diff --git a/.gitignore b/.gitignore
index eed7ff6..7ce6e9b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,6 @@
 
 # PHPStorm
 **/.idea/
+
+**/.cache/
+**/.phpunit.cache/
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..3e14266
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,22 @@
+FROM composer:lts as deps
+WORKDIR /app
+RUN --mount=type=bind,source=./composer.json,target=composer.json \
+    --mount=type=bind,source=./composer.lock,target=composer.lock \
+    --mount=type=cache,target=/tmp/cache \
+    composer install --no-interaction
+
+FROM php:8-cli as base
+WORKDIR /app
+RUN apt-get update &&  \
+    apt-get install -yq --no-install-recommends libsqlite3-dev &&  \
+    rm -rf /var/lib/apt/lists/* &&  \
+    docker-php-ext-install pdo pdo_sqlite
+COPY ./src /app/src
+
+FROM base as dev
+COPY ./tests /app/tests
+RUN mv "$PHP_INI_DIR/php.ini-development" "$PHP_INI_DIR/php.ini"
+COPY --from=deps /app/vendor/ /app/vendor
+
+FROM dev as test
+ENTRYPOINT [ "./vendor/bin/phpunit" ]
diff --git a/Readme.md b/Readme.md
index f2c9f89..1cd1ae4 100644
--- a/Readme.md
+++ b/Readme.md
@@ -21,7 +21,7 @@ Database Abstraction Layer
         ...
         {
             "type": "git",
-            "path": "https://git.provm.cl/ProVM/database.git"
+            "url": "https://git.provm.cl/ProVM/database.git"
         }
         ...
     ],
diff --git a/compose.yml b/compose.yml
new file mode 100644
index 0000000..97f3091
--- /dev/null
+++ b/compose.yml
@@ -0,0 +1,5 @@
+services:
+  database:
+    build: .
+    volumes:
+      - ./:/app
diff --git a/composer.json b/composer.json
index 85a3f71..0252a19 100644
--- a/composer.json
+++ b/composer.json
@@ -1,23 +1,33 @@
 {
-    "name": "provm/database",
-    "type": "library",
-    "authors": [
-        {
-            "name": "Aldarien",
-            "email": "aldarien85@gmail.com"
-        }
-    ],
-    "require": {
-        "php": ">=8",
-        "ext-pdo": "*"
-    },
-    "require-dev": {
-        "phpunit/phpunit": "^10.0",
-        "kint-php/kint": "^5.0"
-    },
-    "autoload": {
-        "psr-4": {
-            "ProVM\\": "src/"
-        }
+  "name": "provm/database",
+  "type": "library",
+  "version": "1.2.0",
+  "authors": [
+    {
+      "name": "Aldarien",
+      "email": "aldarien85@gmail.com"
     }
+  ],
+  "require": {
+    "php": ">=8",
+    "ext-pdo": "*",
+    "provm/query_builder": "^3.0"
+  },
+  "require-dev": {
+    "phpunit/phpunit": "^10.0"
+  },
+  "autoload": {
+    "psr-4": {
+      "Database\\": "src/"
+    }
+  },
+  "config": {
+    "sort-packages": true
+  },
+  "repositories": [
+    {
+      "type": "vcs",
+      "url": "https://git.provm.cl/ProVM/query_builder.git"
+    }
+  ]
 }
diff --git a/phpunit.xml b/phpunit.xml
new file mode 100644
index 0000000..d19d6d9
--- /dev/null
+++ b/phpunit.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.5/phpunit.xsd"
+         bootstrap="vendor/autoload.php"
+         cacheDirectory=".phpunit.cache"
+         executionOrder="depends,defects"
+         requireCoverageMetadata="false"
+         beStrictAboutCoverageMetadata="true"
+         beStrictAboutOutputDuringTests="true"
+         displayDetailsOnPhpunitDeprecations="true"
+         colors="true"
+         failOnPhpunitDeprecation="true"
+         failOnRisky="true"
+         failOnWarning="true">
+    <testsuites>
+        <testsuite name="default">
+            <directory>tests</directory>
+        </testsuite>
+    </testsuites>
+
+    <source restrictDeprecations="true" restrictNotices="true" restrictWarnings="true">
+        <include>
+            <directory>src</directory>
+        </include>
+    </source>
+</phpunit>
diff --git a/src/Concept/Database/Connection.php b/src/Concept/Database/Connection.php
deleted file mode 100644
index 705400d..0000000
--- a/src/Concept/Database/Connection.php
+++ /dev/null
@@ -1,15 +0,0 @@
-<?php
