In my current project, I have to get some data in a column of one table and put them to the 2nd table. The first table data have been saved as hash as follows:
---
- werweqr
- test
- B1
- B2
- B3
- xvxczv
I write the following code in the migration file to add the data from the first table to the 2nd table. But the data are not sending from the first to second.
#scenario_response = ScenarioResponse.where("selected_barriers != ?", "");
#scenario_response.each do |p|
p.selected_barriers.each do |barrier|
Settings.test = barrier
# SelectedBarriers.create(:scenario_response_id => p.id, :barrier => barrier)
end
end
Can anyone please let me know if there's something wrong in my code.
If so how to fix it?
Thanks a lot
I don't think you need to call "each" on p.selected_barriers.Try removing the each and doing this:
Settings.test=p.selected_barriers.
I'm new to RoR too..According to me,the scenario_response is a collection that returns all instances that have the selected_barriers as "". Since you are doing an each on the collection, you will just have one selected_barriers item for each of them.
Please try this and let me know if I'm wrong.
Also you are not doing update_attributes.
Try doing Settings.update_attributes(params[:test]) after Settings.test = barrier .
Related
I've been digging around a little trying to figure out how I should locate the "tweet_id" in my #savedtweets table and then locate that same "tweet_id" in my #newtweets table from a controller, so far I'ved tried something like this;
CONTROLLER
#stweet = Savedtweet.find(params[:id])
#newtweet = Newtweet.where(:tweet_id => #stweet.tweet_id)
#newtweet.status = 'new'
#newtweet.save
Basically I need to change the string "saved" in my Newtweets table to "new" based on the current Savedtweet ID. I just can't figure it out. If I do the following in console;
#stweet = Savedtweet.first
#newtweet = Newtweet.where(:tweet_id => #stweet.tweet_id)
It finds the right one. I've got to be close just not there yet. :)
You could do:
Newtweet.find_by_tweet_id(#stweet.tweet_id).update_attribute(:status, 'new')
The reason your code isn't working is because Newtweet.where() returns an array of objects. It should be Newtweet.where().first, though Newtweet.find_by_tweet_id is the preferred method.
How do you work with the old values of a record being updated?
For instance in the following code block how would I run a query using the previous winner_id field after I determine that it has indeed changed?
if self.winner_id_changed?
old_value = self.changed_attributes
User.find(old_value)
#do stuff with the old winner....
end
An example output of self.changed_attributes would be:
{"winner_id"=>6}
Do I really have to convert this to a string and parse out the value in order to perform a query on it? old_value[:winner_id] doesn't seem to do anything.
Use where instead of find, and the following inject method on changes to generate the desired hash:
if self.winner_id_changed?
old_value = self.changes.inject({}) { |h, (k,v)| h[k] = v.first }
old_user = User.where(old_value)
#do stuff with the old user....
end
You can also use ActiveRecord dirty methods such as:
self.winner_id_was
to get specific attribute's old value. Full documentation may be found here.
I am missing the SQL out of this to Bulk update attributes by SKU/UPC.
Running EE1.10 FYI
I have all the rest of the code working but I"m not sure the who/what/why of
actually updating our attributes, and haven't been able to find them, my logic
is
Open a CSV and grab all skus and associated attrib into a 2d array
Parse the SKU into an entity_id
Take the entity_id and the attribute and run updates until finished
Take the rest of the day of since its Friday
Here's my (almost finished) code, I would GREATLY appreciate some help.
/**
* FUNCTION: updateAttrib
*
* REQS: $db_magento
* Session resource
*
* REQS: entity_id
* Product entity value
*
* REQS: $attrib
* Attribute to alter
*
*/
See my response for working production code. Hope this helps someone in the Magento community.
While this may technically work, the code you have written is just about the last way you should do this.
In Magento, you really should be using the models provided by the code and not write database queries on your own.
In your case, if you need to update attributes for 1 or many products, there is a way for you to do that very quickly (and pretty safely).
