feat: add constraint violation database exceptions

system/Database/BaseConnection.php

@@ -15,7 +15,11 @@
 
 use BackedEnum;
 use Closure;
+use CodeIgniter\Database\Exceptions\CheckConstraintViolationException;
+use CodeIgniter\Database\Exceptions\ConstraintViolationException;
 use CodeIgniter\Database\Exceptions\DatabaseException;
+use CodeIgniter\Database\Exceptions\ForeignKeyConstraintViolationException;
+use CodeIgniter\Database\Exceptions\NotNullConstraintViolationException;
 use CodeIgniter\Database\Exceptions\RetryableTransactionException;
 use CodeIgniter\Database\Exceptions\UniqueConstraintViolationException;
 use CodeIgniter\Events\Events;
@@ -2231,6 +2235,38 @@ protected function isUniqueConstraintViolation(int|string $code, string $message
         return false;
     }
 
+    /**
+     * Checks whether the native database error represents a foreign key constraint violation.
+     */
+    protected function isForeignKeyConstraintViolation(int|string $code, string $message): bool
+    {
+        return false;
+    }
+
+    /**
+     * Checks whether the native database error represents a NOT NULL constraint violation.
+     */
+    protected function isNotNullConstraintViolation(int|string $code, string $message): bool
+    {
+        return false;
+    }
+
+    /**
+     * Checks whether the native database error represents a CHECK constraint violation.
+     */
+    protected function isCheckConstraintViolation(int|string $code, string $message): bool
+    {
+        return false;
+    }
+
+    /**
+     * Checks whether the native database error represents a constraint violation.
+     */
+    protected function isConstraintViolation(int|string $code, string $message): bool
+    {
+        return false;
+    }
+
     /**
      * Checks whether the native database code represents a retryable transaction failure.
      */
@@ -2253,6 +2289,22 @@ public function createDatabaseException(
             return new UniqueConstraintViolationException($message, $code, $previous);
         }
 
+        if ($this->isForeignKeyConstraintViolation($code, $message)) {
+            return new ForeignKeyConstraintViolationException($message, $code, $previous);
+        }
+
+        if ($this->isNotNullConstraintViolation($code, $message)) {
+            return new NotNullConstraintViolationException($message, $code, $previous);
+        }
+
+        if ($this->isCheckConstraintViolation($code, $message)) {
+            return new CheckConstraintViolationException($message, $code, $previous);
+        }
+
+        if ($this->isConstraintViolation($code, $message)) {
+            return new ConstraintViolationException($message, $code, $previous);
+        }
+
         if ($this->isRetryableTransactionErrorCode($code)) {
             return new RetryableTransactionException($message, $code, $previous);
         }

system/Database/Exceptions/CheckConstraintViolationException.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Database\Exceptions;
+
+/**
+ * Thrown when a CHECK constraint is violated.
+ */
+class CheckConstraintViolationException extends ConstraintViolationException
+{
+}

system/Database/Exceptions/ConstraintViolationException.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Database\Exceptions;
+
+/**
+ * Thrown when a database integrity constraint is violated.
+ */
+class ConstraintViolationException extends DatabaseException
+{
+}

system/Database/Exceptions/ForeignKeyConstraintViolationException.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Database\Exceptions;
+
+/**
+ * Thrown when a foreign key constraint is violated.
+ */
+class ForeignKeyConstraintViolationException extends ConstraintViolationException
+{
+}

system/Database/Exceptions/NotNullConstraintViolationException.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Database\Exceptions;
+
+/**
+ * Thrown when a NOT NULL constraint is violated.
+ */
+class NotNullConstraintViolationException extends ConstraintViolationException
+{
+}

system/Database/Exceptions/UniqueConstraintViolationException.php

@@ -13,6 +13,9 @@
 
 namespace CodeIgniter\Database\Exceptions;
 
-class UniqueConstraintViolationException extends DatabaseException
+/**
+ * Thrown when a unique constraint is violated.
+ */
+class UniqueConstraintViolationException extends ConstraintViolationException
 {
 }

system/Database/MySQLi/Connection.php

@@ -106,6 +106,37 @@ protected function isUniqueConstraintViolation(int|string $code, string $message
         return $code === 1062;
     }
 
+    /**
+     * Checks whether the native database error represents a foreign key constraint violation.
+     */
+    protected function isForeignKeyConstraintViolation(int|string $code, string $message): bool
+    {
+        // ER_NO_REFERENCED_ROW, ER_ROW_IS_REFERENCED, ER_ROW_IS_REFERENCED_2, ER_NO_REFERENCED_ROW_2.
+        return in_array($code, [1216, 1217, 1451, 1452], true);
+    }
+
+    /**
+     * Checks whether the native database error represents a NOT NULL constraint violation.
+     */
+    protected function isNotNullConstraintViolation(int|string $code, string $message): bool
+    {
+        // ER_BAD_NULL_ERROR, ER_BAD_NULL_ERROR_NOT_IGNORED: column cannot be null.
+        return in_array($code, [1048, 3673], true);
+    }
+
+    /**
+     * Checks whether the native database error represents a CHECK constraint violation.
+     */
+    protected function isCheckConstraintViolation(int|string $code, string $message): bool
+    {
+        if ($code === 3819) {
+            return true;
+        }
+
+        // MariaDB reports CHECK failures as ER_CONSTRAINT_FAILED, while MySQL uses 4025 for other errors.
+        return $code === 4025 && str_contains(strtolower($this->getVersion()), 'mariadb');
+    }
+
     /**
      * Checks whether the native database code represents a retryable transaction failure.
      */

system/Database/OCI8/Connection.php

@@ -123,6 +123,33 @@ protected function isUniqueConstraintViolation(int|string $code, string $message
         return (int) $code === 1;
     }
 
