I have a table called audits which has a column 'changes' storing data in the form of hash
I would like to retrieve all entries with the following conditions:
- auditable_type = 'Expression'
- action = 'destroy'
- changes = { :EXP_SUBMISSION_FK =>'9999992642'}
I first tried the following code which returns me with nothing:
#deleted_history = Audit.find(:all, :conditions => ["auditable_type =? AND action = ? AND changes = ?",'Expression', 'destroy' , { :EXP_SUBMISSION_FK =>'9999992642'} ])
I then tried the following code which retrieves all entries in the 'audits' table with auditable_type = 'Expression' and action = 'destroy'.
I then loop through the resultset and discards all entries where EXP_SUBMISSION_FK is not equal to 9999992642. The code below returns me 5 entries/records
#deleted_history = Audit.find(:all, :conditions => ["auditable_type =? AND action = ?",'Expression', 'destroy' ])
#deleted_history.each do |test|
if test.changes['EXP_SUBMISSION_FK'] != 9999992642
#deleted_history = #deleted_history.reject { test }
end
end
I would like to know where did I go wrong with the first code example and whether there is a way of retrieving all entries with the aforementioned conditions in a much simpler way.
Thanks a lot for your help.
i'd do:
#deleted_history.select!{|hist| hist.changes['EXP_SUBMISSION_FK'] == '9999992642'}
One potential cause of failure is that you're looking for 9999992642 but you state before the value is '9999992642'
You just use something like below. I am storing element_values as a hash and i am selecting records based on the key/value pair.
scope :find_by_field_values, lambda {
|field_name, field_value|
(where("element_values like ?", "%\"#{field_name}\":\"%#{field_value}%"))
}
just try this based on your scenario.
Related
I am quite new to Ruby and could not find an appropriate answer to my questions. Let's say I have hash named
users_hsh = {}.
I am looping through all of my users in the DB and creating the following.
users.each do |user|
users_hsh[user.full_name] = {
completed_activities: some_integer_value,
active_activities: some_integer_value,
future_activities: some_integer_value
}
end
Now, I created a new hash named
total_sum_not_zero_user_hsh = {}.
I want to loop over all of the users in the users_hsh and check for each user if the total sum of completed_activities + active_activities + future_activities does not equal 0 and if this condition holds, I want to add this user to total_sum_not_zero_user_hsh. I have done the following but seems that this does not work.
users_hsh.each do |usr|
if usr.values.sum != 0
total_sum_not_zero_user_hsh[usr] = {
completed_activities: some_integer_value,
active_activities: some_integer_value,
future_activities: some_integer_value
}
end
end
What am I doing wrong? Thanks in advance!
Let's use your example of:
users_hash = {
"Elvin Jafarli" => {
completed_activities: 10,
active_activities: 2,
future_activities: 0
}
}
Think carefully about what your data structure actually is: It's a hash that maps the user name to some user attributes. If you loop through these values, you don't just get a usr, you get back precisely this mapping.
It's helpful to name your variables descriptively:
users_hsh.each do |user_name, user_attributes|
if user_attributes.values.sum != 0
# ...
end
end
With your attempt, you would have seen an error like this: NoMethodError: undefined method 'values' for #<Array:0x00007fe14e22f538>. What happened is that each usr was actually an Array such as:
["Elvin Jafarli", {completed_activities: 10, active_activities: 2, future_activities: 0}]
I have a Convo table and a GroupMeeting table that both are associated with a Msg table.
I want to find all the instances where the current_user has convos or group_meetings with msgs, combine the two, and then show both together to the user in order of the last msg.created_at
Here I have defined both:
#convos = Convo.includes(:msgs).where("sender_id = ? OR recipient_id = ?", current_user, current_user).where.not(:msgs => { :id => nil }).merge(Msg.order(created_at: :desc))
#group_meetings = current_user.group_meetings.includes(:msgs).where.not(:msgs => { :id => nil }).merge(Msg.order(created_at: :desc))
And then combined them together:
#convos = #convos + #group_meetings
What I can't figure out is how to now sort them by msg.created_at
I have tried the following:
#convos = (#convos + #group_meetings).sort_by(&:"#{msg.created_at}")
#convos.order('msg.created_at DESC')
These all seem to be server-side sorting though. How can I sort these based off the join table, after the array has been created?
Please let me know if I need to supply any other details. Thank you!!
You can try the following:
(#convos + #group_meetings).sort_by { |item| item.msgs.minimum(:created_at) }
I have two queries, I need an or between them, i.e. I want results that are returned by either the first or the second query.
First query is a simple where() which gets all available items.
#items = #items.where(available: true)
Second includes a join() and gives the current user's items.
#items =
#items
.joins(:orders)
.where(orders: { user_id: current_user.id})
I tried to combine these with Rails' or() method in various forms, including:
#items =
#items
.joins(:orders)
.where(orders: { user_id: current_user.id})
.or(
#items
.joins(:orders)
.where(available: true)
)
But I keep running into this error and I'm not sure how to fix it.
Relation passed to #or must be structurally compatible. Incompatible values: [:references]
There is a known issue about it on Github.