-namespace ProVM\Concept\Database;
-
-use ProVM\Concept\Database;
-
-interface Connection
-{
-    public function connect(): \PDO;
-
-    public function transaction(): Transaction;
-
-    public function query(string $query): ResultSet;
-    public function prepare(string $query): ResultSet;
-    public function execute(string $query, ?array $data = null): ResultSet;
-}
diff --git a/src/Database/Connection.php b/src/Database/Connection.php
deleted file mode 100644
index 934eba4..0000000
--- a/src/Database/Connection.php
+++ /dev/null
@@ -1,68 +0,0 @@
-<?php
-namespace ProVM\Database;
-
-use PDO;
-use ProVM\Concept\Database;
-
-class Connection implements Database\Connection
-{
-    public function __construct(Database $database)
-    {
-        $this->setDatabase($database);
-    }
-
-    protected Database $database;
-
-    protected function getDatabase(): Database
-    {
-        return $this->database;
-    }
-
-    protected function setDatabase(Database $database): Database\Connection
-    {
-        $this->database = $database;
-        return $this;
-    }
-
-    protected PDO $pdo;
-    public function connect(): PDO
-    {
-        if (!isset($this->pdo)) {
-            $dsn = $this->getDatabase()->getDsn();
-            if ($this->getDatabase()->needsUser()) {
-                $this->pdo = new PDO($dsn, $this->getDatabase()->getUser(), $this->getDatabase()->getPassword());
-            } else {
-                $this->pdo = new PDO($dsn);
-            }
-        }
-        return $this->pdo;
-    }
-
-    protected Database\Transaction $transaction;
-
-    public function transaction(): Database\Transaction
-    {
-        if (!isset($this->transaction)) {
-            $this->transaction = new Transaction($this);
-        }
-        return $this->transaction;
-    }
-
-    public function query(string $query): Database\ResultSet
-    {
-        return new ResultSet($this->connect()->query($query));
-    }
-    public function prepare(string $query): Database\ResultSet
-    {
-        return new ResultSet($this->connect()->prepare($query));
-    }
-    public function execute(string $query, ?array $data = null): Database\ResultSet
-    {
-        if ($data !== null) {
-            $rs = $this->prepare($query);
-            $rs->execute($data);
-            return $rs;
-        }
-        return $this->query($query);
-    }
-}
diff --git a/src/Database/Transaction.php b/src/Database/Transaction.php
deleted file mode 100644
index 3181903..0000000
--- a/src/Database/Transaction.php
+++ /dev/null
@@ -1,40 +0,0 @@
-<?php
-namespace ProVM\Database;
-
-use PDO;
-use ProVM\Concept;
-
-class Transaction implements Concept\Database\Transaction
-{
-    public function __construct(Concept\Database\Connection $connection)
-    {
-        $this->setConnection($connection);
-    }
-
-    protected Concept\Database\Connection $connection;
-
-    public function getConnection(): Concept\Database\Connection
-    {
-        return $this->connection;
-    }
-
-    public function setConnection(Concept\Database\Connection $connection): Concept\Database\Transaction
-    {
-        $this->connection = $connection;
-        return $this;
-    }
-
-    public function begin(): Concept\Database\Transaction
-    {
-        $this->getConnection()->connect()->beginTransaction();
-        return $this;
-    }
-    public function commit(): void
-    {
-        $this->getConnection()->connect()->commit();
-    }
-    public function rollBack(): void
-    {
-        $this->getConnection()->connect()->rollBack();
-    }
-}
diff --git a/src/Concept/Database.php b/src/Define/Database.php
similarity index 50%
rename from src/Concept/Database.php
rename to src/Define/Database.php
index bc9f2a9..75f9804 100644
--- a/src/Concept/Database.php
+++ b/src/Define/Database.php
@@ -1,5 +1,5 @@
 <?php
-namespace ProVM\Concept;
+namespace Database\Define;
 
