diff --git a/composer.lock b/composer.lock
index c3cba04..6a56b5f 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "ef93e7890c8849fe9123c4c557e58e45",
+    "content-hash": "3449d9f432f7ba89aa4794432fe52259",
     "packages": [],
     "packages-dev": [
         {
@@ -243,6 +243,59 @@
             },
             "time": "2022-02-21T01:04:05+00:00"
         },
+        {
+            "name": "phpstan/phpstan",
+            "version": "2.1.46",
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/a193923fc2d6325ef4e741cf3af8c3e8f54dbf25",
+                "reference": "a193923fc2d6325ef4e741cf3af8c3e8f54dbf25",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.4|^8.0"
+            },
+            "conflict": {
+                "phpstan/phpstan-shim": "*"
+            },
+            "bin": [
+                "phpstan",
+                "phpstan.phar"
+            ],
+            "type": "library",
+            "autoload": {
+                "files": [
+                    "bootstrap.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "description": "PHPStan - PHP Static Analysis Tool",
+            "keywords": [
+                "dev",
+                "static analysis"
+            ],
+            "support": {
+                "docs": "https://phpstan.org/user-guide/getting-started",
+                "forum": "https://github.com/phpstan/phpstan/discussions",
+                "issues": "https://github.com/phpstan/phpstan/issues",
+                "security": "https://github.com/phpstan/phpstan/security/policy",
+                "source": "https://github.com/phpstan/phpstan-src"
+            },
+            "funding": [
+                {
+                    "url": "https://github.com/ondrejmirtes",
+                    "type": "github"
+                },
+                {
+                    "url": "https://github.com/phpstan",
+                    "type": "github"
+                }
+            ],
+            "time": "2026-04-01T09:25:14+00:00"
+        },
         {
             "name": "phpunit/php-code-coverage",
             "version": "10.1.16",
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..16f0d34
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,4 @@
+parameters:
+    paths:
+        - src
+    level: max
diff --git a/phpunit.xml b/phpunit.xml
index 9b873f6..c217093 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -3,13 +3,13 @@
          xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
          bootstrap="vendor/autoload.php"
          colors="true"
-         cacheDirectory=".phpunit.cache"
+         cacheDirectory="tests/_output/.phpunit.result.cache"
          beStrictAboutOutputDuringTests="false"
          failOnRisky="false"
          failOnWarning="true">
     <testsuites>
         <testsuite name="PHQL Test Suite">
-            <directory>tests</directory>
+            <directory>tests/unit</directory>
         </testsuite>
     </testsuites>
     <source>
@@ -19,4 +19,3 @@
         </include>
     </source>
 </phpunit>
-
diff --git a/resources/docker/develop/Dockerfile b/resources/docker/develop/Dockerfile
index 022831d..5a68a02 100644
--- a/resources/docker/develop/Dockerfile
+++ b/resources/docker/develop/Dockerfile
@@ -15,36 +15,36 @@ COPY --from=ghcr.io/php/pie:bin /pie /usr/bin/pie
 
 # Add user and group
 RUN groupadd -g "${GID}" "${GROUP}" \
-    && RUN useradd -l -m -u "${UID}" -g "${GID}" "${USER}" \
-    && RUN usermod -s /bin/bash "${USER}" \
-    && RUN mkdir /app \
-    && RUN chown "${USER}":"${GROUP}" /app \
-    && RUN chmod 0770 /app \
+    && useradd -l -m -u "${UID}" -g "${GID}" "${USER}" \
+    && usermod -s /bin/bash "${USER}" \
+    && mkdir /app \
+    && chown "${USER}":"${GROUP}" /app \
+    && chmod 0770 /app \
 # Install needed packages \
-    && RUN apt update -y \
-    && RUN apt install -yq --no-install-recommends apt-utils git locales nano sudo unzip wget zip \
+    && apt update -y \
+    && apt install -yq --no-install-recommends apt-utils git locales nano sudo unzip wget zip \
 # Configure locales \
-    && RUN sed -i -e 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen \
-    && RUN dpkg-reconfigure --frontend=noninteractive locales \
-    && RUN update-locale LANG=en_US.UTF-8 \
+    && sed -i -e 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen \
+    && dpkg-reconfigure --frontend=noninteractive locales \
+    && update-locale LANG=en_US.UTF-8 \
 # Install xdebug for code coverage \
-    && RUN apt install -yq --no-install-recommends $PHPIZE_DEPS \
