`src/index.php`" and can be used by PHP's "include".
+
 ## Configuration
 
 Edit the following lines in the bottom of the file "`api.php`":
@@ -1207,7 +1210,7 @@ I am testing mainly on Ubuntu and I have the following test setups:
   - (Docker) Ubuntu 18.04 with PHP 7.2, MySQL 5.7, PostgreSQL 10.4 (PostGIS 2.4) and SQLite 3.22
   - (Docker) Debian 10 with PHP 7.3, MariaDB 10.3, PostgreSQL 11.4 (PostGIS 2.5) and SQLite 3.27
   - (Docker) Ubuntu 20.04 with PHP 7.4, MySQL 8.0, PostgreSQL 12.2 (PostGIS 3.0) and SQLite 3.31
-  - (Docker) CentOS 8 with PHP 7.4, MariaDB 10.5, PostgreSQL 12.5 (PostGIS 3.0) and SQLite 3.26
+  - (Docker) CentOS 8 with PHP 8.0, MariaDB 10.5, PostgreSQL 12.5 (PostGIS 3.0) and SQLite 3.26
 
 This covers not all environments (yet), so please notify me of failing tests and report your environment. 
 I will try to cover most relevant setups in the "docker" folder of the project.
@@ -1261,17 +1264,17 @@ Install docker using the following commands and then logout and login for the ch
 To run the docker tests run "build_all.sh" and "run_all.sh" from the docker directory. The output should be:
 
     ================================================
-    CentOS 8 (PHP 7.4)
+    CentOS 8 (PHP 8.0)
     ================================================
     [1/4] Starting MariaDB 10.5 ..... done
     [2/4] Starting PostgreSQL 12.5 .. done
     [3/4] Starting SQLServer 2017 ... skipped
     [4/4] Cloning PHP-CRUD-API v2 ... skipped
     ------------------------------------------------
-    mysql: 110 tests ran in 1911 ms, 1 skipped, 0 failed
-    pgsql: 110 tests ran in 1112 ms, 1 skipped, 0 failed
+    mysql: 110 tests ran in 957 ms, 1 skipped, 0 failed
+    pgsql: 110 tests ran in 817 ms, 1 skipped, 0 failed
     sqlsrv: skipped, driver not loaded
-    sqlite: 110 tests ran in 1178 ms, 12 skipped, 0 failed
+    sqlite: 110 tests ran in 685 ms, 12 skipped, 0 failed
     ================================================
     Debian 10 (PHP 7.3)
     ================================================
@@ -1280,10 +1283,10 @@ To run the docker tests run "build_all.sh" and "run_all.sh" from the docker dire
     [3/4] Starting SQLServer 2017 ... skipped
     [4/4] Cloning PHP-CRUD-API v2 ... skipped
     ------------------------------------------------
-    mysql: 110 tests ran in 3459 ms, 1 skipped, 0 failed
-    pgsql: 110 tests ran in 1134 ms, 1 skipped, 0 failed
+    mysql: 110 tests ran in 952 ms, 1 skipped, 0 failed
+    pgsql: 110 tests ran in 816 ms, 1 skipped, 0 failed
     sqlsrv: skipped, driver not loaded
-    sqlite: 110 tests ran in 1275 ms, 12 skipped, 0 failed
+    sqlite: 110 tests ran in 690 ms, 12 skipped, 0 failed
     ================================================
     Debian 9 (PHP 7.0)
     ================================================
@@ -1292,10 +1295,10 @@ To run the docker tests run "build_all.sh" and "run_all.sh" from the docker dire
     [3/4] Starting SQLServer 2017 ... skipped
     [4/4] Cloning PHP-CRUD-API v2 ... skipped
     ------------------------------------------------
-    mysql: 110 tests ran in 3181 ms, 1 skipped, 0 failed
-    pgsql: 110 tests ran in 1201 ms, 1 skipped, 0 failed
+    mysql: 110 tests ran in 1075 ms, 1 skipped, 0 failed
+    pgsql: 110 tests ran in 834 ms, 1 skipped, 0 failed
     sqlsrv: skipped, driver not loaded
-    sqlite: 110 tests ran in 1414 ms, 12 skipped, 0 failed
+    sqlite: 110 tests ran in 728 ms, 12 skipped, 0 failed
     ================================================
     Ubuntu 16.04 (PHP 7.0)
     ================================================
@@ -1304,9 +1307,9 @@ To run the docker tests run "build_all.sh" and "run_all.sh" from the docker dire
     [3/4] Starting SQLServer 2017 ... done
     [4/4] Cloning PHP-CRUD-API v2 ... skipped
     ------------------------------------------------
-    mysql: 110 tests ran in 3168 ms, 1 skipped, 0 failed
-    pgsql: 110 tests ran in 1197 ms, 1 skipped, 0 failed
-    sqlsrv: 110 tests ran in 10151 ms, 1 skipped, 0 failed
+    mysql: 110 tests ran in 1065 ms, 1 skipped, 0 failed
+    pgsql: 110 tests ran in 845 ms, 1 skipped, 0 failed
+    sqlsrv: 110 tests ran in 5404 ms, 1 skipped, 0 failed
     sqlite: skipped, driver not loaded
     ================================================
     Ubuntu 18.04 (PHP 7.2)
@@ -1316,10 +1319,10 @@ To run the docker tests run "build_all.sh" and "run_all.sh" from the docker dire
     [3/4] Starting SQLServer 2017 ... skipped
     [4/4] Cloning PHP-CRUD-API v2 ... skipped
     ------------------------------------------------
-    mysql: 110 tests ran in 3709 ms, 1 skipped, 0 failed
-    pgsql: 110 tests ran in 1334 ms, 1 skipped, 0 failed
+    mysql: 110 tests ran in 1261 ms, 1 skipped, 0 failed
+    pgsql: 110 tests ran in 859 ms, 1 skipped, 0 failed
     sqlsrv: skipped, driver not loaded
-    sqlite: 110 tests ran in 1477 ms, 12 skipped, 0 failed
+    sqlite: 110 tests ran in 725 ms, 12 skipped, 0 failed
     ================================================
     Ubuntu 20.04 (PHP 7.4)
     ================================================
@@ -1328,10 +1331,10 @@ To run the docker tests run "build_all.sh" and "run_all.sh" from the docker dire
     [3/4] Starting SQLServer 2017 ... skipped
     [4/4] Cloning PHP-CRUD-API v2 ... skipped
     ------------------------------------------------
-    mysql: 110 tests ran in 5102 ms, 1 skipped, 0 failed
-    pgsql: 110 tests ran in 1170 ms, 1 skipped, 0 failed
+    mysql: 110 tests ran in 1505 ms, 1 skipped, 0 failed
+    pgsql: 110 tests ran in 851 ms, 1 skipped, 0 failed
     sqlsrv: skipped, driver not loaded
-    sqlite: 110 tests ran in 1380 ms, 12 skipped, 0 failed
+    sqlite: 110 tests ran in 675 ms, 12 skipped, 0 failed
 