 interface Database
 {
@@ -9,10 +9,10 @@ interface Database
     public function getUser(): string;
     public function getPassword(): string;
     public function needsUser(): bool;
-    public function setHost(string $host): Database;
-    public function setPort(int $port): Database;
-    public function setName(string $name): Database;
-    public function setUser(string $username): Database;
-    public function setPassword(string $password): Database;
+    public function setHost(string $host): self;
+    public function setPort(int $port): self;
+    public function setName(string $name): self;
+    public function setUser(string $username): self;
+    public function setPassword(string $password): self;
     public function getDsn(): string;
 }
diff --git a/src/Define/Database/Connection.php b/src/Define/Database/Connection.php
new file mode 100644
index 0000000..829c43a
--- /dev/null
+++ b/src/Define/Database/Connection.php
@@ -0,0 +1,43 @@
+<?php
+namespace Database\Define\Database;
+
+use PDO;
+use PDOException;
+use Database\Define\Query\Builder;
+use Database\Exception\Database\InvalidQuery;
+
+interface Connection
+{
+    /**
+     * @return self
+     * @throws PDOException
+     */
+    public function connect(): self;
+    public function getPDO(): PDO;
+
+    public function queryBuilder(): Builder;
+
+    public function transaction(): Transaction;
+
+    /**
+     * @param string $query
+     * @return ResultSet
+     * @throws InvalidQuery
+     */
+    public function query(string $query): ResultSet;
+
+    /**
+     * @param string $query
+     * @return ResultSet
+     * @throws InvalidQuery
+     */
+    public function prepare(string $query): ResultSet;
+
+    /**
+     * @param string $query
+     * @param array|null $data
+     * @return ResultSet
+     * @throws InvalidQuery
+     */
+    public function execute(string $query, ?array $data = null): ResultSet;
+}
diff --git a/src/Concept/Database/ResultSet.php b/src/Define/Database/ResultSet.php
similarity index 57%
rename from src/Concept/Database/ResultSet.php
rename to src/Define/Database/ResultSet.php
index 4c744b2..d223897 100644
--- a/src/Concept/Database/ResultSet.php
+++ b/src/Define/Database/ResultSet.php
@@ -1,9 +1,12 @@
 <?php
-namespace ProVM\Concept\Database;
+namespace Database\Define\Database;
+
+use PDOStatement;
 
 interface ResultSet
 {
-    public function execute(array $data): ResultSet;
+    public function getStatement(): PDOStatement;
+    public function execute(array $data): self;
 
     public function fetchFirst(): array;
     public function fetchAll(): array;
diff --git a/src/Concept/Database/Transaction.php b/src/Define/Database/Transaction.php
similarity index 80%
rename from src/Concept/Database/Transaction.php
rename to src/Define/Database/Transaction.php
index bd76772..a7f50ad 100644
--- a/src/Concept/Database/Transaction.php
+++ b/src/Define/Database/Transaction.php
@@ -1,5 +1,5 @@
 <?php
-namespace ProVM\Concept\Database;
+namespace Database\Define\Database;
 
