I'm working on a task where I have to define a function that attaches something to a column in my DB, however I'm quite new and despite looking at the ActiveRecord documentation I don't appear to be able to grab the column I'm looking for.
For example, I have a table with many columns including 'State' and 'Phase', I was able to grab state with the following code:
CaseFileStatus.where(state: case_file.state).first
However I can't somehow manage to grab the 'Phase' column now, as shown below.
CaseFileStatus.where(state: "case_file.phase")
CaseFileStatus Load (2.5ms) SELECT "case_file_statuses".* FROM "case_file_statuses" WHERE "case_file_statuses"."state" = $1 [["state", "case_file.phase"]]
=> []
I'm sure it's a super basic error, but how should I be structuring this query?
If you need to query records based on the phase column, you should do something like this:
CaseFileStatus.where(phase: case_file.phase)
Related
I'm new to Rails and I would like to know if I can check if data already exists in my database while uploading new data from CSV. So far I haven't found this on the net.
I use a Postgres database. I don't know if I have to check it in Rails or in Postgres. In my database there are some columns like id, personal_id, cost_center. So I will check if one (or more) of my new data has the same personal_id with the the same cost_center while uploading.
How can I do this?
UPDATE
I've tried the solution of #huan son, it works but not the way I need it. So I tried different things and I think a SQL query is in my case the best choice.
DELETE FROM bookings WHERE id NOT IN (SELECT MIN(id) FROM bookings GROUP BY personal_id, wbs, date, hours, cost_center)
Booking.delete_all.where('id NOT IN (?)', Booking.select('MIN(id)').group(:personal_id, :wbs, :date, :hours, :cost_center).map(&:id))
My SQL query works like the way I want it but I don't know the right "translation" into rails because with the second code above my whole bookings table gets deleted
Solution
The solution for my problem is:
Booking.delete_all(['id NOT IN (?)', Booking.group(:personal_id, :wbs, :date, :hours, :cost_center).pluck('MIN(id)')])
Those are unique scopes.
You need to define those first in your database migration so postgres is making sure there is no double-value wie [key, key1, key2...]
add_index :table, [:personal_id, :cost_center_id], :unique => true
then you need to go into your rails-model and catch that uniqueness at validations.
validates_uniqueness_of :personal_id, :scope => :cost_center_id
with that, rails is querying every time before creating a object, the database and check if something with the unique-pair-values already exists. if so, its adding it to the #errors of the model, so the model can't be saved
You can use uniqueness validation, but in my experience when importing data from CSV, the problem is that if the item already exists, all the validation does is stop the record being saved. In most examples, you usually want to do something with the matched record. Therefore, I'd suggest you also look at find_or_initialize_by. This allows you to also update existing records from imported data.
So if you have Thing model with a name and cost for example, you may want to identify existing things by name, and update their costs. And create new things where no matching name exists. The following code would do that:
name, price = some_method_that_gets_name_and_price_from_csv
thing = Thing.find_or_initialize_by name: name
thing.price = price
thing.save
Also have a look at find_or_create_by which can be more suitable in some situations. I'd also still keep the validation of uniqueness in the model. I just wouldn't use validation to handle how the data was imported.
I have this structure in index:
{ details: {errors:[], warnings:[], results:[]}}
I want a query so that I can get the count of errors warnings and results for each record.
I was looking into the script filter on an aggregate, but the thing is I am already aggregating and I'm unsure on how to use the value count filter with this since I need to
1) Get the .length attribute of the array
2) When I do that I get an error saying no attribute like that exists
Can I get a sample query? I'm guessing it will somehow incorporate the script filter.
The best way to achieve this is the token count data type told in the below link
LINK - http://www.elastic.co/guide/en/elasticsearch/reference/1.4/mapping-core-types.html#token_count
You can couple this with multi fields to achieve an extra field per error , warning and results. This can be used in the query to view the count of elements.
I read about createCriteria, and kind of interested on how these works, and its usability in providing values for dropdown box.
So say, i have a table in the database, Resource table, where i have defined the table in the domain class called Resource.groovy. Resource table has a total of 10 columns, where 5 of it are
Material Id
Material description
Resource
Resource Id
Product Code
So using the createCriteria, and i can use just like a query to return the items that i want to
def resList = Resource.createCriteria().list {
and {
eq('resource', resourceInstance)
ne('materialId', '-')
}
}
Where in the above, i want to get the data that matches the resource = resourceInstance, and none of the materialId is equal to '-'.
