Trying to pull data from ActiveRecord::Assosiation

I have a rails app, with sale which has_may :line_items.
I’m trying to pull from the database if the line item are
express_production.
But it always return all the sales.

sls = Sale.in_between(Date.today - 30, Date.today).order(“ordered_on
DESC”)
@sales = sls.select do |sale|
sale.line_items.select{ |l| l.express_production }
end

But it return every sale even when they have express_production = false.

Could anyone help me.
Thanks

On Monday, April 14, 2014 10:18:32 AM UTC+1, Gustavo C. wrote:

But it return every sale even when they have express_production = false.

When none of a sale’s line items have express_prodiction set to true

then sale.line_items.select{ |l| l.express_production } will be [],
but that is still truthy to ruby so @sales will be set to all sales.

You could for example tack a .any? on the end to only select sales with
at
least one relevant line item.

You might also want to look into doing this filtering via the DB - at
the
moment you’ll be loading all of the line items for each sale (one sale
at
a time), which won’t be very fast.

Fred

On Monday, 14 April 2014 05:18:32 UTC-4, Gustavo C. wrote:

As Fred has pointed out, even when there aren’t any matching line_items
the
inner select here will still return a truthy [].

One way to do this with SQL might be: (I’m assuming express_production
is a
boolean column on the line_items table)

Sale.in_between(…).joins(:line_items).where(line_items: {
express_production: true }).order(…)

This should generate an INNER JOIN clause between sales and line_items.

–Matt J.