From 232c7c5d7eebf04c91568d4c2067ac4124c9e721 Mon Sep 17 00:00:00 2001
From: Pierre Rineau <pierre.rineau@makina-corpus.com>
Date: Mon, 26 Feb 2024 12:30:12 +0100
Subject: [PATCH] no issue - error handling

---
 docs/.vitepress/config.mts                    |   1 +
 src/Bridge/AbstractBridge.php                 |  49 +-
 src/Bridge/Bridge.php                         |   5 +
 src/Bridge/Doctrine/DoctrineQueryBuilder.php  |  12 +-
 .../ErrorConverter/DoctrineErrorConverter.php |  95 ++++
 src/Bridge/ErrorConverter.php                 |  20 +
 src/Bridge/PassthroughErrorConverter.php      |  23 +
 .../ErrorConverter/PdoMySQLErrorConverter.php | 129 +++++
 .../PdoPostgreSQLErrorConverter.php           | 109 ++++
 .../PdoSQLServerErrorConverter.php            |  69 +++
 .../PdoSQLiteErrorConverter.php               | 114 ++++
 src/Bridge/Pdo/PdoQueryBuilder.php            |  25 +-
 src/Error/Bridge/AmbiguousIdentifierError.php |   9 +
 src/Error/Bridge/ColumnDoesNotExistError.php  |   9 +
 src/Error/Bridge/ConstraintViolationError.php |   9 +
 .../DatabaseObjectDoesNotExistError.php       |   9 +
 .../ForeignKeyConstraintViolationError.php    |   9 +
 .../NotNullConstraintViolationError.php       |   9 +
 src/Error/Bridge/ServerError.php              |   9 +
 src/Error/Bridge/TableDoesNotExistError.php   |   9 +
 src/Error/Bridge/TransactionDeadlockError.php |   9 +
 src/Error/Bridge/TransactionError.php         |   9 +
 src/Error/Bridge/TransactionFailedError.php   |   9 +
 .../TransactionLockWaitTimeoutError.php       |   9 +
 src/Error/Bridge/UnableToConnectError.php     |   9 +
 .../Bridge/UniqueConstraintViolationError.php |   9 +
 src/QueryExecutor.php                         |   2 +
 .../Bridge/AbstractErrorConverterTestCase.php | 316 +++++++++++
 .../Doctrine/DoctrineErrorConverterTest.php   |  13 +
 tests/Bridge/Pdo/PdoErrorConverterTest.php    |  13 +
 .../Functional/TransactionFunctionalTest.php  | 491 ++++++++++++++++++
 31 files changed, 1607 insertions(+), 5 deletions(-)
 create mode 100644 src/Bridge/Doctrine/ErrorConverter/DoctrineErrorConverter.php
 create mode 100644 src/Bridge/ErrorConverter.php
 create mode 100644 src/Bridge/PassthroughErrorConverter.php
 create mode 100644 src/Bridge/Pdo/ErrorConverter/PdoMySQLErrorConverter.php
 create mode 100644 src/Bridge/Pdo/ErrorConverter/PdoPostgreSQLErrorConverter.php
 create mode 100644 src/Bridge/Pdo/ErrorConverter/PdoSQLServerErrorConverter.php
 create mode 100644 src/Bridge/Pdo/ErrorConverter/PdoSQLiteErrorConverter.php
 create mode 100644 src/Error/Bridge/AmbiguousIdentifierError.php
 create mode 100644 src/Error/Bridge/ColumnDoesNotExistError.php
 create mode 100644 src/Error/Bridge/ConstraintViolationError.php
 create mode 100644 src/Error/Bridge/DatabaseObjectDoesNotExistError.php
 create mode 100644 src/Error/Bridge/ForeignKeyConstraintViolationError.php
 create mode 100644 src/Error/Bridge/NotNullConstraintViolationError.php
 create mode 100644 src/Error/Bridge/ServerError.php
 create mode 100644 src/Error/Bridge/TableDoesNotExistError.php
 create mode 100644 src/Error/Bridge/TransactionDeadlockError.php
 create mode 100644 src/Error/Bridge/TransactionError.php
 create mode 100644 src/Error/Bridge/TransactionFailedError.php
 create mode 100644 src/Error/Bridge/TransactionLockWaitTimeoutError.php
 create mode 100644 src/Error/Bridge/UnableToConnectError.php
 create mode 100644 src/Error/Bridge/UniqueConstraintViolationError.php
 create mode 100644 tests/Bridge/AbstractErrorConverterTestCase.php
 create mode 100644 tests/Bridge/Doctrine/DoctrineErrorConverterTest.php
 create mode 100644 tests/Bridge/Pdo/PdoErrorConverterTest.php
 create mode 100644 tests/Functional/TransactionFunctionalTest.php

diff --git a/docs/.vitepress/config.mts b/docs/.vitepress/config.mts
index 9b2468f..62da096 100644
--- a/docs/.vitepress/config.mts
+++ b/docs/.vitepress/config.mts
@@ -55,6 +55,7 @@ export default defineConfig({
               { text: 'Doctrine DBAL setup', link: '/introduction/getting-started#doctrine-dbal-setup' },
               { text: 'PDO setup', link: '/introduction/getting-started#pdo-setup' },
               { text: 'Symfony setup', link: '/introduction/getting-started#symfony-setup' },
+              { text: 'Error handling', link: '/bridges/error' },
             ]
           },
           { text: 'Samples usages', link: '/introduction/usage' },
diff --git a/src/Bridge/AbstractBridge.php b/src/Bridge/AbstractBridge.php
index 27c7306..6ce5500 100644
--- a/src/Bridge/AbstractBridge.php
+++ b/src/Bridge/AbstractBridge.php
@@ -34,6 +34,7 @@ abstract class AbstractBridge extends DefaultQueryBuilder implements Bridge
     private ?string $serverVersion = null;
     private bool $serverVersionLookekUp = false;
     private ?string $serverFlavor = null;
+    private ?ErrorConverter $errorConverter = null;
 
     public function __construct(?ConverterPluginRegistry $converterPluginRegistry = null)
     {
@@ -41,6 +42,17 @@ public function __construct(?ConverterPluginRegistry $converterPluginRegistry =
         $this->setQueryExecutor($this);
     }
 
+    /**
+     * Disable error converter. Must be called prior to initilization.
+     */
+    public function disableErrorConverter(): bool
+    {
+        if ($this->errorConverter) {
+            throw new QueryBuilderError("Bridge is already initialized, configuration must happend before it gets used.");
+        }
+        $this->errorConverter = new PassthroughErrorConverter();
+    }
+
     /**
      * @internal
      *   For dependency injection only.
@@ -82,6 +94,31 @@ public function getServerName(): ?string
         return $this->serverName;
     }
 
+    /**
+     * Get error converter.
+     */
+    protected function getErrorConverter(): ErrorConverter
+    {
+        return $this->errorConverter ??= $this->createErrorConverter();
+    }
+
+    /**
+     * @internal
+     *    For dependency injection only.
+     */
+    public function setErrorConverter(ErrorConverter $errorConverter): void
+    {
+        $this->errorConverter = $errorConverter;
+    }
+
+    /**
+     * Please override.
+     */
+    protected function createErrorConverter(): ErrorConverter
+    {
+        return new PassthroughErrorConverter();
+    }
+
     /**
      * Please override.
      */
@@ -199,7 +236,11 @@ public function executeQuery(string|Expression $expression = null, mixed $argume
 
         $prepared = $this->getWriter()->prepare($expression);
 
-        return $this->doExecuteQuery($prepared->toString(), $prepared->getArguments()->getAll());
+        try {
+            return $this->doExecuteQuery($prepared->toString(), $prepared->getArguments()->getAll());
+        } catch (\Throwable $e) {
+            throw $this->getErrorConverter()->convertError($e);
+        }
     }
 
     /**
@@ -223,7 +264,11 @@ public function executeStatement(string|Expression $expression = null, mixed $ar
 
