Doctrine2,ManyToMany relation=>SQLSTATE[42000]:语法错误或访问冲突

我在项目中使用Doctrine2,我定义了以下实体:

namespace Model;

/**
 * @Entity()
 * @Table(name="author")
 **/
class Author {

    /**
     * @Id
     * @GeneratedValue
     * @Column(type="integer")
     **/
    private $id;

    /** @Column(type="string") **/
    private $firstName;

    /** @Column(type="string") **/
    private $lastName;

    /** @Column(type="string", nullable=true) **/
    private $titleBefore;

    /** @Column(type="string", nullable=true) **/
    private $titleAfter;

    /** @ManyToMany(targetEntity="Article", mappedBy="authors") **/
    private $articles;

    public function __construct() {
        $this->articles = new \Doctrine\Common\Collections\ArrayCollection();
    }

    public function getId() {
        return $this->id;
    }

    public function getTitleBefore() {
        return $this->titleBefore;
    }

    public function setTitleBefore($titleBefore) {
        $this->titleBefore = $titleBefore;
    }

    public function getTitleAfter() {
        return $this->titleAfter;
    }

    public function setTitleAfter($titleAfter) {
        $this->titleAfter = $titleAfter;
    }

    public function getLastName() {
        return $this->lastName;
    }

    public function setLastName($lastName) {
        $this->lastName = $lastName;
    }

    public function getFirstName() {
        return $this->firstName;
    }

    public function setFirstName($firstName) {
        $this->firstName = $firstName;
    }

    public function getArticles() {
        return $this->articles;
    }

    public function addArticle($article) {
        $this->articles->add($article);
    }
}

和

namespace Model;

/**
 * @Entity()
 * @Table(name="article")
 **/
class Article {

    /**
     * @Id
     * @GeneratedValue
     * @Column(type="integer")
     **/
    private $id;

    /** @Column(type="string") **/
    private $name;

    /** @OneToOne(targetEntity="Publication") **/
    private $publication;

    /**
     * @ManyToMany(targetEntity="Author", mappedBy="articles")
     */
    private $authors;

    public function __construct() {
        $this->authors = new \Doctrine\Common\Collections\ArrayCollection();
    }

    public function getId() {
        return $this->id;
    }

    public function getName() {
        return $this->name;
    }

    public function setName($name) {
        $this->name = $name;
    }

    public function getPublication() {
        return $this->publication;
    }

    public function setPublication($publication) {
        $this->publication = $publication;
    }

    public function getAuthors() {
        return $this->authors;
    }

    public function addAuthor($author) {
        $this->authors->add($author);
        $author->addArticle($this);
    }

    public function setAuthors($authors) {
        $this->authors = $authors;
    }
}

看起来,那个关系作者<-&燃气轮机;这篇文章写得很好。虽然我遇到了一个问题。当我尝试像这样访问Smarty模板中的作者时: {foreach from=$article->getAuthors() item=author} ,将引发以下异常:

Fatal error: Uncaught PDOException: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ON' at line 1 in /code/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php:104 Stack trace:
#0 /code/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php(104): PDO->query('SELECT t0.id AS...')
#1 /code/vendor/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(852): Doctrine\DBAL\Driver\PDOConnection->query('SELECT t0.id AS...')
#2 /code/vendor/doctrine/orm/lib/Doctrine/ORM/Persisters/Entity/BasicEntityPersister.php(1030): Doctrine\DBAL\Connection->executeQuery('SELECT t0.id AS...', Array, Array)
#3 /code/vendor/doctrine/orm/lib/Doctrine/ORM/Persisters/Entity/BasicEntityPersister.php(954): Doctrine\ORM\Persisters\Entity\BasicEntityPersister->getManyToManyStatement(Array, Object(Model\Article))
#4 /code/vendor/doctrine/orm/lib/Doctrine/ORM/UnitOfWork.php(2839): Doctrine\ORM\Persiste in /code/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php on line 90

我已经为此花了一天时间,试图找出哪里出了问题。我很怀疑,我可能会使用一个保留的MySQL单词,但在我的变量中没有找到任何。

我最终获得了完整的查询日志,直到出现异常。看起来,最有趣的查询不存在

mysqld, Version: 5.7.20 (MySQL Community Server (GPL)). started with:
Tcp port: 3306  Unix socket: /var/run/mysqld/mysqld.sock
Time                 Id Command    Argument
2017-11-25T23:46:52.327597Z        10 Connect   user@articlerepository_php_1.articlerepository_default on article_repository using TCP/IP
2017-11-25T23:46:52.334083Z        10 Query     SELECT t0.id AS id_1, t0.firstName AS firstName_2, t0.lastName AS lastName_3, t0.titleBefore AS titleBefore_4, t0.titleAfter AS titleAfter_5 FROM author t0
2017-11-25T23:46:52.342077Z        10 Query     SELECT t0.id AS id_1, t0.name AS name_2, t0.publication_id AS publication_id_3 FROM article t0
2017-11-25T23:46:52.348058Z        10 Quit