 The above test run (including starting up the databases) takes less than 5 minutes on my slow laptop.
 
@@ -1351,10 +1354,10 @@ The above test run (including starting up the databases) takes less than 5 minut
     [3/4] Starting SQLServer 2017 ... skipped
     [4/4] Cloning PHP-CRUD-API v2 ... skipped
     ------------------------------------------------
-    mysql: 105 tests ran in 3390 ms, 1 skipped, 0 failed
-    pgsql: 105 tests ran in 936 ms, 1 skipped, 0 failed
+    mysql: 110 tests ran in 1261 ms, 1 skipped, 0 failed
+    pgsql: 110 tests ran in 859 ms, 1 skipped, 0 failed
     sqlsrv: skipped, driver not loaded
-    sqlite: 105 tests ran in 1063 ms, 12 skipped, 0 failed
+    sqlite: 110 tests ran in 725 ms, 12 skipped, 0 failed
     root@b7ab9472e08f:/php-crud-api# 
 
 As you can see the "run.sh" script gives you access to a prompt in a chosen the docker environment.
diff --git a/api.include.php b/api.include.php
index 868dc65..0e866ac 100644
--- a/api.include.php
+++ b/api.include.php
@@ -6387,7 +6387,7 @@ namespace Tqdev\PhpCrudApi\Database {
             return $this->pdo()->lastInsertId($name);
         }
 