         $prepared = $this->getWriter()->prepare($expression);
 
-        return $this->doExecuteStatement($prepared->toString(), $prepared->getArguments()->getAll());
+        try {
+            return $this->doExecuteStatement($prepared->toString(), $prepared->getArguments()->getAll());
+        } catch (\Throwable $e) {
+            throw $this->getErrorConverter()->convertError($e);
+        }
     }
 
     /**
diff --git a/src/Bridge/Bridge.php b/src/Bridge/Bridge.php
index 3a6b888..6c55310 100644
--- a/src/Bridge/Bridge.php
+++ b/src/Bridge/Bridge.php
@@ -10,6 +10,11 @@
 
 interface Bridge extends QueryExecutor, QueryBuilder
 {
+    /**
+     * Disable error converter. Must be called prior to initilization.
+     */
+    public function disableErrorConverter(): bool;
+
     /**
      * Get server name.
      */
diff --git a/src/Bridge/Doctrine/DoctrineQueryBuilder.php b/src/Bridge/Doctrine/DoctrineQueryBuilder.php
index d7ea09b..59ac253 100644
--- a/src/Bridge/Doctrine/DoctrineQueryBuilder.php
+++ b/src/Bridge/Doctrine/DoctrineQueryBuilder.php
@@ -6,13 +6,15 @@
 
 use Doctrine\DBAL\Connection;
 use Doctrine\DBAL\Driver\ServerInfoAwareConnection;
-use MakinaCorpus\QueryBuilder\Platform;
 use MakinaCorpus\QueryBuilder\Bridge\AbstractBridge;
+use MakinaCorpus\QueryBuilder\Bridge\Doctrine\ErrorConverter\DoctrineErrorConverter;
 use MakinaCorpus\QueryBuilder\Bridge\Doctrine\Escaper\DoctrineEscaper;
 use MakinaCorpus\QueryBuilder\Bridge\Doctrine\Escaper\DoctrineMySQLEscaper;
+use MakinaCorpus\QueryBuilder\Bridge\ErrorConverter;
 use MakinaCorpus\QueryBuilder\Converter\Converter;
 use MakinaCorpus\QueryBuilder\Error\QueryBuilderError;
 use MakinaCorpus\QueryBuilder\Escaper\Escaper;
+use MakinaCorpus\QueryBuilder\Platform;
 use MakinaCorpus\QueryBuilder\Result\IterableResult;
 use MakinaCorpus\QueryBuilder\Result\Result;
 use MakinaCorpus\QueryBuilder\Writer\Writer;
@@ -30,6 +32,14 @@ public function __construct(
         $this->connection = $connection;
     }
 
