add readme

Author: JanTvrdik

README.md

@@ -1 +1,52 @@
 # Doctrine Query Checker
+
+Doctrine Query Tree Walker that perform additional checks on the query AST in addition to the default checks performed by Doctrine.
+
+Currently it checks that the types of the parameters passed to the query are correct. For example the following will result in exception:
+
+```php
+// throws 'Parameter "created_at" is of type "string", but expected "datetime" (because it\'s used in expression with u.createdAt)'
+$this->entityManager->createQueryBuilder()
+    ->select('u')
+    ->from(User::class, 'u')
+    ->where('u.createdAt < :created_at')
+    ->setParameter('created_at', 'not a date')
+    ->getQuery()
+    ->setHint(Query::HINT_CUSTOM_TREE_WALKERS, [QueryCheckerTreeWalker::class]);
+    ->getResult();
+```
+
+If you want to log the exceptions instead of throwing them, you can pass a logger to the QueryCheckerTreeWalker:
+
+```php
+QueryCheckerTreeWalker::setLogger($logger);
+```
+
+## Installation
+
+```bash
+composer require shipmonk/doctrine-query-checker
+```
+
+## Enabling for a specific query
+
+```php
+use Doctrine\ORM\Query;
+use ShipMonk\DoctrineQueryChecker\QueryCheckerTreeWalker;
+
+$query = $this->entityManager->createQueryBuilder()
+    ->select('u')
+    ->from(User::class, 'u')
+    ->getQuery()
+    ->setHint(Query::HINT_CUSTOM_TREE_WALKERS, [QueryCheckerTreeWalker::class]);
+```
+
+## Enabling for all queries
+
+```php
+use Doctrine\ORM\Query;
+use ShipMonk\DoctrineQueryChecker\QueryCheckerTreeWalker;
+
+$this->entityManager->getConfiguration()
+    ->setDefaultQueryHint(Query::HINT_CUSTOM_TREE_WALKERS, [QueryCheckerTreeWalker::class]);
+```