 interface Transaction
 {
diff --git a/src/Exception/Database.php b/src/Exception/Database.php
index d1a2759..1d463a0 100644
--- a/src/Exception/Database.php
+++ b/src/Exception/Database.php
@@ -1,12 +1,12 @@
 <?php
-namespace ProVM\Exception;
+namespace Database\Exception;
 
 use Exception;
 use Throwable;
 
 abstract class Database extends Exception
 {
-    const BASE_CODE = 600;
+    const BASE_CODE = 1000;
 
     public function __construct(string $message = "", int $code = 0, ?Throwable $previous = null)
     {
diff --git a/src/Exception/Database/BlankResult.php b/src/Exception/Database/BlankResult.php
index 9a2294d..0119442 100644
--- a/src/Exception/Database/BlankResult.php
+++ b/src/Exception/Database/BlankResult.php
@@ -1,8 +1,8 @@
 <?php
-namespace ProVM\Exception\Database;
+namespace Database\Exception\Database;
 
 use Throwable;
-use ProVM\Exception\Database;
+use Database\Exception\Database;
 
 class BlankResult extends Database
 {
diff --git a/src/Exception/Database/InvalidQuery.php b/src/Exception/Database/InvalidQuery.php
new file mode 100644
index 0000000..4094631
--- /dev/null
+++ b/src/Exception/Database/InvalidQuery.php
@@ -0,0 +1,14 @@
+<?php
+namespace Database\Exception\Database;
+
+use Throwable;
+use Database\Exception;
+
+class InvalidQuery extends Exception\Database
+{
+    public function __construct(string $query, ?Throwable $previous = null)
+    {
+        $message = "Invalid query \"{$query}\"";
+        parent::__construct($message, 0, $previous);
+    }
+}
diff --git a/src/Implement/Database.php b/src/Ideal/Database.php
similarity index 70%
rename from src/Implement/Database.php
rename to src/Ideal/Database.php
index 4093c19..344e8c6 100644
--- a/src/Implement/Database.php
+++ b/src/Ideal/Database.php
@@ -1,9 +1,9 @@
 <?php
-namespace ProVM\Implement;
+namespace Database\Ideal;
 
-use ProVM\Concept;
+use Database\Define;
 
-abstract class Database implements Concept\Database
+abstract class Database implements Define\Database
 {
     protected string $host;
     protected int $port;
@@ -32,27 +32,27 @@ abstract class Database implements Concept\Database
         return $this->password;
     }
 
