Optimizing Rails Code

Rails
1

Hello,

I often find myself creating and retrieving ActiveRecord objects that
barely get used, unaware of perhaps a better way of database
interaction within Rails. Are there more efficient ways to do some of
the following things:

Ex 1:
Supplier.find(supplierid).update_attributes(:num_products =>
total, :ship_fee => SHIPPING_FEE)

Ex 2:
item = Product.find(
:first,
:conditions => [“supplierid = #{supplierid} AND sku =
‘#{attributes[:sku]}’”]
)
attributes[:last_change] = Date.today if product_changed(item,
attributes)
attributes[:last_update] = Date.today
item.update_attributes(attributes)

Ex 3:
image = SupplierImage.new(
:productid => productid,
:mid => IMAGE_MACHINE,
:filename => filename,
:alt => prodname,
:supplier_url => url
)
image.save

Thanks!

2

In the third instance, you could just use “create” instead of
“new/save”. Doesn’t save you many lines (1) and doesn’t really make
it any more efficient (all that does is call new/save), but hey at
least it looks better. :slight_smile:

–Jeremy

On 7/17/07, Matt W. [email protected] wrote:

total, :ship_fee => SHIPPING_FEE)
item.update_attributes(attributes)

Thanks!

–
http://www.jeremymcanally.com/

My free Ruby e-book:
http://www.humblelittlerubybook.com/book/

My blogs:

http://www.rubyinpractice.com/

3

Ex 1:
Supplier.find(supplierid).update_attributes(:num_products =>
total, :ship_fee => SHIPPING_FEE)

Supplier.update(supplierid, :num_products => total, :ship_fee =>
SHIPPING_FEE)

Not clear about this one.

-Pratik

http://m.onkey.org

4

Matt W. wrote:

Ex 2:
item = Product.find(
:first,
:conditions => [“supplierid = #{supplierid} AND sku =
‘#{attributes[:sku]}’”]
)

You are leaving yourself open to SQL injection here. You should always
use :conditions => [‘supplierid = ? AND sku = ?’, supplierid,
attributes[:sku]]

Also, you don’t need to do a find if all you want to do is to update an
attribute, checkout update_all for that.

–
Cheers,

  • Jacob A.
5

On 7/17/07, Pratik [email protected] wrote:

Ex 1:
Supplier.find(supplierid).update_attributes(:num_products =>
total, :ship_fee => SHIPPING_FEE)

Supplier.update(supplierid, :num_products => total, :ship_fee => SHIPPING_FEE)

This saves you a line of code. If all you want to do is update some
fields quickly, use update_all, though it’s closer to raw sql.

Supplier.update_all [‘num_products = ?, ship_fee = ?’, total,
SHIPPING], [‘id=?’, supplierid]

Though no validations or callbacks are called on your model.

Ex 2:
item = Product.find(
:first,
:conditions => [“supplierid = #{supplierid} AND sku =
‘#{attributes[:sku]}’”]
)
attributes[:last_change] = Date.today if product_changed(item,
attributes)
attributes[:last_update] = Date.today
item.update_attributes(attributes)

Same thing, all you’re doing is updating a few timestamps on a record.

–
Rick O.
http://lighthouseapp.com
http://weblog.techno-weenie.net
http://mephistoblog.com