-    && RUN pie install xdebug/xdebug \
-    && RUN apt-get purge -y --auto-remove $PHPIZE_DEPS \
+    && apt install -yq --no-install-recommends $PHPIZE_DEPS \
+    && pie install xdebug/xdebug \
+    && apt-get purge -y --auto-remove $PHPIZE_DEPS \
 # Copy ini file \
-    && RUN mv /usr/local/etc/php/php.ini-production /usr/local/etc/php/php.ini \
+    && mv /usr/local/etc/php/php.ini-production /usr/local/etc/php/php.ini \
 # Set correct pid file location and permissions \
-    && RUN mkdir -p /run/php \
-    && RUN chown "${USER}":"${GROUP}" /run/php \
-    && RUN chmod 0770 /run/php \
+    && mkdir -p /run/php \
+    && chown "${USER}":"${GROUP}" /run/php \
+    && chmod 0770 /run/php \
 # Cleanup \
-    && RUN apt-get autoremove --purge -y \
-    && RUN apt-get autoclean -y \
-    && RUN apt-get clean -y \
-    && RUN rm -rf /tmp/* /var/tmp/* \
-    && RUN find /var/cache/apt/archives /var/lib/apt/lists -not -name lock -type f -delete \
-    && RUN find /var/cache -type f -delete \
-    && RUN find /var/log -type f -delete \
+    && apt-get autoremove --purge -y \
+    && apt-get autoclean -y \
+    && apt-get clean -y \
+    && rm -rf /tmp/* /var/tmp/* \
+    && find /var/cache/apt/archives /var/lib/apt/lists -not -name lock -type f -delete \
+    && find /var/cache -type f -delete \
+    && find /var/log -type f -delete \
 
 COPY resources/docker/develop/.bashrc /home/${USER}/.bashrc
 COPY resources/docker/develop/extra.ini /usr/local/etc/php/conf.d/
diff --git a/tests/AbstractUnitTestCase.php b/tests/AbstractUnitTestCase.php
new file mode 100644
index 0000000..f3de57a
--- /dev/null
+++ b/tests/AbstractUnitTestCase.php
@@ -0,0 +1,19 @@
+<?php
+
+/**
+ * This file is part of the Phalcon Framework.
+ *
+ * (c) Phalcon Team <team@phalcon.io>
+ *
+ * For the full copyright and license information, please view the LICENSE.txt
+ * file that was distributed with this source code.
+ */
+declare(strict_types=1);
+
+namespace Phalcon\Phql\Tests;
+
+use PHPUnit\Framework\TestCase;
+
+abstract class AbstractUnitTestCase extends TestCase
+{
+}
diff --git a/tests/unit/Parser/PhqlParserTest.php b/tests/unit/Parser/PhqlParserTest.php
new file mode 100644
index 0000000..b7b479f
--- /dev/null
+++ b/tests/unit/Parser/PhqlParserTest.php
@@ -0,0 +1,193 @@
+<?php
+
+/**
+ * This file is part of the Phalcon Framework.
+ *
+ * (c) Phalcon Team <team@phalcon.io>
+ *
+ * For the full copyright and license information, please view the LICENSE.txt
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Phalcon\Phql\Tests\Unit\Parser;
+
+use Phalcon\Phql\Parser\Parser;
+use Phalcon\Phql\Tests\AbstractUnitTestCase;
+
+final class PhqlParserTest extends AbstractUnitTestCase
+{
+    private Parser $parser;
+
+    protected function setUp(): void
+    {
+        $this->parser = new Parser();
+    }
+
+    /**
+     * Test: Select with limit
+     * Original: tests-old/001.phpt
+     */
+    public function testSelectWithLimit(): void
+    {
+        $phql = 'SELECT r.* FROM Robots r LIMIT 10';
+        $result = $this->parser->parse($phql);
+
+        $this->assertIsArray($result);
+        $this->assertEquals(309, $result['type']);
+        $this->assertArrayHasKey('select', $result);
+        $this->assertArrayHasKey('limit', $result);
+
+        $this->assertArrayHasKey('columns', $result['select']);
+        $this->assertIsArray($result['select']['columns']);
+        $this->assertCount(1, $result['select']['columns']);
+
+        $this->assertEquals(353, $result['select']['columns'][0]['type']);
+        $this->assertEquals('r', $result['select']['columns'][0]['column']);
+
+        $this->assertArrayHasKey('tables', $result['select']);
+        $this->assertEquals('Robots', $result['select']['tables']['qualifiedName']['name']);
+        $this->assertEquals('r', $result['select']['tables']['alias']);
+
+        $this->assertEquals('10', $result['limit']['number']['value']);
+    }
+
+    /**
+     * Test: Select with BETWEEN
+     * Original: tests-old/002.phpt
+     */
+    public function testSelectWithBetween(): void
+    {
+        $phql = <<<PHQL
+SELECT column_name
+FROM table_name
+WHERE column_name BETWEEN value1 AND value2
+PHQL;
+
+        $result = $this->parser->parse($phql);
+
+        $this->assertIsArray($result);
+        $this->assertEquals(309, $result['type']);
+        $this->assertArrayHasKey('select', $result);
+        $this->assertArrayHasKey('where', $result);
+
+        $this->assertEquals('column_name', $result['select']['columns'][0]['column']['name']);
