网格中的收集错误

Question

如果我删除这行var_dump代码，我的模块就会崩溃。为什么会这样呢。我的连接有什么问题吗？

    protected function _prepareCollection() {

    $collection = mage::getModel('faq/faq')->getCollection();
    $collection->getSelect()->joinLeft(array('s'=>'gagan_faq_creation'),
            'main_table.faq_id = s.faq_id');
    var_dump($collection->getData());

    $this->setCollection($collection);
    parent::_prepareCollection();
}

我得到了这个错误

QLSTATE[23000]: Integrity constraint violation: 1052 Column 'faq_id' in order clause is ambiguous
#0 C:\wamp\www\www.ubt.com\lib\Varien\Db\Statement\Pdo\Mysql.php(110): Zend_Db_Statement_Pdo->_execute(Array)
#1 C:\wamp\www\www.ubt.com\lib\Zend\Db\Statement.php(300): Varien_Db_Statement_Pdo_Mysql->_execute(Array)
#2 C:\wamp\www\www.ubt.com\lib\Zend\Db\Adapter\Abstract.php(479): Zend_Db_Statement->execute(Array)
#3 C:\wamp\www\www.ubt.com\lib\Zend\Db\Adapter\Pdo\Abstract.php(238): Zend_Db_Adapter_Abstract->query('SELECT `main_ta...', Array)
#4 C:\wamp\www\www.ubt.com\lib\Varien\Db\Adapter\Pdo\Mysql.php(419): Zend_Db_Adapter_Pdo_Abstract->query('SELECT `main_ta...', Array)

Answer 1

您正在从两个表(main_table和gagan_faq_creation)中选择faq_id，这就是为什么它会给出MySQL错误，因此需要为gagan_faq_creation.faq_id添加联盟。