Magento Query Patterns is a library of sub-query classes for everyday use in Magento queries.

##Installation

Download the latest edition and extract it to Magento's base folder. The folder /lib/Knectar will be created. Be careful to preserve the folder arrangement so that Magento's autoloader can work accurately.

##Usage

Query patterns are sub-queries and can be used anywhere Zend select objects can. For convenience, the static method enhance is best.

// this example adds a `product_tags` column
$collection = Mage::getResourceModel('catalog/product_collection');
Knectar_Select_Product_Tags::enhance($collection->getSelect(), 'tags', 'tags.product_id=e.entity_id');

foreach ($collection as $product) {
    echo $product->getProductTags(), "\n";
}

The parameters of enhance are:

• $select Must be an instance of Varien_Db_Select.
• $tableName The sub-query will be joined as this table. Must be unique for $select.
• $condition The ON clause for a JOIN statement, it will use the table name.
• $columns (Optional) Associative array of column names to add to the field list.
• $type (Optional) One of the Zend_Db_Select::*_JOIN constants, the default is LEFT_JOIN.

Some classes provide more specific convenience functions, see the wiki for references.

##Distribution

This library is shared under the MIT license, meaning you are free to use it for any purpose and free to include it in your extensions. Because other extension authors might like to use the same library please do not modify any source files directly, instead fork this project and submit your modifications that way. Alternatively, to avoid confusion, extend the classes with your own in a namespace other than Knectar_.