-        public function query(string $statement): \PDOStatement
+        public function query($query, /* ?int */$fetchMode = null, ...$fetchModeArgs): \PDOStatement
         {
             return call_user_func_array(array($this->pdo(), 'query'), func_get_args());
         }
@@ -7065,7 +7065,7 @@ namespace Tqdev\PhpCrudApi\Middleware\Router {
             $method = strtoupper($request->getMethod());
             $path = array();
             $segment = $method;
-            for ($i = 1; $segment; $i++) {
+            for ($i = 1; strlen($segment) > 0; $i++) {
                 array_push($path, $segment);
                 $segment = RequestUtils::getPathSegment($request, $i);
             }
@@ -7579,6 +7579,7 @@ namespace Tqdev\PhpCrudApi\Middleware {
                     $columnNames = array_map('trim', explode(',', $returnedColumns));
                     $columnNames[] = $passwordColumnName;
                     $columnNames[] = $pkName;
+                    $columnNames = array_values(array_unique($columnNames));
                 }
                 $columnOrdering = $this->ordering->getDefaultColumnOrdering($table);
                 if ($path == 'register') {
@@ -8745,7 +8746,11 @@ namespace Tqdev\PhpCrudApi\Middleware {
 
         private function xml2json($xml)
         {
-            $a = @dom_import_simplexml(simplexml_load_string($xml));
+            $o = @simplexml_load_string($xml);
+            if ($o===false) {
+                return null;
+            }
+            $a = @dom_import_simplexml($o);
             if (!$a) {
                 return null;
             }
diff --git a/api.php b/api.php
index 7d777bb..49430c7 100644
--- a/api.php
+++ b/api.php
@@ -6387,7 +6387,7 @@ namespace Tqdev\PhpCrudApi\Database {
             return $this->pdo()->lastInsertId($name);
         }
 
-        public function query(string $statement): \PDOStatement
+        public function query($query, /* ?int */$fetchMode = null, ...$fetchModeArgs): \PDOStatement
         {
             return call_user_func_array(array($this->pdo(), 'query'), func_get_args());
         }
@@ -7065,7 +7065,7 @@ namespace Tqdev\PhpCrudApi\Middleware\Router {
             $method = strtoupper($request->getMethod());
             $path = array();
             $segment = $method;
-            for ($i = 1; $segment; $i++) {
+            for ($i = 1; strlen($segment) > 0; $i++) {
                 array_push($path, $segment);
                 $segment = RequestUtils::getPathSegment($request, $i);
             }
@@ -7579,6 +7579,7 @@ namespace Tqdev\PhpCrudApi\Middleware {
                     $columnNames = array_map('trim', explode(',', $returnedColumns));
                     $columnNames[] = $passwordColumnName;
                     $columnNames[] = $pkName;
+                    $columnNames = array_values(array_unique($columnNames));
                 }
                 $columnOrdering = $this->ordering->getDefaultColumnOrdering($table);
                 if ($path == 'register') {
@@ -8745,7 +8746,11 @@ namespace Tqdev\PhpCrudApi\Middleware {
 
         private function xml2json($xml)
         {
-            $a = @dom_import_simplexml(simplexml_load_string($xml));
+            $o = @simplexml_load_string($xml);
+            if ($o===false) {
+                return null;
+            }
+            $a = @dom_import_simplexml($o);
             if (!$a) {
                 return null;
             }
diff --git a/docker-compose.yml b/docker-compose.yml
index 405da65..cc7ed6f 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -29,3 +29,5 @@ services:
         - "8080:80"
         depends_on:
         - database
+        #volumes:
+        #- .:/php-crud-api:ro
diff --git a/docker/centos8/Dockerfile b/docker/centos8/Dockerfile
index 625fdfc..59bc59e 100644
--- a/docker/centos8/Dockerfile
+++ b/docker/centos8/Dockerfile
@@ -16,10 +16,10 @@ RUN dnf -y install https://download.postgresql.org/pub/repos/yum/reporpms/EL-8-x
 # enable epel repo
 RUN dnf -y install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm
 # enable powertools repos
-RUN dnf -y install 'dnf-command(config-manager)' && dnf -y config-manager --set-enabled PowerTools
+RUN dnf -y install 'dnf-command(config-manager)' && dnf -y config-manager --set-enabled powertools
 