+    /**
+     * Please override.
+     */
+    protected function createErrorConverter(): ErrorConverter
+    {
+        return new DoctrineErrorConverter();
+    }
+
     /**
      * {@inheritdoc}
      */
diff --git a/src/Bridge/Doctrine/ErrorConverter/DoctrineErrorConverter.php b/src/Bridge/Doctrine/ErrorConverter/DoctrineErrorConverter.php
new file mode 100644
index 0000000..fc5dc03
--- /dev/null
+++ b/src/Bridge/Doctrine/ErrorConverter/DoctrineErrorConverter.php
@@ -0,0 +1,95 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Bridge\Doctrine\ErrorConverter;
+
+use Doctrine\DBAL\ConnectionException;
+use Doctrine\DBAL\Exception\ConnectionLost;
+use Doctrine\DBAL\Exception\ConstraintViolationException;
+use Doctrine\DBAL\Exception\DatabaseDoesNotExist;
+use Doctrine\DBAL\Exception\ForeignKeyConstraintViolationException;
+use Doctrine\DBAL\Exception\InvalidFieldNameException;
+use Doctrine\DBAL\Exception\NonUniqueFieldNameException;
+use Doctrine\DBAL\Exception\NotNullConstraintViolationException;
+use Doctrine\DBAL\Exception\TableNotFoundException;
+use Doctrine\DBAL\Exception\UniqueConstraintViolationException;
+use Doctrine\DBAL\Schema\Exception\ColumnDoesNotExist;
+use Doctrine\DBAL\Schema\Exception\TableDoesNotExist;
+use MakinaCorpus\QueryBuilder\Bridge\ErrorConverter;
+use MakinaCorpus\QueryBuilder\Error\Bridge\AmbiguousIdentifierError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ColumnDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\DatabaseObjectDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ForeignKeyConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\NotNullConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TableDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\UnableToConnectError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\UniqueConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Bridge\Pdo\ErrorConverter\PdoSQLiteErrorConverter;
+
+class DoctrineErrorConverter implements ErrorConverter
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function convertError(\Throwable $error, ?string $sql = null, ?string $message = null): \Throwable
+    {
+        $message ??= $error->getMessage();
+
+        if ($error instanceof InvalidFieldNameException || $error instanceof ColumnDoesNotExist) {
+            return new ColumnDoesNotExistError($message, $error->getCode(), $error);
+        }
+
+        if ($error instanceof DatabaseDoesNotExist) {
+            return new DatabaseObjectDoesNotExistError($message, $error->getCode(), $error);
+        }
+
+        if ($error instanceof ForeignKeyConstraintViolationException) {
+            return new ForeignKeyConstraintViolationError($message, $error->getCode(), $error);
+        }
+
+        if ($error instanceof NotNullConstraintViolationException) {
+            return new NotNullConstraintViolationError($message, $error->getCode(), $error);
+        }
+
+        if ($error instanceof TableDoesNotExist || $error instanceof TableNotFoundException) {
+            return new TableDoesNotExistError($message, $error->getCode(), $error);
+        }
+
+        /* if ($error instanceof Foo) {
+            return new TransactionDeadlockError();
+        } */
+
+        /* if ($error instanceof Foo) {
+            return new TransactionLockWaitTimeoutError();
+        } */
+
+        if ($error instanceof ConnectionException || $error instanceof ConnectionLost) {
+            return new UnableToConnectError($message, $error->getCode(), $error);
+        }
+
+        if ($error instanceof UniqueConstraintViolationException) {
+            return new UniqueConstraintViolationError($message, $error->getCode(), $error);
+        }
+
+        /*
+         * More generic errors after.
+         */
+
+        if ($error instanceof NonUniqueFieldNameException) {
+            return new AmbiguousIdentifierError();
+        }
+
+        /* if ($error instanceof Foo) {
+            return new TransactionFailedError();
+        } */
+
+        if ($error instanceof ConstraintViolationException) {
+            return new ConstraintViolationError($message, $error->getCode(), $error);
+        }
+
+        // Provide fallbacks for SQLite, because DBAL don't catch them all.
+        return PdoSQLiteErrorConverter::createErrorFromMessage($error, $sql, $message);
+    }
+}
diff --git a/src/Bridge/ErrorConverter.php b/src/Bridge/ErrorConverter.php
new file mode 100644
index 0000000..9b45754
--- /dev/null
+++ b/src/Bridge/ErrorConverter.php
@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Bridge;
+
+interface ErrorConverter
+{
+    /**
+     * Convert underlaying connector errors to a common error.
+     *
+     * @param \Throwable $error
+     *   Original error from driver.
+     * @param null|string $sqlQuery
+     *   The raw SQL query that is the subject of this error.
+     * @param null|string $message
+     *   Overriden error message, if any.
+     */
+    public function convertError(\Throwable $error, ?string $sql = null, ?string $message = null): \Throwable;
+}
diff --git a/src/Bridge/PassthroughErrorConverter.php b/src/Bridge/PassthroughErrorConverter.php
new file mode 100644
index 0000000..33343a6
--- /dev/null
+++ b/src/Bridge/PassthroughErrorConverter.php
@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Bridge;
+
+/**
+ * Implementation for when the error handling is disabled.
+ *
+ * Useful when configured over a doctrine/dbal bridge in Symfony context and
+ * you want the Query Builder to be absolutely transparently integrated with
+ * it. It's also true for other bridges contextes.
+ */
+class PassthroughErrorConverter implements ErrorConverter
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function convertError(\Throwable $error, ?string $sql = null, ?string $message = null): \Throwable
+    {
+        return $error;
+    }
+}
diff --git a/src/Bridge/Pdo/ErrorConverter/PdoMySQLErrorConverter.php b/src/Bridge/Pdo/ErrorConverter/PdoMySQLErrorConverter.php
new file mode 100644
index 0000000..04bbb94
--- /dev/null
+++ b/src/Bridge/Pdo/ErrorConverter/PdoMySQLErrorConverter.php
@@ -0,0 +1,129 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Bridge\Pdo\ErrorConverter;
+
+use MakinaCorpus\QueryBuilder\Bridge\ErrorConverter;
+use MakinaCorpus\QueryBuilder\Error\Bridge\AmbiguousIdentifierError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ForeignKeyConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\NotNullConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TableDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TransactionDeadlockError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TransactionLockWaitTimeoutError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\UniqueConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ColumnDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ServerError;
+
+class PdoMySQLErrorConverter implements ErrorConverter
+{
+    /**
+     * {@inheritdoc}
+     *
+     * @link http://dev.mysql.com/doc/refman/5.7/en/error-messages-client.html
+     * @link http://dev.mysql.com/doc/refman/5.7/en/error-messages-server.html
+     *
+     * I have to admit, I was largely inspired by Doctrine DBAL for this one.
+     * All credits to the Doctrine team, developers and contributors. You do
+     * very impressive and qualitative work, I hope you will continue forever.
+     * Many thanks to all contributors. If someday you come to France, give me
+     * a call, an email, anything, and I'll pay you a drink, whoever you are.
+     */
+    public function convertError(\Throwable $error, ?string $sql = null, ?string $message = null): \Throwable
+    {
+        if (!$error instanceof \PDOException) {
+            return $error;
+        }
+
+        $errorCode = $error->errorInfo[1] ?? $error->getCode();
+
+        switch ($errorCode) {
+
+            case '1213':
+                return new TransactionDeadlockError($error->getMessage(), $errorCode, $error);
+
+            case '1205':
+                return new TransactionLockWaitTimeoutError($error->getMessage(), $errorCode, $error);
+
+            /*
+            case '1050':
+                // Table exists.
+             */
+
+            case '1051':
+            case '1146':
+                return new TableDoesNotExistError($error->getMessage(), $errorCode, $error);
+
+            case '1216':
+            case '1217':
+            case '1451':
+            case '1452':
+            case '1701':
+                return new ForeignKeyConstraintViolationError($error->getMessage(), $errorCode, $error);
+
+            case '1062':
+            case '1557':
+            case '1569':
+            case '1586':
+                return new UniqueConstraintViolationError($error->getMessage(), $errorCode, $error);
+
+            case '1054':
+                return new ColumnDoesNotExistError($error->getMessage(), $errorCode, $error);
+
+            /*
+            case '1166':
+            case '1611':
+                // Invalid identifier.
+             */
+
+            case '1052':
+            case '1060':
+            case '1110':
+                return new AmbiguousIdentifierError($error->getMessage(), $errorCode, $error);
+
+            /*
+            case '1064':
+            case '1149':
+            case '1287':
+            case '1341':
+            case '1342':
+            case '1343':
+            case '1344':
+            case '1382':
+            case '1479':
+            case '1541':
+            case '1554':
+            case '1626':
+                // Syntax error.
+             */
+
+            /*
+            case '1044':
+            case '1045':
+            case '1046':
+            case '1049':
+            case '1095':
+            case '1142':
+            case '1143':
+            case '1227':
+            case '1370':
+            case '1429':
+            case '2002':
+            case '2005':
+                // Connection error.
+             */
+
+            case '1048':
+            case '1121':
+            case '1138':
+            case '1171':
+            case '1252':
+            case '1263':
+            case '1364':
+            case '1566':
+                return new NotNullConstraintViolationError($error->getMessage(), $errorCode, $error);
+        }
+
+        return new ServerError($error->getMessage(), $errorCode, $error);
+    }
+}
diff --git a/src/Bridge/Pdo/ErrorConverter/PdoPostgreSQLErrorConverter.php b/src/Bridge/Pdo/ErrorConverter/PdoPostgreSQLErrorConverter.php
new file mode 100644
index 0000000..be2bbfc
--- /dev/null
+++ b/src/Bridge/Pdo/ErrorConverter/PdoPostgreSQLErrorConverter.php
@@ -0,0 +1,109 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Bridge\Pdo\ErrorConverter;
+
+use MakinaCorpus\QueryBuilder\Bridge\ErrorConverter;
+use MakinaCorpus\QueryBuilder\Error\Bridge\AmbiguousIdentifierError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ColumnDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ForeignKeyConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\NotNullConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ServerError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TableDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TransactionDeadlockError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TransactionError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\UniqueConstraintViolationError;
