implemented DriverException descendants:

- ConstraintViolationException
- ForeignKeyConstraintViolationException
- NotNullConstraintViolationException
- UniqueConstraintViolationException

tests/dibi/exceptions.mysql.phpt

@@ -0,0 +1,41 @@
+<?php
+
+/**
+ * Test: query exceptions.
+ * @dataProvider ../databases.ini mysql
+ */
+
+use Tester\Assert;
+
+require __DIR__ . '/bootstrap.php';
+
+$conn = new Dibi\Connection($config);
+$conn->loadFile(__DIR__ . "/data/$config[system].sql");
+
+
+$e = Assert::exception(function () use ($conn) {
+	$conn->query('SELECT');
+}, 'Dibi\DriverException', "%a% error in your SQL syntax;%a%", 1064);
+
+Assert::same('SELECT', $e->getSql());
+
+
+$e = Assert::exception(function () use ($conn) {
+	$conn->query('INSERT INTO products (product_id, title) VALUES (1, "New")');
+}, 'Dibi\UniqueConstraintViolationException', "Duplicate entry '1' for key 'PRIMARY'", 1062);
+
+Assert::same("INSERT INTO products (product_id, title) VALUES (1, 'New')", $e->getSql());
+
+
+$e = Assert::exception(function () use ($conn) {
+	$conn->query('INSERT INTO products (title) VALUES (NULL)');
+}, 'Dibi\NotNullConstraintViolationException', "Column 'title' cannot be null", 1048);
+
+Assert::same('INSERT INTO products (title) VALUES (NULL)', $e->getSql());
+
+
+$e = Assert::exception(function () use ($conn) {
+	$conn->query('INSERT INTO orders (customer_id, product_id, amount) VALUES (100, 1, 1)');
+}, 'Dibi\ForeignKeyConstraintViolationException', '%a% a foreign key constraint fails %a%', 1452);
+
+Assert::same('INSERT INTO orders (customer_id, product_id, amount) VALUES (100, 1, 1)', $e->getSql());