According to this comment you might want to override the structurally_incompatible_values_for_or to overcome the issue:
def structurally_incompatible_values_for_or(other)
Relation::SINGLE_VALUE_METHODS.reject { |m| send("#{m}_value") == other.send("#{m}_value") } +
(Relation::MULTI_VALUE_METHODS - [:eager_load, :references, :extending]).reject { |m| send("#{m}_values") == other.send("#{m}_values") } +
(Relation::CLAUSE_METHODS - [:having, :where]).reject { |m| send("#{m}_clause") == other.send("#{m}_clause") }
end
Also there is always an option to use SQL:
#items
.joins(:orders)
.where("orders.user_id = ? OR items.available = true", current_user.id)
You can write the query in this good old way to avoid error
#items = #items.joins(:orders).where("items.available = ? OR orders.user_id = ?", true, current_user.id)
Hope that helps!
Hacky workaround: do all your .joins after the .or. This hides the offending .joins from the checker. That is, convert the code in the original question to...
#items =
#items
.where(orders: { user_id: current_user.id})
.or(
#items
.where(available: true)
)
.joins(:orders) # sneaky, but works! 😈
More generally, the following two lines will both fail
A.joins(:b).where(bs: b_query).or(A.where(query)) # error! 😞
A.where(query).or(A.joins(:b).where(bs: b_query)) # error! 😞
but rearrange as follows, and you can evade the checker:
A.where(query).or(A.where(bs: b_query)).joins(:b) # works 😈
This works because all the checking happens inside the .or() method. It's blissfully unaware of shennanigans on its downstream results.
One downside of course is it doesn't read as nicely.
I ran into the same issue, however the code was defined in a different place and was very difficult to change directly.
# I can't change "p"
p = Post.where('1 = 1').distinct # this could also be a join
And I needed to add an or statement to it
p.or(Post.where('2 = 2'))
The following code won't raise an error, because it has distinct like the initial relationship.
p.or(Post.where('2 = 2').distinct)
The problem with it it that it only works as long as you know the relationship. It may or not have a join, or distinct.
This works regardless of what the relationship is:
p.or(p.unscope(:where).where('2 = 2'))
=> SELECT DISTINCT `posts`.* FROM `posts` WHERE ((1 = 1) OR (2 = 2))
It occurs when you try to combine two multi-active records of the same type, but one of them has a joins value or an includes value, or in your case a reference value, that the other does not.
Therefore we need to match the values between them, and I found a general way to do this without knowing the actual values in advance.
items_1 = #items.joins(:orders)
.where(orders: { user_id: current_user.id})
items_2 = #items.where(available: true)
.joins(items_1.joins_values)
.includes(items_1.includes_values)
.references(items_1.references_values)
#items = items_1.or(items_2)
just solve it!
def exec_or_statement(q1, q2)
klass = q1.klass
key = klass.primary_key
query_wrapper_1 = {}
query_wrapper_1[key] = q1
query_wrapper_2 = {}
query_wrapper_2[key] = q2
klass.where(query_wrapper_1).or(klass.where(query_wrapper_2))
end
query_1 = #items.where(available: true)
query_2 =
#items
.joins(:orders)
.where(orders: { user_id: current_user.id})
exec_or_statement(query_1, query_2)
I have a call to ActiveRecord in my controller as so:
#configurations = EmailConfiguration.where(customer_id: '1', email_template: '1')
This will return all EmailConfigurations that have the correct parameters. Each record has a field_id and a the_value. I want to display the value in the view:
#configurations.where(field_id: 1).the_value
What do I need to add to the view to select a certain record within the collection that is returned by the database?
You can use select for a quick filter on arrays
#configurations.select {|c| c.field_id == 1}
that will return all collections with field_id = 1. If you know there is only one, you could chain it for a direct output:
#configurations.select {|c| c.field_id == 1}.first.the_value
#configurations.where(field_id: 1)
returns a collection of objects(array) even if there is only one result. If you would like to show only one you can do as suggested above:
#configurations.select {|c| c.field_id == 1}.first.the_value
If you want to show all of the "the_values" you can do
field_1_configs = #configurations.select do |c| c.field_id == 1
end
field_1_configs.map{|config| config.the_value }
my actual code looks like this
user_lesson = self.where("worked = ? AND passed = ?", true, false).order("lessons.sort")
But it doesn't work ... error is:
undefined method `where' for #<Membership:0x000000059f22e8>
.. I've tried it this way:
user_lesson = Membership.joins("user_lessons").where("id = ? AND worked = ? AND passed = ?",self.id, true, false).order("lessons.sort")
But then I got this error:
Unknown table 'memberships': SELECT `memberships`.*
FROM `memberships` user_lessons
WHERE (id = 4 AND worked = 1 AND passed = 0)
ORDER BY lessons.sort
How should it look like correctly?
Original Query
user_lesson = self.user_lessons.find :first,
:include => [:lesson],
:conditions => ["worked = ? AND passed = ?", true, false],
:order => "lessons.sort"
This is because the where method is defined at the class level rather than the instance level. In your second example (where you're doing Membership.joins) you are doing the right thing by calling joins and where on the Membership class rather than on an instance of that class. The reason you get an error with that second example is probably because you need to run your migrations to create the memberships table (if you have no migration you'll need to create one).