+
+class PdoPostgreSQLErrorConverter implements ErrorConverter
+{
+    /**
+     * {@inheritdoc}
+     *
+     * @link http://www.postgresql.org/docs/9.4/static/errcodes-appendix.html
+     *
+     * I have to admit, I was largely inspired by Doctrine DBAL for this one.
+     * All credits to the Doctrine team, developers and contributors. You do
+     * very impressive and qualitative work, I hope you will continue forever.
+     * Many thanks to all contributors. If someday you come to France, give me
+     * a call, an email, anything, and I'll pay you a drink, whoever you are.
+     */
+    public function convertError(\Throwable $error, ?string $sql = null, ?string $message = null): \Throwable
+    {
+        if (!$error instanceof \PDOException) {
+            return $error;
+        }
+
+        $errorCode = $error->errorInfo[1] ?? $error->getCode();
+
+        switch ($errorCode) {
+
+            case '40001':
+            case '40P01':
+                return new TransactionDeadlockError($error->getMessage(), $errorCode, $error);
+
+            case '0A000':
+                // Foreign key constraint violations during a TRUNCATE operation
+                // are considered "feature not supported" in PostgreSQL.
+                if (\strpos($error->getMessage(), 'truncate') !== false) {
+                    return new ForeignKeyConstraintViolationError($error->getMessage(), $errorCode, $error);
+                }
+
+                break;
+
+            case '23502':
+                return new NotNullConstraintViolationError($error->getMessage(), $errorCode, $error);
+
+            case '23503':
+                return new ForeignKeyConstraintViolationError($error->getMessage(), $errorCode, $error);
+
+            case '23505':
+                return new UniqueConstraintViolationError($error->getMessage(), $errorCode, $error);
+
+            /*
+            case '42601':
+                // Syntax error.
+             */
+
+            case '42702':
+                return new AmbiguousIdentifierError($error->getMessage(), $errorCode, $error);
+
+            case '42703':
+                return new ColumnDoesNotExistError($error->getMessage(), $errorCode, $error);
+
+            /*
+            case '42703':
+                // Invalid identifier.
+             */
+
+            case '42P01':
+                return new TableDoesNotExistError($error->getMessage(), $errorCode, $error);
+
+            /*
+            case '42P07':
+                // Table exists.
+             */
+
+            /*
+            case '7':
+                // In some case (mainly connection errors) the PDO exception does not provide a SQLSTATE via its code.
+                // The exception code is always set to 7 here.
+                // We have to match against the SQLSTATE in the error message in these cases.
+                if (\strpos($error->getMessage(), 'SQLSTATE[08006]') !== false) {
+                    // Connection error.
+                }
+
+                break;
+             */
+        }
+
+        // Attempt with classes if we do not handle the specific SQL STATE code.
+        switch (\substr($sqlState, 2)) {
+
+            case '40':
+                return new TransactionError($error->getMessage(), $errorCode, $error);
+        }
+
+        return new ServerError($error->getMessage(), $errorCode, $error);
+    }
+}
diff --git a/src/Bridge/Pdo/ErrorConverter/PdoSQLServerErrorConverter.php b/src/Bridge/Pdo/ErrorConverter/PdoSQLServerErrorConverter.php
new file mode 100644
index 0000000..ef96faf
--- /dev/null
+++ b/src/Bridge/Pdo/ErrorConverter/PdoSQLServerErrorConverter.php
@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Bridge\Pdo\ErrorConverter;
+
+use MakinaCorpus\QueryBuilder\Bridge\ErrorConverter;
+use MakinaCorpus\QueryBuilder\Error\Bridge\AmbiguousIdentifierError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ColumnDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\DatabaseObjectDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ForeignKeyConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\NotNullConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ServerError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TableDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\UnableToConnectError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\UniqueConstraintViolationError;
+
+class PdoSQLServerErrorConverter implements ErrorConverter
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function convertError(\Throwable $error, ?string $sql = null, ?string $message = null): \Throwable
+    {
+        if (!$error instanceof \PDOException) {
+            return $error;
+        }
+
+        $errorCode = $error->errorInfo[1] ?? $error->getCode();
+
+        switch ($errorCode) {
+            /* case 102:
+                return new SyntaxErrorException($exception, $query); */
+
+            case 207:
+                return new ColumnDoesNotExistError($error->getMessage(), (int) $errorCode, $error);
+
+            case 208:
+                return new TableDoesNotExistError($error->getMessage(), (int) $errorCode, $error);
+
+            case 209:
+                return new AmbiguousIdentifierError($error->getMessage(), (int) $errorCode, $error);
+
+            case 515:
+                return new NotNullConstraintViolationError($error->getMessage(), (int) $errorCode, $error);
+
+            case 547:
+            case 4712:
+                return new ForeignKeyConstraintViolationError($error->getMessage(), (int) $errorCode, $error);
+
+            case 2601:
+            case 2627:
+                return new UniqueConstraintViolationError($error->getMessage(), (int) $errorCode, $error);
+
+            case 2714:
+                return new TableDoesNotExistError($error->getMessage(), (int) $errorCode, $error);
+
+            case 3701:
+            case 15151:
+                return new DatabaseObjectDoesNotExistError($error->getMessage(), (int) $errorCode, $error);
+
+            case 11001:
+            case 18456:
+                return new UnableToConnectError($error->getMessage(), (int) $errorCode, $error);
+        }
+
+        return new ServerError($error->getMessage(), $errorCode, $error);
+    }
+}
diff --git a/src/Bridge/Pdo/ErrorConverter/PdoSQLiteErrorConverter.php b/src/Bridge/Pdo/ErrorConverter/PdoSQLiteErrorConverter.php
new file mode 100644
index 0000000..bc01d11
--- /dev/null
+++ b/src/Bridge/Pdo/ErrorConverter/PdoSQLiteErrorConverter.php
@@ -0,0 +1,114 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Bridge\Pdo\ErrorConverter;
+
+use MakinaCorpus\QueryBuilder\Bridge\ErrorConverter;
+use MakinaCorpus\QueryBuilder\Error\Bridge\AmbiguousIdentifierError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ColumnDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\NotNullConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ServerError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TableDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TransactionDeadlockError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\UniqueConstraintViolationError;
+
+class PdoSQLiteErrorConverter implements ErrorConverter
+{
+    public static function createErrorFromMessage(\Throwable $error, ?string $sql = null, ?string $message = null): \Throwable
+    {
+        $message = $error->getMessage();
+        $errorCode = $error->errorInfo[1] ?? $error->getCode();
+
+        // Missing:
+        //   - Connexion error
+        //   - ForeignKeyConstraintViolationError
+        //   - TransactionError
+        //   - UniqueConstraintViolationError
+        //   - Invalid identifier
+        //   - Syntax error
+        //   - Table exists
+
+        if (\str_contains($message, 'database is locked') !== false) {
+            return new TransactionDeadlockError($message, $errorCode, $error);
+        }
+
+        if (
+            \str_contains($message, 'must be unique') !== false ||
+            \str_contains($message, 'is not unique') !== false ||
+            \str_contains($message, 'are not unique') !== false ||
+            \str_contains($message, 'UNIQUE constraint failed') !== false
+        ) {
+            return new UniqueConstraintViolationError($message, $errorCode, $error);
+        }
+
+        if (
+            \str_contains($message, 'may not be NULL') !== false ||
+            \str_contains($message, 'NOT NULL constraint failed') !== false
+        ) {
+            return new NotNullConstraintViolationError($message, $errorCode, $error);
+        }
+
+        if (\str_contains($message, 'no such table:') !== false) {
+            return new TableDoesNotExistError($message, $errorCode, $error);
+        }
+
+        if (\str_contains($message, 'no such column:') !== false) {
+            return new ColumnDoesNotExistError($message, $errorCode, $error);
+        }
+
+        /*
+        if (\str_contains($message, 'already exists') !== false) {
+            return new TableExistsException($exception, $query);
+        }
+         */
+
+        /*
+        if (\str_contains($message, 'has no column named') !== false) {
+            return new InvalidFieldNameException($exception, $query);
+        }
+         */
+
+        if (\str_contains($message, 'ambiguous column name') !== false) {
+            return new AmbiguousIdentifierError($message, $errorCode, $error);
+        }
+
+        /*
+        if (\str_contains($message, 'syntax error') !== false) {
+            return new SyntaxErrorException($exception, $query);
+        }
+         */
+
+        /*
+        if (\str_contains($message, 'attempt to write a readonly database') !== false) {
+            return new ReadOnlyException($exception, $query);
+        }
+         */
+
+        /*
+        if (\str_contains($message, 'unable to open database file') !== false) {
+            return new ConnectionException($exception, $query);
+        }
+         */
+
+        return new ServerError($error->getMessage(), $error->getCode(), $error);
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * I have to admit, I was largely inspired by Doctrine DBAL for this one.
+     * All credits to the Doctrine team, developers and contributors. You do
+     * very impressive and qualitative work, I hope you will continue forever.
+     * Many thanks to all contributors. If someday you come to France, give me
+     * a call, an email, anything, and I'll pay you a drink, whoever you are.
+     */
+    public function convertError(\Throwable $error, ?string $sql = null, ?string $message = null): \Throwable
+    {
+        if (!$error instanceof \PDOException) {
+            return $error;
+        }
+
+        return self::createErrorFromMessage($error, $sql, $message);
+    }
+}
diff --git a/src/Bridge/Pdo/PdoQueryBuilder.php b/src/Bridge/Pdo/PdoQueryBuilder.php
index 81e25cd..178218c 100644
--- a/src/Bridge/Pdo/PdoQueryBuilder.php
+++ b/src/Bridge/Pdo/PdoQueryBuilder.php
@@ -4,12 +4,18 @@
 