If you look in: /app/code/core/Mage/Adminhtml/controllers/Catalog/Product/Action/AttributeController.php you will find that this controller is dedicated to updating multiple products quickly.
If you look in the saveAction() function you will find the following line of code:
Mage::getSingleton('catalog/product_action')
->updateAttributes($this->_getHelper()->getProductIds(), $attributesData, $storeId);
This code is responsible for updating all the product IDs you want, only the changed attributes for any single store at a time.
The first parameter is basically an array of Product IDs. If you only want to update a single product, just put it in an array.
The second parameter is an array that contains the attributes you want to update for the given products. For example if you wanted to update price to $10 and weight to 5, you would pass the following array:
array('price' => 10.00, 'weight' => 5)
Then finally, the third and final attribute is the store ID you want these updates to happen to. Most likely this number will either be 1 or 0.
I would play around with this function call and use this instead of writing and maintaining your own database queries.
General Update Query will be like:
UPDATE
catalog_product_entity_[backend_type] cpex
SET
cpex.value = ?
WHERE cpex.attribute_id = ?
AND cpex.entity_id = ?
In order to find the [backend_type] associated with the attribute:
SELECT
backend_type
FROM
eav_attribute
WHERE entity_type_id =
(SELECT
entity_type_id
FROM
eav_entity_type
WHERE entity_type_code = 'catalog_product')
AND attribute_id = ?
You can get more info from the following blog article:
http://www.blog.magepsycho.com/magento-eav-structure-role-of-eav_attributes-backend_type-field/
Hope this helps you.
In rails 3, I would like to do the following:
SomeModel.where(:some_connection_id => anArrayOfIds).select("some_other_connection_id")
This works, but i get the following from the DB:
[{"some_other_connection_id":254},{"some_other_connection_id":315}]
Now, those id-s are the ones I need, but I am uncapable of making a query that only gives me the ids. I do not want to have to itterate over the resulst, only to get those numbers out. Are there any way for me to do this with something like :
SomeModel.where(:some_connection_id => anArrayOfIds).select("some_other_connection_id").values()
Or something of that nautre?
I have been trying with the ".select_values()" found at Git-hub, but it only returns "some_other_connection_id".
I am not an expert in rails, so this info might be helpful also:
The "SomeModel" is a connecting table, for a many-to-many relation in one of my other models. So, accually what I am trying to do is to, from the array of IDs, get all the entries from the other side of the connection. Basicly I have the source ids, and i want to get the data from the models with all the target ids. If there is a magic way of getting these without me having to do all the sql myself (with some help from active record) it would be really nice!
Thanks :)
Try pluck method
SomeModel.where(:some => condition).pluck("some_field")
it works like
SomeModel.where(:some => condition).select("some_field").map(&:some_field)
SomeModel.where(:some_connection_id => anArrayOfIds).select("some_other_connection_id").map &:some_other_connection_id
This is essentially a shorthand for:
results = SomeModel.where(:some_connection_id => anArrayOfIds).select("some_other_connection_id")
results.map {|row| row.some_other_connection_id}
Look at Array#map for details on map method.
Beware that there is no lazy loading here, as it iterates over the results, but it shouldn't be a problem, unless you want to add more constructs to you query or retrieve some associated objects(which should not be the case as you haven't got the ids for loading the associated objects).
Say I have a record called Post that has many comments.
Now I run the following code:
p = Post.new
p.comments.build(:title => 'great')
I would now like to locate that comment by its title.
If the record was saved, I could do something like
p.comments.find_by_title('great')
But since it isn't saved yet, that's going to return nil (because it actually runs an SQL query)
Is there a way to locate this record before it's saved?
Thanks!
comment = p.comments.build(:title => "great")
great_comment = p.comments.detect{|c| c.title == 'great'}
Just write:
new_comment = p.comments.build(:title => 'great')
and new_comment will be the newly added comment.
Or, you could do something like:
new_comments = p.comments.select{|x| x.new_record?}
which would give you an array with all the unsaved comments.