I want to use the returned data from createCriteria above on my form, where i want to use some of the column on my select dropdown. Below is the code i used for my select dropdown.
<g:select id="resourceId" name="resourceId"
from="${resList}"
disabled="${actionName != 'show' ? false : true}" />
How do i make it so that in a dropdown, it only shows the values taken from column Product Code? I believe the list created using createCriteria returns all 10 columns based on the createCriteria's specification. But i only want to use the Product Column values on my dropdown.
How do i customize the data if in one of the select dropdown in my form, i wanted to show the values as "Resource Id - Resource Description"? The values are combination of more than 1 columns for one select dropdown but i don't know how to combine both in a single select dropdown.
I read that hql and GORM query are better ways of fetching data from table than using createCriteria. Is this true?
Thanks
First of all refer to the document for using select in Grails. To answer all questions:
Yes, the list to select from in the dropdown can be customized. In this case it should be something like from="${resList*.productCode}"
Yes, this can be customized as well with something like
from="${resList.collect { \"${it.resourceId} - ${it.resourceDesc}\" } }"
It depends. If there are associations involved in a domain then using Criteria will lead to eager fetches which might not be required. But with HQL one gets the flexibility of tailoring the query as needed. With latest version of Grails those boundries are minimized a lot. Usage of DetachedCriteria, where queries etc are recommended whereever possible. So it is kind of mixing and matching to the scenario under consideration.
(I tried posting this to the CFWheels Google Group (twice), but for some reason my message never appears. Is that list moderated?)
Here's my problem: I'm working on a social networking app in CF on Wheels, not too dissimilar from the one we're all familiar with in Chris Peters's awesome tutorials. In mine, though, I'm required to display the most recent status message in the user directory. I've got a User model with hasMany("statuses") and a Status model with belongsTo("user"). So here's the code I started with:
users = model("user").findAll(include="userprofile, statuses");
This of course returns one record for every status message in the statuses table. Massive overkill. So next I try:
users = model("user").findAll(include="userprofile, statuses", group="users.id");
Getting closer, but now we're getting the first status record for each user (the lowest status.id), when I want to select for the most recent status. I think in straight SQL I would use a subquery to reorder the statuses first, but that's not available to me in the Wheels ORM. So is there another clean way to achieve this, or will I have to drag a huge query result or object the statuses into my CFML and then filter them out while I loop?
You can grab the most recent status using a calculated property:
// models/User.cfc
function init() {
property(
name="mostRecentStatusMessage",
sql="SELECT message FROM statuses WHERE userid = users.id ORDER BY createdat DESC LIMIT 1,1"
);
}
Of course, the syntax of the SELECT statement will depend on your RDBMS, but that should get you started.
The downside is that you'll need to create a calculated property for each column that you need available in your query.
The other option is to create a method in your model and write custom SQL in <cfquery> tags. That way is perfectly valid as well.
I don't know your exact DB schema, but shouldn't your findAll() look more like something such as this:
statuses = model("status").findAll(include="userprofile(user)", where="userid = users.id");
That should get all statuses from a specific user...or is it that you need it for all users? I'm finding your question a little tricky to work out. What is it you're exactly trying to get returned?
I'm trying to get a "What's new" section working in my Rails app that takes into account new records created for various tables that don't share any relationships. The one thing they do have in common is that they all have a created_at field, which I'm going to use to determine if they're indeed "new" and then I'm wanting to sort the results by that common field. I tried doing this with Sunspot, but I couldn't figure out how to make use of the the result set returned from the Sunspot search...
For instance in my Uploads and Article models I have:
searchable do
time :created_at
end
and in my search action I'll do this:
#updates = Sunspot.search(Upload,Article) do
with(:created_at).greater_than(1.hour.ago)
end
Which does seem to return something, if I do an #updates.total it returns the number of records I was expecting to find. Beyond this I'm not sure how to actually make use of the records. What I'd like to do is send #updates to a view and determine the model type of each record and then proceed to print out the relevant information, i.e names, descriptions, parent/child record information (for instance upload.user.username).
I might be going at this all wrong, perhaps there's a better option than sunspot for the simple search I'm attempting to perform?
Refer readme for details of how to use the search results. The method you are looking for is "results", which will give you first 30 results, by default:
#updates.results # array of first 30 results