 namespace MakinaCorpus\QueryBuilder\Bridge\Pdo;
 
-use MakinaCorpus\QueryBuilder\Platform;
 use MakinaCorpus\QueryBuilder\Bridge\AbstractBridge;
+use MakinaCorpus\QueryBuilder\Bridge\ErrorConverter;
+use MakinaCorpus\QueryBuilder\Bridge\PassthroughErrorConverter;
+use MakinaCorpus\QueryBuilder\Bridge\Pdo\ErrorConverter\PdoMySQLErrorConverter;
+use MakinaCorpus\QueryBuilder\Bridge\Pdo\ErrorConverter\PdoPostgreSQLErrorConverter;
+use MakinaCorpus\QueryBuilder\Bridge\Pdo\ErrorConverter\PdoSQLiteErrorConverter;
+use MakinaCorpus\QueryBuilder\Bridge\Pdo\ErrorConverter\PdoSQLServerErrorConverter;
 use MakinaCorpus\QueryBuilder\Bridge\Pdo\Escaper\PdoEscaper;
 use MakinaCorpus\QueryBuilder\Bridge\Pdo\Escaper\PdoMySQLEscaper;
 use MakinaCorpus\QueryBuilder\Error\QueryBuilderError;
 use MakinaCorpus\QueryBuilder\Escaper\Escaper;
+use MakinaCorpus\QueryBuilder\Platform;
 use MakinaCorpus\QueryBuilder\Result\IterableResult;
 use MakinaCorpus\QueryBuilder\Result\Result;
 