+    /**
+     * Checks whether the native database error represents a foreign key constraint violation.
+     */
+    protected function isForeignKeyConstraintViolation(int|string $code, string $message): bool
+    {
+        // ORA-02291: parent key not found; ORA-02292: child record found.
+        return in_array((int) $code, [2291, 2292], true);
+    }
+
+    /**
+     * Checks whether the native database error represents a NOT NULL constraint violation.
+     */
+    protected function isNotNullConstraintViolation(int|string $code, string $message): bool
+    {
+        // ORA-01400: cannot insert NULL; ORA-01407: cannot update to NULL.
+        return in_array((int) $code, [1400, 1407], true);
+    }
+
+    /**
+     * Checks whether the native database error represents a CHECK constraint violation.
+     */
+    protected function isCheckConstraintViolation(int|string $code, string $message): bool
+    {
+        // ORA-02290: check constraint violated.
+        return (int) $code === 2290;
+    }
+
     /**
      * Checks whether the native database code represents a retryable transaction failure.
      */

system/Database/Postgre/Connection.php

@@ -71,6 +71,38 @@ protected function isUniqueConstraintViolation(int|string $code, string $message
         return $code === '23505';
     }
 
+    /**
+     * Checks whether the native database error represents a foreign key constraint violation.
+     */
+    protected function isForeignKeyConstraintViolation(int|string $code, string $message): bool
+    {
+        return $code === '23503';
+    }
+
+    /**
+     * Checks whether the native database error represents a NOT NULL constraint violation.
+     */
+    protected function isNotNullConstraintViolation(int|string $code, string $message): bool
+    {
+        return $code === '23502';
+    }
+
+    /**
+     * Checks whether the native database error represents a CHECK constraint violation.
+     */
+    protected function isCheckConstraintViolation(int|string $code, string $message): bool
+    {
+        return $code === '23514';
+    }
+
+    /**
+     * Checks whether the native database error represents a constraint violation.
+     */
+    protected function isConstraintViolation(int|string $code, string $message): bool
+    {
+        return is_string($code) && str_starts_with($code, '23');
+    }
+
     /**
      * Checks whether the native database code represents a retryable transaction failure.
      */

system/Database/SQLSRV/Connection.php

@@ -94,14 +94,10 @@ class Connection extends BaseConnection
      */
     protected function isUniqueConstraintViolation(int|string $code, string $message): bool
     {
-        $code = (string) $code;
+        $vendorCode = $this->getVendorErrorCode($code);
 
-        if (str_contains($code, '/')) {
-            [$sqlstate, $vendorCode] = explode('/', $code, 2);
-
-            if ($sqlstate === '23000' && in_array((int) $vendorCode, [2627, 2601], true)) {
-                return true;
-            }
+        if ($vendorCode !== null && in_array($vendorCode, [2627, 2601], true)) {
+            return $this->hasSQLState($code, '23000');
         }
 
         $errors = sqlsrv_errors(SQLSRV_ERR_ERRORS);
@@ -121,20 +117,55 @@ protected function isUniqueConstraintViolation(int|string $code, string $message
         return false;
     }
 
+    /**
+     * Checks whether the native database error represents a NOT NULL constraint violation.
+     */
+    protected function isNotNullConstraintViolation(int|string $code, string $message): bool
+    {
+        return $this->getVendorErrorCode($code) === 515
+            && $this->hasSQLState($code, '23000');
+    }
+
+    /**
+     * Checks whether the native database error represents a constraint violation.
+     */
+    protected function isConstraintViolation(int|string $code, string $message): bool
+    {
+        return $this->getSQLState($code) === '23000'
+            || ($this->getVendorErrorCode($code) === 547 && $this->hasSQLState($code, '23000'));
+    }
+
     /**
      * Checks whether the native database code represents a retryable transaction failure.
      */
     protected function isRetryableTransactionErrorCode(int|string $code): bool
+    {
+        $vendorCode = $this->getVendorErrorCode($code);
+
+        return $vendorCode !== null && in_array($vendorCode, [1205, 3960], true);
+    }
+
+    private function getVendorErrorCode(int|string $code): ?int
     {
         $vendorCode = (string) (is_string($code) && str_contains($code, '/')
             ? substr($code, strrpos($code, '/') + 1)
             : $code);
 
-        if (preg_match('/^\d+$/', $vendorCode) !== 1) {
-            return false;
-        }
+        return preg_match('/^\d+$/', $vendorCode) === 1 ? (int) $vendorCode : null;
+    }
+
+    private function getSQLState(int|string $code): string
+    {
+        return is_string($code) && str_contains($code, '/')
+            ? substr($code, 0, strpos($code, '/'))
+            : (string) $code;
+    }
 
-        return in_array((int) $vendorCode, [1205, 3960], true);
+    private function hasSQLState(int|string $code, string $sqlstate): bool
+    {
+        return ! is_string($code)
+            || ! str_contains($code, '/')
+            || $this->getSQLState($code) === $sqlstate;
     }
 
     /**