-    public function setHost(string $host): Concept\Database
+    public function setHost(string $host): Define\Database
     {
         $this->host = $host;
         return $this;
     }
-    public function setPort(int $port): Concept\Database
+    public function setPort(int $port): Define\Database
     {
         $this->port = $port;
         return $this;
     }
-    public function setName(string $name): Concept\Database
+    public function setName(string $name): Define\Database
     {
         $this->name = $name;
         return $this;
     }
-    public function setUser(string $username): Concept\Database
+    public function setUser(string $username): Define\Database
     {
         $this->user = $username;
         return $this;
     }
-    public function setPassword(string $password): Concept\Database
+    public function setPassword(string $password): Define\Database
     {
         $this->password = $password;
         return $this;
diff --git a/src/Implement/Connection.php b/src/Implement/Connection.php
new file mode 100644
index 0000000..959269b
--- /dev/null
+++ b/src/Implement/Connection.php
@@ -0,0 +1,121 @@
+<?php
+namespace Database\Implement;
+
+use PDO;
+use PDOException;
+use Database\Define;
+use Database\Exception\Database\InvalidQuery;
+
+class Connection implements Define\Database\Connection
+{
+    public function __construct(Define\Database $database)
+    {
+        $this->setDatabase($database);
+    }
+
+    protected Define\Database $database;
+
+    protected function getDatabase(): Define\Database
+    {
+        return $this->database;
+    }
+
+    protected function setDatabase(Define\Database $database): self
+    {
+        $this->database = $database;
+        return $this;
+    }
+    protected Define\Query\Builder $builder;
+    public function queryBuilder(): Define\Query\Builder
+    {
+        return $this->builder;
+    }
+    public function setBuilder(Define\Query\Builder $builder): self
+    {
+        $this->builder = $builder;
+        return $this;
+    }
+
+    protected PDO $pdo;
+    public function connect(): self
+    {
+        if (!isset($this->pdo)) {
+            $dsn = $this->getDatabase()->getDsn();
+            if ($this->getDatabase()->needsUser()) {
+                $this->pdo = new PDO($dsn, $this->getDatabase()->getUser(), $this->getDatabase()->getPassword());
+            } else {
+                $this->pdo = new PDO($dsn);
+            }
+        }
+        return $this;
+    }
+    public function getPDO(): PDO
+    {
+        return $this->connect()->pdo;
+    }
+
+    protected Define\Database\Transaction $transaction;
+
+    public function transaction(): Define\Database\Transaction
+    {
+        if (!isset($this->transaction)) {
+            $this->transaction = new Transaction($this);
+        }
+        return $this->transaction;
+    }
+
+    public function query(string $query): Define\Database\ResultSet
+    {
+        try {
+            $statement = $this->getPDO()->query($query);
+        } catch (PDOException $exception) {
+            throw new InvalidQuery($query, $exception);
+        }
+        if ($statement === false) {
+            throw new InvalidQuery($query);
+        }
+        return new ResultSet($statement);
+    }
+    public function prepare(string $query): Define\Database\ResultSet
+    {
+        try {
+            $statement = $this->getPDO()->prepare($query);
+        } catch (PDOException $exception) {
+            throw new InvalidQuery($query, $exception);
+        }
+        if ($statement === false) {
+            throw new InvalidQuery($query);
+        }
+        return new ResultSet($statement);
+    }
+    public function execute(string $query, ?array $data = null): Define\Database\ResultSet
+    {
+        if ($data !== null) {
+            return $this->prepare($query)
+                ->execute($data);
+        }
+        return $this->query($query);
+    }
+
+    /**
+     * @param string $query
+     * @param array|null $data
+     * @return array
+     * @throws InvalidQuery
+     */
+    public function fetchOne(string $query, ?array $data = null): array
+    {
+        return $this->execute($query, $data)->fetchFirst();
+    }
+
+    /**
+     * @param string $query
+     * @param array|null $data
+     * @return array
+     * @throws InvalidQuery
+     */
+    public function fetchMany(string $query, ?array $data = null): array
+    {
+        return $this->execute($query, $data)->fetchAll();
+    }
+}
diff --git a/src/Database/MySQL.php b/src/Implement/MySQL.php
similarity index 86%
rename from src/Database/MySQL.php
rename to src/Implement/MySQL.php
index a4e009f..546366c 100644
--- a/src/Database/MySQL.php
+++ b/src/Implement/MySQL.php
@@ -1,7 +1,7 @@
 <?php
-namespace ProVM\Database;
+namespace Database\Implement;
 
-use ProVM\Implement\Database;
+use Database\Ideal\Database;
 
 class MySQL extends Database
 {
diff --git a/src/Database/PostgreSQL.php b/src/Implement/PostgreSQL.php
similarity index 87%
rename from src/Database/PostgreSQL.php
rename to src/Implement/PostgreSQL.php
index fc83fe6..6fb4a8d 100644
--- a/src/Database/PostgreSQL.php
+++ b/src/Implement/PostgreSQL.php
@@ -1,7 +1,7 @@
 <?php
-namespace ProVM\Database;
+namespace Database\Implement;
 