@@ -25,6 +31,21 @@ public function __construct(
         $this->connection = $connection;
     }
 
+    /**
+     * Please override.
+     */
+    protected function createErrorConverter(): ErrorConverter
+    {
+        return match ($this->getServerFlavor()) {
+            Platform::MARIADB => new PdoMySQLErrorConverter(),
+            Platform::MYSQL => new PdoMySQLErrorConverter(),
+            Platform::POSTGRESQL => new PdoPostgreSQLErrorConverter(),
+            Platform::SQLITE => new PdoSQLiteErrorConverter(),
+            Platform::SQLSERVER => new PdoSQLServerErrorConverter(),
+            default => new PassthroughErrorConverter(),
+        };
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -71,7 +92,7 @@ protected function lookupServerVersion(): ?string
         }
 
         // Last resort version string lookup.
-        if (\preg_match('@(\d+\.\d+(\.\d+))@i', $rawVersion)) {
+        if (\preg_match('@(\d+\.\d+(\.\d+))@i', $rawVersion, $matches)) {
             return $matches[1];
         }
 
diff --git a/src/Error/Bridge/AmbiguousIdentifierError.php b/src/Error/Bridge/AmbiguousIdentifierError.php
new file mode 100644
index 0000000..3d867ea
--- /dev/null
+++ b/src/Error/Bridge/AmbiguousIdentifierError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class AmbiguousIdentifierError extends ServerError
+{
+}
diff --git a/src/Error/Bridge/ColumnDoesNotExistError.php b/src/Error/Bridge/ColumnDoesNotExistError.php
new file mode 100644
index 0000000..956d04a
--- /dev/null
+++ b/src/Error/Bridge/ColumnDoesNotExistError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class ColumnDoesNotExistError extends DatabaseObjectDoesNotExistError
+{
+}
diff --git a/src/Error/Bridge/ConstraintViolationError.php b/src/Error/Bridge/ConstraintViolationError.php
new file mode 100644
index 0000000..23745b8
--- /dev/null
+++ b/src/Error/Bridge/ConstraintViolationError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class ConstraintViolationError extends ServerError
+{
+}
diff --git a/src/Error/Bridge/DatabaseObjectDoesNotExistError.php b/src/Error/Bridge/DatabaseObjectDoesNotExistError.php
new file mode 100644
index 0000000..ca8d684
--- /dev/null
+++ b/src/Error/Bridge/DatabaseObjectDoesNotExistError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class DatabaseObjectDoesNotExistError extends ServerError
+{
+}
diff --git a/src/Error/Bridge/ForeignKeyConstraintViolationError.php b/src/Error/Bridge/ForeignKeyConstraintViolationError.php
new file mode 100644
index 0000000..120f586
--- /dev/null
+++ b/src/Error/Bridge/ForeignKeyConstraintViolationError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class ForeignKeyConstraintViolationError extends ConstraintViolationError
+{
+}
diff --git a/src/Error/Bridge/NotNullConstraintViolationError.php b/src/Error/Bridge/NotNullConstraintViolationError.php
new file mode 100644
index 0000000..37ef404
--- /dev/null
+++ b/src/Error/Bridge/NotNullConstraintViolationError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class NotNullConstraintViolationError extends ConstraintViolationError
+{
+}
diff --git a/src/Error/Bridge/ServerError.php b/src/Error/Bridge/ServerError.php
new file mode 100644
index 0000000..fa1183a
--- /dev/null
+++ b/src/Error/Bridge/ServerError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class ServerError extends \RuntimeException
+{
+}
diff --git a/src/Error/Bridge/TableDoesNotExistError.php b/src/Error/Bridge/TableDoesNotExistError.php
new file mode 100644
index 0000000..369dc15
--- /dev/null
+++ b/src/Error/Bridge/TableDoesNotExistError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class TableDoesNotExistError extends DatabaseObjectDoesNotExistError
+{
+}
diff --git a/src/Error/Bridge/TransactionDeadlockError.php b/src/Error/Bridge/TransactionDeadlockError.php
new file mode 100644
index 0000000..429d555
--- /dev/null
+++ b/src/Error/Bridge/TransactionDeadlockError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class TransactionDeadlockError extends TransactionError
+{
+}
diff --git a/src/Error/Bridge/TransactionError.php b/src/Error/Bridge/TransactionError.php
new file mode 100644
index 0000000..e392384
--- /dev/null
+++ b/src/Error/Bridge/TransactionError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class TransactionError extends ServerError
+{
+}
diff --git a/src/Error/Bridge/TransactionFailedError.php b/src/Error/Bridge/TransactionFailedError.php
new file mode 100644
index 0000000..61c9f4f
--- /dev/null
+++ b/src/Error/Bridge/TransactionFailedError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class TransactionFailedError extends TransactionError
+{
+}
diff --git a/src/Error/Bridge/TransactionLockWaitTimeoutError.php b/src/Error/Bridge/TransactionLockWaitTimeoutError.php
new file mode 100644
index 0000000..0c4f4ff
--- /dev/null
+++ b/src/Error/Bridge/TransactionLockWaitTimeoutError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class TransactionLockWaitTimeoutError extends TransactionError
+{
+}
diff --git a/src/Error/Bridge/UnableToConnectError.php b/src/Error/Bridge/UnableToConnectError.php
new file mode 100644
index 0000000..1b0495d
--- /dev/null
+++ b/src/Error/Bridge/UnableToConnectError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class UnableToConnectError extends ServerError
+{
+}
diff --git a/src/Error/Bridge/UniqueConstraintViolationError.php b/src/Error/Bridge/UniqueConstraintViolationError.php
new file mode 100644
index 0000000..278ae7d
--- /dev/null
+++ b/src/Error/Bridge/UniqueConstraintViolationError.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Error\Bridge;
+
+class UniqueConstraintViolationError extends ConstraintViolationError
+{
+}
diff --git a/src/QueryExecutor.php b/src/QueryExecutor.php
index 61ec27b..4488f70 100644
--- a/src/QueryExecutor.php
+++ b/src/QueryExecutor.php
@@ -4,7 +4,9 @@
 
 namespace MakinaCorpus\QueryBuilder;
 
+use MakinaCorpus\QueryBuilder\Error\Bridge\TransactionError;
 use MakinaCorpus\QueryBuilder\Result\Result;
+use MakinaCorpus\QueryBuilder\Transaction\Transaction;
 
