内部联接和按日期过滤不工作抛出完整性约束违规错误 - Magento 1

Question

I am trying to make an inner join on two tables to get data. and it worked however when I search to get date from the table. I get an error saying

Integrity constraint violation: 1052 Column 'created_at' in where clause 
is ambiguous, query was: SELECT COUNT(*) FROM `sales_flat_order` AS 
`main_table`
INNER JOIN `sales_flat_order_item` ON main_table.store_id = 
sales_flat_order_item.store_id WHERE (`created_at` >= '2017-04-01'

This is my code

    $collection = Mage::getModel('sales/order')->getCollection();

    $collection->addFieldToFilter('created_at');
    $collection->getSelect()->join("sales_flat_order_item", 
    "main_table.store_id = sales_flat_order_item.store_id", 
    array('name','sku','order_id','quantity'));

Answer 1

You can try something like this

$collection = Mage::getModel('sales/order')->getCollection();
$collection->addFieldToFilter('main_table.created_at', '2017-04-01');
$collection->getSelect()->join("sales_flat_order_item",
    "main_table.store_id = sales_flat_order_item.store_id",
    array('name','sku','order_id','qty_ordered'));

But your join looks weird maybe it would be better to use sales_flat_order.entity_id = sales_flat_order_item.order_id then store_id

What exactly do you try to get by that select?

Please, describe your task.