magento是基于Zend Framework的,所以底层用的还是zend的zend db
今天在分析Magento源代码的时候，在文件app/code/core/Mage/Catalog/model/Resource/Eav /Mysql4/Config.php 中追踪到下面的函数 getAttributesUsedInListing()
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public function getAttributesUsedInListing() { |
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$select = $this->_getReadAdapter()->select() |
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->from(array(’main_table’ => $this->getTable(’eav/attribute’))) |
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array(’additional_table’ => $this->getTable(’catalog/eav_attribute’)), |
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‘main_table.attribute_id = additional_table.attribute_id’, |
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array(’al’ => $this->getTable(’eav/attribute_label’)), |
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‘al.attribute_id = main_table.attribute_id AND al.store_id = ‘ . (int) $this->getStoreId(), |
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array(’store_label’ => new Zend_Db_Expr(’IFNULL(al.value, main_table.frontend_label)’)) |
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->where(’main_table.entity_type_id=?’, $this->getEntityTypeId()) |
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->where(’additional_table.used_in_product_listing=?’, 1); |
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– $sql = $select->assemble(); |
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return $this->_getReadAdapter()->fetchAll($select); |
Magento操 作数据库是在 Zend DB（Zend Framework）的基础上简单的做了下封装了。Zend DB 有自己的一套规则，来组合生成最终的SQL查询语句，可以看到上面的代码中有 from() join() joinLeft() where() 等函数，乱七八糟的一大堆东西，需要对 Zend DB的规则非常熟悉，才能知道实际执行的SQL语句，有没有办法直接打印出SQL语句？找了下，还真有，就是assemble()函数。在上面代码中最后 部分可以看到。顺被把SQL也附上来
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IFNULL(al.value, main_table.frontend_label) AS `store_label` |
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FROM `eav_attribute` AS `main_table` |
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INNER JOIN `catalog_eav_attribute` AS `additional_table` |
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ON main_table.attribute_id = additional_table.attribute_id |
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LEFT JOIN `eav_attribute_label` AS `al` |
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ON al.attribute_id = main_table.attribute_id AND al.store_id = 1 |
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WHERE (main_table.entity_type_id=’4′) |
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AND (additional_table.used_in_product_listing=1) |
Magento 中获取 Zend_Db_Select对象中的SQL语句