-# set php to remi 7.4
-RUN dnf -y module reset php && dnf -y module enable php:remi-7.4
+# set php to remi 8.0
+RUN dnf -y module reset php && dnf -y module enable php:remi-8.0
 # disable mariadb and postgresql default (appstream) repo
 RUN dnf -y module disable mariadb
 RUN dnf -y module disable postgresql
diff --git a/docker/centos8/run.sh b/docker/centos8/run.sh
index 189abe8..8dc71e4 100755
--- a/docker/centos8/run.sh
+++ b/docker/centos8/run.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 echo "================================================"
-echo " CentOS 8 (PHP 7.4)"
+echo " CentOS 8 (PHP 8.0)"
 echo "================================================"
 echo -n "[1/4] Starting MariaDB 10.5 ..... "
 # initialize mysql
diff --git a/src/Tqdev/PhpCrudApi/Database/LazyPdo.php b/src/Tqdev/PhpCrudApi/Database/LazyPdo.php
index 87c2797..b0a6c21 100644
--- a/src/Tqdev/PhpCrudApi/Database/LazyPdo.php
+++ b/src/Tqdev/PhpCrudApi/Database/LazyPdo.php
@@ -117,7 +117,7 @@ class LazyPdo extends \PDO
         return $this->pdo()->lastInsertId($name);
     }
 
-    public function query(string $statement): \PDOStatement
+    public function query($query, /* ?int */$fetchMode = null, ...$fetchModeArgs): \PDOStatement
     {
         return call_user_func_array(array($this->pdo(), 'query'), func_get_args());
     }
diff --git a/src/Tqdev/PhpCrudApi/Middleware/DbAuthMiddleware.php b/src/Tqdev/PhpCrudApi/Middleware/DbAuthMiddleware.php
index 91d4180..5e96567 100644
--- a/src/Tqdev/PhpCrudApi/Middleware/DbAuthMiddleware.php
+++ b/src/Tqdev/PhpCrudApi/Middleware/DbAuthMiddleware.php
@@ -63,6 +63,7 @@ class DbAuthMiddleware extends Middleware
                 $columnNames = array_map('trim', explode(',', $returnedColumns));
                 $columnNames[] = $passwordColumnName;
                 $columnNames[] = $pkName;
+                $columnNames = array_values(array_unique($columnNames));
             }
             $columnOrdering = $this->ordering->getDefaultColumnOrdering($table);
             if ($path == 'register') {
diff --git a/src/Tqdev/PhpCrudApi/Middleware/Router/SimpleRouter.php b/src/Tqdev/PhpCrudApi/Middleware/Router/SimpleRouter.php
index b8360ac..b1a5c75 100644
--- a/src/Tqdev/PhpCrudApi/Middleware/Router/SimpleRouter.php
+++ b/src/Tqdev/PhpCrudApi/Middleware/Router/SimpleRouter.php
@@ -104,7 +104,7 @@ class SimpleRouter implements Router
         $method = strtoupper($request->getMethod());
         $path = array();
         $segment = $method;
-        for ($i = 1; $segment; $i++) {
+        for ($i = 1; strlen($segment) > 0; $i++) {
             array_push($path, $segment);
             $segment = RequestUtils::getPathSegment($request, $i);
         }
diff --git a/src/Tqdev/PhpCrudApi/Middleware/XmlMiddleware.php b/src/Tqdev/PhpCrudApi/Middleware/XmlMiddleware.php
index b613ce1..b2225e4 100644
--- a/src/Tqdev/PhpCrudApi/Middleware/XmlMiddleware.php
+++ b/src/Tqdev/PhpCrudApi/Middleware/XmlMiddleware.php
@@ -83,7 +83,11 @@ class XmlMiddleware extends Middleware
 
     private function xml2json($xml)
     {
-        $a = @dom_import_simplexml(simplexml_load_string($xml));
+        $o = @simplexml_load_string($xml);
+        if ($o===false) {
+            return null;
+        }
+        $a = @dom_import_simplexml($o);
         if (!$a) {
             return null;
         }
diff --git a/tests/functional/001_records/003_read_post.log b/tests/functional/001_records/003_read_post.log
index 8cb9d44..86c05c6 100644
--- a/tests/functional/001_records/003_read_post.log
+++ b/tests/functional/001_records/003_read_post.log
@@ -6,3 +6,11 @@ Content-Type: application/json; charset=utf-8
 Content-Length: 58
 
 {"id":2,"user_id":1,"category_id":2,"content":"It works!"}
+===
+GET /records/posts/0
+===
+404
+Content-Type: application/json; charset=utf-8
+Content-Length: 46
+
+{"code":1003,"message":"Record '0' not found"}