+        $this->assertEquals('table_name', $result['select']['tables']['qualifiedName']['name']);
+        $this->assertEquals('column_name', $result['where']['left']['name']);
+        $this->assertEquals('value1', $result['where']['right']['left']['name']);
+        $this->assertEquals('value2', $result['where']['right']['right']['name']);
+    }
+
+    /**
+     * Test: Using FQCN for source model
+     * Original: tests-old/003.phpt
+     */
+    public function testUsingFQCNForSourceModel(): void
+    {
+        $phql = <<<PHQL
+SELECT
+  AVG(inv_total) AS average
+FROM
+  [Phalcon\Tests\Models\Invoices]
+PHQL;
+
+        $result = $this->parser->parse($phql);
+
+        $this->assertIsArray($result);
+        $this->assertEquals(309, $result['type']);
+        $this->assertArrayHasKey('select', $result);
+
+        $this->assertEquals('AVG', $result['select']['columns'][0]['column']['name']);
+        $this->assertEquals('inv_total', $result['select']['columns'][0]['column']['arguments'][0]['name']);
+        $this->assertEquals('average', $result['select']['columns'][0]['alias']);
+
+        $this->assertEquals('[Phalcon\\Tests\\Models\\Invoices]', $result['select']['tables']['qualifiedName']['name']);
+    }
+
+    /**
+     * Test: Select with NOT BETWEEN
+     * Original: tests-old/bug14253.phpt
+     */
+    public function testSelectWithNotBetween(): void
+    {
+        $phql = <<<PHQL
+SELECT Id, ProductName, UnitPrice
+FROM Product
+WHERE UnitPrice NOT BETWEEN 5 AND 100
+PHQL;
+
+        $result = $this->parser->parse($phql);
+
+        $this->assertIsArray($result);
+        $this->assertEquals(309, $result['type']);
+        $this->assertArrayHasKey('select', $result);
+        $this->assertArrayHasKey('where', $result);
+
+        $this->assertCount(3, $result['select']['columns']);
+        $this->assertEquals('Id', $result['select']['columns'][0]['column']['name']);
+        $this->assertEquals('ProductName', $result['select']['columns'][1]['column']['name']);
+        $this->assertEquals('UnitPrice', $result['select']['columns'][2]['column']['name']);
+        $this->assertEquals('Product', $result['select']['tables']['qualifiedName']['name']);
+
+        $this->assertEquals(332, $result['where']['type']); // NOT BETWEEN type
+        $this->assertEquals('UnitPrice', $result['where']['left']['name']);
+        $this->assertEquals('5', $result['where']['right']['left']['value']);
+        $this->assertEquals('100', $result['where']['right']['right']['value']);
+    }
+
+    /**
+     * Test: Using spaces in column alias
+     * Original: tests-old/bug14535.phpt
+     */
+    public function testUsingSpacesInColumnAlias(): void
+    {
+        $phql = <<<PHQL
+SELECT
+  People.firstName AS [First Name],
+  People.lastName  AS [Last Name]
+FROM
+  People
+PHQL;
+
+        $result = $this->parser->parse($phql);
+
+        $this->assertIsArray($result);
+        $this->assertEquals(309, $result['type']);
+        $this->assertArrayHasKey('select', $result);
+
+        $this->assertCount(2, $result['select']['columns']);
+        $this->assertEquals('People', $result['select']['columns'][0]['column']['domain']);
+        $this->assertEquals('firstName', $result['select']['columns'][0]['column']['name']);
+        $this->assertEquals('[First Name]', $result['select']['columns'][0]['alias']);
+
+        $this->assertEquals('People', $result['select']['columns'][1]['column']['domain']);
+        $this->assertEquals('lastName', $result['select']['columns'][1]['column']['name']);
+        $this->assertEquals('[Last Name]', $result['select']['columns'][1]['alias']);
+
+        $this->assertEquals('People', $result['select']['tables']['qualifiedName']['name']);
+    }
+
+    /**
+     * Test: Delete with WHERE conditions using AND/OR
+     */
+    public function testDeleteWithWhereAndOr(): void
+    {
+        $phql = "DELETE FROM co_invoices "
+                . "WHERE inv_total > :test: "
+                . "AND inv_cst_id = 2 "
+                . "OR inv_status_flag = 3 ";
+
+        $parser = new Parser(true);
+        $result = $parser->parse($phql);
+
+        $this->assertIsArray($result);
+        $this->assertArrayHasKey('type', $result);
+        $this->assertArrayHasKey('delete', $result);
+
+        $this->assertArrayHasKey('tables', $result['delete']);
+        $this->assertEquals('co_invoices', $result['delete']['tables']['qualifiedName']['name']);
+
+        $this->assertArrayHasKey('where', $result);
+    }
+}
\ No newline at end of file