 /**
  * Executes query.
diff --git a/tests/Bridge/AbstractErrorConverterTestCase.php b/tests/Bridge/AbstractErrorConverterTestCase.php
new file mode 100644
index 0000000..5ec9089
--- /dev/null
+++ b/tests/Bridge/AbstractErrorConverterTestCase.php
@@ -0,0 +1,316 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Tests\Bridge;
+
+use MakinaCorpus\QueryBuilder\Platform;
+use MakinaCorpus\QueryBuilder\Error\Bridge\AmbiguousIdentifierError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ColumnDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\ForeignKeyConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TableDoesNotExistError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\UniqueConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Tests\FunctionalTestCase;
+use MakinaCorpus\QueryBuilder\Transaction\Transaction;
+
+abstract class AbstractErrorConverterTestCase extends FunctionalTestCase
+{
+    /** @before */
+    protected function createSchema(): void
+    {
+        try {
+            $this->getBridge()->executeStatement(
+                <<<SQL
+                DROP TABLE foo
+                SQL
+            );
+        } catch (\Throwable) {}
+
+        try {
+            $this->getBridge()->executeStatement(
+                <<<SQL
+                DROP TABLE bar
+                SQL
+            );
+        } catch (\Throwable) {}
+
+        switch ($this->getBridge()->getServerFlavor()) {
+
+            case Platform::MARIADB:
+            case Platform::MYSQL:
+                $this->getBridge()->executeStatement(
+                    <<<SQL
+                    CREATE TABLE foo (
+                        id int UNIQUE NOT NULL,
+                        name varchar(255) UNIQUE NOT NULL,
+                        date datetime DEFAULT now()
+                    )
+                    SQL
+                );
+                $this->getBridge()->executeStatement(
+                    <<<SQL
+                    CREATE TABLE bar (
+                        id int UNIQUE NOT NULL,
+                        foo_id INT DEFAULT NULL,
+                        data text DEFAULT NULL,
+                        CONSTRAINT bar_foo_id_fk FOREIGN KEY (foo_id)
+                            REFERENCES bar (id)
+                            ON DELETE CASCADE
+                    )
+                    SQL
+                );
+                break;
+
+            case Platform::SQLSERVER:
+                $this->getBridge()->executeStatement(
+                    <<<SQL
+                    CREATE TABLE foo (
+                        id int UNIQUE NOT NULL,
+                        name nvarchar(500) UNIQUE NOT NULL,
+                        date datetime2(6) DEFAULT current_timestamp
+                    )
+                    SQL
+                );
+                $this->getBridge()->executeStatement(
+                    <<<SQL
+                    CREATE TABLE bar (
+                        id int UNIQUE NOT NULL,
+                        foo_id INT DEFAULT NULL,
+                        data nvarchar(500) DEFAULT NULL,
+                        CONSTRAINT bar_foo_id_fk FOREIGN KEY (foo_id)
+                            REFERENCES bar (id)
+                            ON DELETE CASCADE
+                    )
+                    SQL
+                );
+                break;
+
+            default:
+                $this->getBridge()->executeStatement(
+                    <<<SQL
+                    CREATE TABLE foo (
+                        id int UNIQUE NOT NULL,
+                        name text UNIQUE NOT NULL,
+                        date timestamp DEFAULT current_timestamp
+                    )
+                    SQL
+                );
+                $this->getBridge()->executeStatement(
+                    <<<SQL
+                    CREATE TABLE bar (
+                        id int UNIQUE NOT NULL,
+                        foo_id INT DEFAULT NULL,
+                        data text DEFAULT NULL,
+                        CONSTRAINT bar_foo_id_fk FOREIGN KEY (foo_id)
+                            REFERENCES bar (id)
+                            ON DELETE CASCADE
+                    )
+                    SQL
+                );
+                break;
+        }
+    }
+
+    public function testAmbiguousIdentifierError(): void
+    {
+        self::expectException(AmbiguousIdentifierError::class);
+
+        $this->getBridge()->executeStatement(
+            <<<SQL
+            SELECT id FROM foo, bar;
+            SQL
+        );
+    }
+
+    public function testConstraintViolationError(): void
+    {
+        self::markTestIncomplete("Not implemented yet.");
+    }
+
+    public function testDatabaseObjectDoesNotExistsError(): void
+    {
+        self::markTestIncomplete("Not implemented yet.");
+    }
+
+    public function testColumnDoesNotExistsError(): void
+    {
+        self::expectException(ColumnDoesNotExistError::class);
+
+        $this->getBridge()->executeStatement(
+            <<<SQL
+            SELECT this_column_does_not_exist FROM foo;
+            SQL
+        );
+    }
+
+    public function testForeignKeyConstraintViolationError(): void
+    {
+        self::expectException(ForeignKeyConstraintViolationError::class);
+
+        $this->getBridge()->executeStatement(
+            <<<SQL
+            INSERT INTO bar (id, foo_id) VALUES (12, 34);
+            SQL
+        );
+    }
+
+    public function testTableDoesNotExistError(): void
+    {
+        self::expectException(TableDoesNotExistError::class);
+
+        $this->getBridge()->executeStatement(
+            <<<SQL
+            SELECT * FROM this_table_does_not_exist;
+            SQL
+        );
+    }
+
+    public function testUniqueConstraintViolationError(): void
+    {
+        $this->getBridge()->executeStatement(
+            <<<SQL
+            INSERT INTO foo (id, name) VALUES (1, 'foo');
+            SQL
+        );
+
+        self::expectException(UniqueConstraintViolationError::class);
+
+        $this->getBridge()->executeStatement(
+            <<<SQL
+            INSERT INTO foo (id, name) VALUES (2, 'foo');
+            SQL
+        );
+    }
+
+    /**
+     * Scenario here comes from official PostgreSQL documentation.
+     *
+     * @link https://www.postgresql.org/docs/10/transaction-iso.html#XACT-SERIALIZABLE
+     */
+    public function testTransactionSerializationError1(): void
+    {
+        self::markTestIncomplete("This test requires two different connections, this is unhanlded yet.");
+
+        $bridge = $this->getBridge();
+
+        if (!$runner1->getPlatform()->supportsSchema()) {
+            self::markTestSkipped("This test requires a schema.");
+        }
+        self::markTestIncomplete("Why does the heck it does not fail?");
+
+        $runner2 = $factory->getRunner();
+
+        $runner1->execute(
+            <<<SQL
+            DROP TABLE IF EXISTS public.test_transaction_1
+            SQL
+        );
+
+        $runner1->execute(
+            <<<SQL
+            CREATE TABLE IF NOT EXISTS public.test_transaction_1 (class int, value int)
+            SQL
+        );
+
+        $runner1->execute(
+            <<<SQL
+            INSERT INTO public.test_transaction_1 (class, value)
+            VALUES (
+                1, 10
+            ), (
+                1, 20
+            ), (
+                2, 100
+            ), (
+                2, 200
+            )
+            SQL
+        );
+
+        // Default level is REPEATABLE READ.
+        $transaction1 = $runner1->beginTransaction(Transaction::SERIALIZABLE);
+        $transaction2 = $runner2->beginTransaction(Transaction::SERIALIZABLE);
+
+        $runner1->execute(
+            <<<SQL
+            SELECT SUM(value) FROM public.test_transaction_1 WHERE class = 1;
+            SQL
+        );
+
+        $runner1->execute(
+            <<<SQL
+            INSERT INTO public.test_transaction_1 (class, value) VALUES (2, 30)
+            SQL
+        );
+
+        $runner2->execute(
+            <<<SQL
+            SELECT SUM(value) FROM public.test_transaction_1 WHERE class = 2;
+            SQL
+        );
+
+        $runner2->execute(
+            <<<SQL
+            INSERT INTO public.test_transaction_1 (class, value) VALUES (1, 300)
+            SQL
+        );
+
+        $transaction1->commit();
+        $transaction2->commit();
+    }
+
+    public function testTransactionSerializationError2(): void
+    {
+        self::markTestIncomplete("This test requires two different connections, this is unhanlded yet.");
+
+        $runner1 = $factory->getRunner();
+
+        if (!$runner1->getPlatform()->supportsSchema()) {
+            self::markTestSkipped("This test requires a schema.");
+        }
+        self::markTestIncomplete("This test requires that we send a query batch asynchronously in the second transaction.");
+
+        $runner2 = $factory->getRunner();
+
+        $runner1->execute(
+            <<<SQL
+            DROP TABLE IF EXISTS public.test_transaction_2
+            SQL
+        );
+
+        $runner1->execute(
+            <<<SQL
+            CREATE TABLE IF NOT EXISTS public.test_transaction_2 (id int PRIMARY KEY)
+            SQL
+        );
+
+        // Default level is REPEATABLE READ.
+        $transaction1 = $runner1->beginTransaction(Transaction::SERIALIZABLE);
+        $transaction2 = $runner2->beginTransaction(Transaction::SERIALIZABLE);
+
+        $runner1->execute(
+            <<<SQL
+            INSERT INTO public.test_transaction_2 (id) VALUES (1)
+            SQL
+        );
+
+        $runner2->execute(
+            <<<SQL
+            INSERT INTO public.test_transaction_2 (id) VALUES (1)
+            SQL
+        );
+
+        $transaction1->commit();
+        $transaction2->commit();
+    }
+
+    public function testTransactionDeadlockError(): void
+    {
+        self::markTestIncomplete("Not implemented yet.");
+    }
+
+    public function testTransactionWaitTimeoutError(): void
+    {
+        self::markTestIncomplete("Not implemented yet.");
+    }
+}
diff --git a/tests/Bridge/Doctrine/DoctrineErrorConverterTest.php b/tests/Bridge/Doctrine/DoctrineErrorConverterTest.php
new file mode 100644
index 0000000..cfd1c9c
--- /dev/null
+++ b/tests/Bridge/Doctrine/DoctrineErrorConverterTest.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Tests\Bridge\Doctrine;
+
+use MakinaCorpus\QueryBuilder\Testing\FunctionalDoctrineTestCaseTrait;
+use MakinaCorpus\QueryBuilder\Tests\Bridge\AbstractErrorConverterTestCase;
+
+class DoctrineErrorConverterTest extends AbstractErrorConverterTestCase
+{
+    use FunctionalDoctrineTestCaseTrait;
+}
diff --git a/tests/Bridge/Pdo/PdoErrorConverterTest.php b/tests/Bridge/Pdo/PdoErrorConverterTest.php
new file mode 100644
index 0000000..6f3588f
--- /dev/null
+++ b/tests/Bridge/Pdo/PdoErrorConverterTest.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Tests\Bridge\Doctrine;
+
+use MakinaCorpus\QueryBuilder\Testing\FunctionalPdoTestCaseTrait;
+use MakinaCorpus\QueryBuilder\Tests\Bridge\AbstractErrorConverterTestCase;
+
+class PdoErrorConverterTest extends AbstractErrorConverterTestCase
+{
+    use FunctionalPdoTestCaseTrait;
+}
diff --git a/tests/Functional/TransactionFunctionalTest.php b/tests/Functional/TransactionFunctionalTest.php
new file mode 100644
index 0000000..90b13e4
--- /dev/null
+++ b/tests/Functional/TransactionFunctionalTest.php
@@ -0,0 +1,491 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MakinaCorpus\QueryBuilder\Tests\Functional;
+
+use MakinaCorpus\QueryBuilder\Platform;
+use MakinaCorpus\QueryBuilder\Error\Bridge\TransactionError;
+use MakinaCorpus\QueryBuilder\Error\Bridge\UniqueConstraintViolationError;
+use MakinaCorpus\QueryBuilder\Tests\Bridge\Doctrine\DoctrineTestCase;
+use MakinaCorpus\QueryBuilder\Transaction\Transaction;
+use MakinaCorpus\QueryBuilder\Transaction\TransactionSavepoint;
+
+final class TransactionFunctionalTest extends DoctrineTestCase
+{
+    /** @before */
+    protected function createSchema(): void
+    {
+        $bridge = $this->getBridge();
+
+        try {
+            $bridge->executeStatement(
+                <<<SQL
+                DROP TABLE transaction_test
+                SQL
+            );
+        } catch (\Throwable) {}
+
+        switch ($bridge->getServerFlavor()) {
+
+            case Platform::MARIADB:
+            case Platform::MYSQL:
+                $bridge->executeStatement(
+                    <<<SQL
+                    CREATE TABLE transaction_test (
+                        id serial PRIMARY KEY,
+                        foo integer NOT NULL,
+                        bar varchar(255) DEFAULT NULL
+                    )
+                    SQL
+                );
+                $bridge->executeStatement(
+                    <<<SQL
+                    alter table transaction_test
+                        add constraint transaction_test_foo
+                        unique (foo)
+                    SQL
+                );
+                $bridge->executeStatement(
+                    <<<SQL
+                    alter table transaction_test