-use ProVM\Implement\Database;
+use Database\Ideal\Database;
 
 class PostgreSQL extends Database
 {
diff --git a/src/Database/ResultSet.php b/src/Implement/ResultSet.php
similarity index 63%
rename from src/Database/ResultSet.php
rename to src/Implement/ResultSet.php
index d357ffc..b951cf1 100644
--- a/src/Database/ResultSet.php
+++ b/src/Implement/ResultSet.php
@@ -1,12 +1,12 @@
 <?php
-namespace ProVM\Database;
+namespace Database\Implement;
 
 use PDO;
 use PDOStatement;
-use ProVM\Concept\Database;
-use ProVM\Exception\Database\BlankResult;
+use Database\Define;
+use Database\Exception\Database\BlankResult;
 
-class ResultSet implements Database\ResultSet
+class ResultSet implements Define\Database\ResultSet
 {
     public function __construct(PDOStatement $statement)
     {
@@ -15,22 +15,26 @@ class ResultSet implements Database\ResultSet
 
     protected PDOStatement $statement;
 
-    protected function getStatement(): PDOStatement
+    public function getStatement(): PDOStatement
     {
         return $this->statement;
     }
-    protected function setStatement(PDOStatement $statement): ResultSet
+    protected function setStatement(PDOStatement $statement): self
     {
         $this->statement = $statement;
         return $this;
     }
 
-    public function execute(array $data): Database\ResultSet
+    public function execute(array $data): self
     {
         $this->statement->execute($data);
         return $this;
     }
 
+    /**
+     * @return PDOStatement
+     * @throws BlankResult
+     */
     protected function checkResults(): PDOStatement
     {
         if ($this->getStatement()->rowCount() === 0) {
@@ -38,18 +42,38 @@ class ResultSet implements Database\ResultSet
         }
         return $this->getStatement();
     }
+
+    /**
+     * @return array
+     * @throws BlankResult
+     */
     public function fetchFirst(): array
     {
         return $this->checkResults()->fetch(PDO::FETCH_ASSOC);
     }
+
+    /**
+     * @return array
+     * @throws BlankResult
+     */
     public function fetchAll(): array
     {
         return $this->checkResults()->fetchAll(PDO::FETCH_ASSOC);
     }
+
+    /**
+     * @return object
+     * @throws BlankResult
+     */
     public function fetchFirstAsObject(): object
     {
         return $this->checkResults()->fetch(PDO::FETCH_OBJ);
     }
+
+    /**
+     * @return array
+     * @throws BlankResult
+     */
     public function fetchAllAsObjects(): array
     {
         return $this->checkResults()->fetchAll(PDO::FETCH_OBJ);
diff --git a/src/Database/SQLite.php b/src/Implement/SQLite.php
similarity index 69%
rename from src/Database/SQLite.php
rename to src/Implement/SQLite.php
index f8ab299..e43481c 100644
--- a/src/Database/SQLite.php
+++ b/src/Implement/SQLite.php
@@ -1,7 +1,7 @@
 <?php
-namespace ProVM\Database;
+namespace Database\Implement;
 
-use ProVM\Implement\Database;
+use Database\Ideal\Database;
 
