I have two tables orders
, product_meta
that are as follows:
orders:
order_id product_id 1 45 1 46 2 46
product_meta:
product_id meta_key meta_value 45 price 1199 45 name GPU-1 46 price 1299 46 name GPU-2
I want a table like this:
order_id product_id product_name product_price 1 45 GPU-1 1199 1 46 GPU-2 1299 2 46 GPU-2 1299
The query that I have tried:
select o.order_id, o.product_id, pm.meta_value as 'product_name' from orders o join product_meta pm on pm.product_id = o.product_id AND pm.meta_key = 'name'
but this only works for one field(name
) so how can I modify this so as to include price and other meta values?
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Answer
One method is two joins:
select o.*, pmn.meta_value as product_name, pmp.meta_value as product_price from orders o left join product_meta pmn on pmn.product_id = o.product_id and pmn.meta_key = 'name' left join product_meta pmp on pmp.product_id = o.product_id and pmp.meta_key = 'price';
This uses left join
s so all orders will be included, even if the metadata is missing either name or price or both.