+                        add constraint transaction_test_bar
+                        unique (bar)
+                    SQL
+                );
+                break;
+
+            case Platform::SQLSERVER:
+                $bridge->executeStatement(
+                    <<<SQL
+                    CREATE TABLE transaction_test (
+                        id serial PRIMARY KEY,
+                        foo integer NOT NULL,
+                        bar nvarchar(255) DEFAULT NULL
+                    )
+                    SQL
+                );
+                $bridge->executeStatement(
+                    <<<SQL
+                    alter table transaction_test
+                        add constraint transaction_test_foo
+                        unique (foo)
+                        deferrable
+                    SQL
+                );
+                $bridge->executeStatement(
+                    <<<SQL
+                    alter table transaction_test
+                        add constraint transaction_test_bar
+                        unique (bar)
+                        deferrable
+                    SQL
+                );
+                break;
+
+            default:
+                $bridge->executeStatement(
+                    <<<SQL
+                    CREATE TABLE transaction_test (
+                        id serial PRIMARY KEY,
+                        foo integer NOT NULL,
+                        bar varchar(255) DEFAULT NULL
+                    )
+                    SQL
+                );
+                $bridge->executeStatement(
+                    <<<SQL
+                    alter table transaction_test
+                        add constraint transaction_test_foo
+                        unique (foo)
+                        deferrable
+                    SQL
+                );
+                $bridge->executeStatement(
+                    <<<SQL
+                    alter table transaction_test
+                        add constraint transaction_test_bar
+                        unique (bar)
+                        deferrable
+                    SQL
+                );
+                break;
+        }
+
+        $bridge
+            ->insert('transaction_test')
+            ->columns(['foo', 'bar'])
+            ->values([1, 'a'])
+            ->values([2, 'b'])
+            ->values([3, 'c'])
+            ->executeStatement()
+        ;
+    }
+
+    /**
+     * Normal working transaction.
+     */
+    public function testTransaction()
+    {
+        $bridge = $this->getBridge();
+        $transaction = $bridge->beginTransaction();
+
+        $bridge
+            ->insert('transaction_test')
+            ->columns(['foo', 'bar'])
+            ->values([4, 'd'])
+            ->executeStatement()
+        ;
+
+        $transaction->commit();
+
+        $result = $bridge
+            ->select('transaction_test')
+            ->orderBy('foo')
+            ->executeQuery()
+        ;
+
+        self::assertSame(4, $result->rowCount());
+        self::assertSame('a', $result->fetchRow()->get('bar'));
+        self::assertSame('b', $result->fetchRow()->get('bar'));
+        self::assertSame('c', $result->fetchRow()->get('bar'));
+        self::assertSame('d', $result->fetchRow()->get('bar'));
+    }
+
+    public function testNestedTransactionCreatesSavepoint()
+    {
+        $bridge = $this->getBridge();
+
+        /* if (!$bridge->getPlatform()->supportsTransactionSavepoints()) {
+            self::markTestSkipped(\sprintf("Driver '%s' does not supports savepoints", $bridge->getDriverName()));
+        } */
+
+        $bridge->delete('transaction_test')->executeStatement();
+
+        $transaction = $bridge->beginTransaction();
+
+        $bridge
+            ->insert('transaction_test')
+            ->columns(['foo', 'bar'])
+            ->values([789, 'f'])
+            ->executeStatement()
+        ;
+
+        $savepoint = $bridge->beginTransaction();
+
+        self::assertInstanceOf(TransactionSavepoint::class, $savepoint);
+        self::assertTrue($savepoint->isNested());
+        self::assertNotNull($savepoint->getSavepointName());
+
+        $bridge
+            ->insert('transaction_test')
+            ->columns(['foo', 'bar'])
+            ->values([456, 'g'])
+            ->executeStatement()
+        ;
+
+        $transaction->commit();
+
+        $result = $bridge
+            ->select('transaction_test')
+            ->orderBy('foo')
+            ->executeQuery()
+        ;
+
+        self::assertSame(2, $result->rowCount());
+        self::assertSame('g', $result->fetchRow()->get('bar'));
+        self::assertSame('f', $result->fetchRow()->get('bar'));
+    }
+
+    public function testNestedTransactionRollbackToSavepointTransparently()
+    {
+        $bridge = $this->getBridge();
+
+        /* if (!$bridge->getPlatform()->supportsTransactionSavepoints()) {
+            self::markTestSkipped(\sprintf("Driver '%s' does not supports savepoints", $bridge->getDriverName()));
+        } */
+
+        $bridge->delete('transaction_test')->executeStatement();
+
+        $transaction = $bridge->beginTransaction();
+
+        $bridge
+            ->insert('transaction_test')
+            ->columns(['foo', 'bar'])
+            ->values([789, 'f'])
+            ->executeStatement()
+        ;
+
+        $savepoint = $bridge->beginTransaction();
+
+        self::assertInstanceOf(TransactionSavepoint::class, $savepoint);
+        self::assertTrue($savepoint->isNested());
+        self::assertNotNull($savepoint->getSavepointName());
+
+        $bridge
+            ->insert('transaction_test')
+            ->columns(['foo', 'bar'])
+            ->values([456, 'g'])
+            ->executeStatement()
+        ;
+
+        $savepoint->rollback();
+        $transaction->commit();
+
+        $result = $bridge
+            ->select('transaction_test')
+            ->orderBy('foo')
+            ->executeQuery()
+        ;
+
+        self::assertSame(1, $result->rowCount());
+        self::assertSame('f', $result->fetchRow()->get('bar'));
+    }
+
+    /**
+     * Fail with immediate constraints (not deferred).
+     */
+    public function testImmediateTransactionFail()
+    {
+        $bridge = $this->getBridge();
+
+        $transaction = $bridge
+            ->beginTransaction()
+            ->deferred() // Defer all
+            ->immediate('transaction_test_bar')
+        ;
+
+        try {
+            // This should pass, foo constraint it deferred;
+            // if backend does not support defering, this will
+            // fail anyway, but the rest of the test is still
+            // valid
+            $bridge
+                ->insert('transaction_test')
+                ->columns(['foo', 'bar'])
+                ->values([2, 'd'])
+                ->executeStatement()
+            ;
+
+            // This should fail, bar constraint it immediate
+            $bridge
+                ->insert('transaction_test')
+                ->columns(['foo', 'bar'])
+                ->values([5, 'b'])
+                ->executeStatement()
+            ;
+
+            self::fail();
+
+        } catch (TransactionError $e) {
+            self::assertInstanceOf(UniqueConstraintViolationError::class, $e->getPrevious());
+        } finally {
+            if ($transaction->isStarted()) {
+                $transaction->rollback();
+            }
+        }
+    }
+
+    /**
+     * Fail with deferred constraints.
+     */
+    public function testDeferredTransactionFail()
+    {
+        $bridge = $this->getBridge();
+
+        /* if (!$bridge->getPlatform()->supportsDeferingConstraints()) {
+            self::markTestSkipped("driver does not support defering constraints");
+        } */
+
+        $transaction = $bridge
+            ->beginTransaction()
+            ->immediate() // Immediate all
+            ->deferred('transaction_test_foo')
+        ;
+
+        try {
+
+            // This should pass, foo constraint it deferred
+            $bridge
+                ->insert('transaction_test')
+                ->columns(['foo', 'bar'])
+                ->values([2, 'd'])
+                ->executeStatement()
+            ;
+
+            // This should fail, bar constraint it immediate
+            $bridge
+                ->insert('transaction_test')
+                ->columns(['foo', 'bar'])
+                ->values([5, 'b'])
+                ->executeStatement()
+            ;
+
+            self::fail();
+
+        } catch (TransactionError $e) {
+            self::assertInstanceOf(UniqueConstraintViolationError::class, $e->getPrevious());
+        } finally {
+            if ($transaction->isStarted()) {
+                $transaction->rollback();
+            }
+        }
+
+        self::assertTrue(true);
+    }
+
+    /**
+     * Fail with ALL constraints deferred.
+     */
+    public function testDeferredAllTransactionFail()
+    {
+        $bridge = $this->getBridge();
+
+        /* if (!$bridge->getPlatform()->supportsDeferingConstraints()) {
+            self::markTestSkipped("driver does not support defering constraints");
+        } */
+
+        $transaction = $bridge
+            ->beginTransaction()
+            ->deferred()
+        ;
+
+        try {
+
+            // This should pass, all are deferred
+            $bridge
+                ->insert('transaction_test')
+                ->columns(['foo', 'bar'])
+                ->values([2, 'd'])
+                ->executeStatement()
+            ;
+
+            // This should pass, all are deferred
+            $bridge
+                ->insert('transaction_test')
+                ->columns(['foo', 'bar'])
+                ->values([5, 'b'])
+                ->executeStatement()
+            ;
+
+            $transaction->commit();
+
+        } catch (TransactionError $e) {
+            self::assertInstanceOf(UniqueConstraintViolationError::class, $e->getPrevious());
+        } finally {
+            if ($transaction->isStarted()) {
+                $transaction->rollback();
+            }
+        }
+
+        self::assertTrue(true);
+    }
+
+    /**
+     * Tests that rollback works.
+     */
+    public function testTransactionRollback()
+    {
+        $bridge = $this->getBridge();
+
+        $transaction = $bridge->beginTransaction();
+
+        $bridge
+            ->insert('transaction_test')
+            ->columns(['foo', 'bar'])
+            ->values([4, 'd'])
+            ->executeStatement()
+        ;
+
+        $transaction->rollback();
+
+        $result = $bridge
+            ->select('transaction_test')
+            ->executeQuery()
+        ;
+
+        self::assertSame(3, $result->rowCount());
+    }
+
+    /**
+     * Test that fetching a pending transaction is disallowed.
+     */
+    public function testPendingAllowed()
+    {
+        $bridge = $this->getBridge();
+
+        $transaction = $bridge->beginTransaction();
+
+        // Fetch another transaction, it should fail
+        try {
+            $bridge->beginTransaction(Transaction::REPEATABLE_READ, false);
+            self::fail();
+        } catch (TransactionError $e) {
+        }
+
+        // Fetch another transaction, it should NOT fail
+        $t3 = $bridge->beginTransaction(Transaction::REPEATABLE_READ, true);
+        // @todo temporary deactivating this test since that the profiling
+        //   transaction makes it harder
+        //self::assertSame($t3, $transaction);
+        self::assertTrue($t3->isStarted());
+
+        // Force rollback of the second, ensure previous is stopped too
+        $t3->rollback();
+        self::assertFalse($t3->isStarted());
+        // Still true, because we acquired a savepoint
+        self::assertTrue($transaction->isStarted());
+
+        $transaction->rollback();
+        self::assertFalse($transaction->isStarted());
+    }
+
+    /**
+     * Test the savepoint feature.
+     */
+    public function testTransactionSavepoint()
+    {
+        $bridge = $this->getBridge();
+
+        $transaction = $bridge->beginTransaction();
+
+        $bridge
+            ->update('transaction_test')
+            ->set('bar', 'z')
+            ->where('foo', 1)
+            ->executeStatement()
+        ;
+
+        $transaction->savepoint('bouyaya');
+
+        $bridge
+            ->update('transaction_test')
+            ->set('bar', 'y')
+            ->where('foo', 2)
+            ->executeStatement()
+        ;
+
+        $transaction->rollbackToSavepoint('bouyaya');
+        $transaction->commit();
+
+        $oneBar = $bridge
+            ->select('transaction_test')
+            ->column('bar')
+            ->where('foo', 1)
+            ->executeQuery()
+            ->fetchOne()
+        ;
+        // This should have pass since it's before the savepoint
+        self::assertSame('z', $oneBar);
+
+        $twoBar = $bridge
+            ->select('transaction_test')
+            ->column('bar')
+            ->where('foo', 2)
+            ->executeQuery()
+            ->fetchOne()
+        ;
+        // This should not have pass thanks to savepoint
+        self::assertSame('b', $twoBar);
+    }
+}