 class SQLite extends Database
 {
diff --git a/src/Implement/Transaction.php b/src/Implement/Transaction.php
new file mode 100644
index 0000000..a51621e
--- /dev/null
+++ b/src/Implement/Transaction.php
@@ -0,0 +1,39 @@
+<?php
+namespace Database\Implement;
+
+use Database\Define;
+
+class Transaction implements Define\Database\Transaction
+{
+    public function __construct(Define\Database\Connection $connection)
+    {
+        $this->setConnection($connection);
+    }
+
+    protected Define\Database\Connection $connection;
+
+    public function getConnection(): Define\Database\Connection
+    {
+        return $this->connection;
+    }
+
+    public function setConnection(Define\Database\Connection $connection): self
+    {
+        $this->connection = $connection;
+        return $this;
+    }
+
+    public function begin(): self
+    {
+        $this->getConnection()->getPDO()->beginTransaction();
+        return $this;
+    }
+    public function commit(): void
+    {
+        $this->getConnection()->getPDO()->commit();
+    }
+    public function rollBack(): void
+    {
+        $this->getConnection()->getPDO()->rollBack();
+    }
+}
diff --git a/tests/ConnectionTest.php b/tests/ConnectionTest.php
new file mode 100644
index 0000000..9286f22
--- /dev/null
+++ b/tests/ConnectionTest.php
@@ -0,0 +1,61 @@
+<?php
+use PHPUnit\Framework\TestCase;
+
+use Database\Implement\Connection;
+use Database\Define;
+
+class ConnectionTest extends TestCase
+{
+    protected string $host = '/tmp/test.db3';
+    protected string $tableName = 'test_table';
+    protected PDO $pdo;
+    protected function setUp(): void
+    {
+        $this->pdo = new PDO("sqlite:{$this->host}");
+        $query = "CREATE TABLE IF NOT EXISTS {$this->tableName} (id INTEGER PRIMARY KEY, test TEXT)";
+        $this->pdo->query($query);
+        $query = "INSERT INTO {$this->tableName} (test) VALUES ('test')";
+        $this->pdo->query($query);
+    }
+    protected function tearDown(): void
+    {
+        unset($this->pdo);
+        unlink($this->host);
+    }
+
+    protected function getConnection(): Connection
+    {
+        $host = $this->host;
+
+        $database = $this->getMockBuilder(Define\Database::class)->getMock();
+        $database->method('getHost')->willReturn($host);
+        $database->method('getDsn')->willReturn("sqlite:{$host}");
+        $database->method('needsUser')->willReturn(false);
+
+        return new Connection($database);
+    }
+
+    public function testConnection()
+    {
+        $connection = $this->getConnection();
+        $this->assertEquals($this->pdo, $connection->getPDO());
+    }
+    public function testQuery()
+    {
+        $connection = $this->getConnection();
+        $query = "CREATE TABLE IF NOT EXISTS test_table (id INTEGER PRIMARY KEY, test TEXT)";
+        $connection->query($query);
+        $query = "SELECT * FROM test_table";
+        $connection->query($query);
+        $this->assertTrue(true);
+    }
+    public function testPrepare()
+    {
+        $connection = $this->getConnection();
+        $query = "CREATE TABLE IF NOT EXISTS test_table (id INTEGER PRIMARY KEY, test TEXT)";
+        $connection->query($query);
+        $query = "SELECT * FROM test_table";
+        $connection->prepare($query);
+        $this->assertTrue(true);
+    }
+}
diff --git a/tests/MySQLTest.php b/tests/MySQLTest.php
new file mode 100644
index 0000000..cce4c82
--- /dev/null
+++ b/tests/MySQLTest.php
@@ -0,0 +1,32 @@
+<?php
+use PHPUnit\Framework\TestCase;
+use Database\Implement\MySQL;
+
+class MySQLTest extends TestCase
+{
+    public function testDatabase()
+    {
+        $host = "testhost";
+        $port = 1234;
+        $name = "testdb";
+        $user = "testuser";
+        $pass = "testpass";
+
+        $dsn = "mysql:host={$host};port={$port};dbname={$name}";
+
+        $database = new MySQL();
+        $database->setHost($host);
+        $database->setPort($port);
+        $database->setName($name);
+        $database->setUser($user);
+        $database->setPassword($pass);
+
+        $this->assertEquals($host, $database->getHost());
+        $this->assertEquals($port, $database->getPort());
+        $this->assertEquals($name, $database->getName());
+        $this->assertEquals($user, $database->getUser());
+        $this->assertEquals($pass, $database->getPassword());
+        $this->assertTrue($database->needsUser());
+        $this->assertEquals($dsn, $database->getDsn());
+    }
+}
diff --git a/tests/PostgreSQLTest.php b/tests/PostgreSQLTest.php
new file mode 100644
index 0000000..21b26c3
--- /dev/null
+++ b/tests/PostgreSQLTest.php
@@ -0,0 +1,32 @@
+<?php
+use PHPUnit\Framework\TestCase;
+use Database\Implement\PostgreSQL;
+
+class PostgreSQLTest extends TestCase
+{
+    public function testDatabase()
+    {
+        $host = "testhost";
+        $port = 1234;
+        $name = "testdb";
+        $user = "testuser";
+        $pass = "testpass";
+
+        $dsn = "pgsql:host={$host};port={$port};dbname={$name};user={$user};password={$pass}";
+
+        $database = new PostgreSQL();
+        $database->setHost($host);
+        $database->setPort($port);
+        $database->setName($name);
+        $database->setUser($user);
+        $database->setPassword($pass);
+
+        $this->assertEquals($host, $database->getHost());
+        $this->assertEquals($port, $database->getPort());
+        $this->assertEquals($name, $database->getName());
+        $this->assertEquals($user, $database->getUser());
+        $this->assertEquals($pass, $database->getPassword());
+        $this->assertFalse($database->needsUser());
+        $this->assertEquals($dsn, $database->getDsn());
+    }
+}
diff --git a/tests/ResultSetTest.php b/tests/ResultSetTest.php
new file mode 100644
index 0000000..a01c98a
--- /dev/null
+++ b/tests/ResultSetTest.php
@@ -0,0 +1,26 @@
+<?php
+use PHPUnit\Framework\TestCase;
+
+use Database\Implement\ResultSet;
+
+class ResultSetTest extends TestCase
+{
+    public function testResultSet()
+    {
+        $result1 = ['col1', 'col2', 'col3'];
+        $result2 = [['col1', 'col2'], ['col3', 'col4']];
+
+        $statement = $this->getMockBuilder(PDOStatement::class)->getMock();
+        $statement->method('execute')->willReturn(true);
+        $statement->method('fetch')->willReturn($result1);
+        $statement->method('fetchAll')->willReturn($result2);
+        $statement->method('rowCount')->willReturn(2);
+
+        $resultSet = new ResultSet($statement);
+
+        $resultSet->execute(['foo' => 'bar']);
+        $this->assertTrue(true);
+        $this->assertEquals($result1, $resultSet->fetchFirst());
+        $this->assertEquals($result2, $resultSet->fetchAll());
+    }
+}
diff --git a/tests/SQLiteTest.php b/tests/SQLiteTest.php
new file mode 100644
index 0000000..f4f5cb6
--- /dev/null
+++ b/tests/SQLiteTest.php
@@ -0,0 +1,20 @@
+<?php
+use PHPUnit\Framework\TestCase;
+use Database\Implement\SQLite;
+
+class SQLiteTest extends TestCase
+{
+    public function testDatabase()
+    {
+        $host = ":memory:";
+
+        $dsn = "sqlite:{$host}";
+
+        $database = new SQLite();
+        $database->setHost($host);
+
+        $this->assertEquals($host, $database->getHost());
+        $this->assertFalse($database->needsUser());
+        $this->assertEquals($dsn, $database->getDsn());
+    }
+}
diff --git a/tests/TransactionTest.php b/tests/TransactionTest.php
new file mode 100644
index 0000000..e5265bd
--- /dev/null
+++ b/tests/TransactionTest.php
@@ -0,0 +1,19 @@
+<?php
+use PHPUnit\Framework\TestCase;
+use Database\Implement\Transaction;
+
+class TransactionTest extends TestCase
+{
+    public function testTransaction()
+    {
+        $connection = $this->createMock(Database\Define\Database\Connection::class);
+        $transaction = new Transaction($connection);
+        $transaction->begin();
+        $this->assertTrue(true);
+        $transaction->commit();
+        $this->assertTrue(true);
+        $transaction->begin();
+        $transaction->rollback();
+        $this->assertTrue(true);
+    }
+}