sql,ruby-on-rails,ruby,ruby-on-rails-4,activerecord , rails has_many at least one children has the value
rails has_many at least one children has the value
Question:
Tag: sql,ruby-on-rails,ruby,ruby-on-rails-4,activerecord
Let say I have a Group of Users and User has a enum, which described it's mood.
class Group < AR::Base
has_many :users
class User < AR::Base
belongs_to :group
enum mood: %i(good bad ugly)
How can I find all groups, where at least one User has the good mood?
Which index should I add for optimizing this query?
Answer:
You can use joins method.
Group.joins(:users).where("users.mood = ?", User.moods[:good])
You can add this into your migration
add_index :users, :group_id
Related:
sql,ms-access,ms-access-2007
Here is my SQL query which returns number of days by subtracting current date from specified date and returns exact as i need, but in addition i want to add 1 to result if current time passes 14:30 or 2:30. My query SELECT reservations.customerid, DateDiff("d",reservations.checkin_date,Now()) AS Due_nights FROM reservations Am...
ruby-on-rails,ruby,ruby-on-rails-4,twitter
I have a model named Tweet. The columns of the Tweet model are: -id -content -user_id -picture -group -original_tweet_id Every tweet can have one or multiple retweets. The relation happens with the help of original_tweet_id. All the tweets have original_tweet_id nil , whilst the retweets contain the id of the...
sql,sql-server
I have this issue, I need your help: EmpNo Shift_Date Shift1 shift2 stamp_Date stamp_Time stamp_Type 426 2015-04-12 A 2015-04-12 10:09:00.000 I 426 2015-04-15 B C 2015-04-15 23:46:00.000 I 426 2015-04-15 B C 2015-04-15 23:45:00.000 O 426 2015-04-16 OF 2015-04-16 07:02:00.000 O 426 2015-04-17 A 2015-04-17 07:34:00.000 I 426 2015-04-18 A...
ruby-on-rails,ruby,enums
I need to do something like this: class PlanetEdge < ActiveRecord::Base enum :first_planet [ :earth, :mars, :jupiter] enum :second_planet [ :earth, :mars, :jupiter] end Where my table is a table of edges but each vertex is an integer. However, it seems the abvove is not possible in rails. What might...
sql,tsql,recursion,order,hierarchy
I am trying (and failing) to correctly order my recursive CTE. My table consists of a parent-child structure where one task can relate to another on a variety of different levels. For example I could create a task (this is the parent), then create a sub-task from this and then...
sql,sql-server,sql-server-2008
I am getting the following error message when I am trying to do replace null to zero. The column name "jan" specified in the PIVOT operator conflicts with the existing column name in the PIVOT argument. Query below: select * from(select isnull(jan,0),isnull(feb,0),sum(data) as amount )as p pivot( sum(amount) for month...
ruby-on-rails,activerecord
On the group index page I display a listing of group discussions and a form to create a new discussion. class Group < ActiveRecord::Base has_many :discussions end class Discussion < ActiveRecord::Base belongs_to :user belongs_to :group end Controller: class DiscussionsController < ApplicationController def index @group = Group.find(params[:group_id]) @discussion = current_user.discussions.build({group_id: @group.id})...
mysql,sql
I've the following table in my PHPMYADMIN The desired output is headline impressions clicks Buy A new Iphone ...
ruby-on-rails,ruby,ruby-on-rails-4
I am having trouble building a controller concern. I would like the concern to extend the classes available actions. Given I have the controller 'SamplesController' class SamplesController < ApplicationController include Searchable perform_search_on(Sample, handle: [ClothingType, Company, Collection, Color]) end I include the module 'Searchable' module Searchable extend ActiveSupport::Concern module ClassMethods def...
ruby-on-rails,arrays
I have to pass a array of food_item_ids in my order_controller. Every order will have many food_items. How can I pass these food_items_id as an array in strong parameters. orders_controller.rb def create @order = Order.new(order_params) if @order.save render :json, @order, status:201, location: [:api, @order] else render :json, { errors: @order.errors...
mysql,sql,database
I have this mysql table structure: ------------------------------------ | item_id | meta_key | meta_value | ------------------------------------ 159 category Bungalow 159 location Lagos 159 price 45000 160 category Bungalow 160 location Abuja 160 price 53500 ... 350 category Bungalow 350 location Lagos 350 price 32000 What I'd like to do is select...
ruby-on-rails
I'm setting up permissions for each user to determine what access they have to certain data. I have a user model and a permission model that is set up with a has_many and belongs_to association like so: app/models/permission.rb class Permission < ActiveRecord::Base has_many :users end app/models/user.rb class User < ActiveRecord::Base...
sql,oracle,oracle11g
SELECT * FROM FirstTable WHERE RowProcessed = 'N' AND ( CASE WHEN EXISTS(SELECT top 1 FROM SecondTable) THEN 1 ELSE EXISTS( SELECT SecondTable.RowProcessed FROM SecondTable WHERE FirstTable.Key = SecondTable.Key AND SecondTable.RowProcessed = 'Y' ) END ) AND OtherConditions Case When then else in where clause. Not sure about the syntax....
sql,variables,coding-style,condition
I am a beginner to SQL, and I am having trouble getting rid of repeated code. I have a condition "AccountId=20" that I use twice in a SQL query. The SQL looks something like: DELETE FROM Table_A WHERE FunctionId IN (Select FunctionId FROM Table_B WHERE AccountId=20); DELETE FROM Table_B WHERE...
c#,sql,sql-server,database
I have two tables, A and B, in a dataset in SQL Server; I have created a connection to the dataset in a c# project in visual studio. How can I create a foreign key ( A is the parent) between my two tables ? I want to create the...
php,sql,database
I am creating a very small, simple CRM for a company, they require the function to be able to view the last 25 orders via the dashboard. The orders are added via a Order-add form within the CRM. When adding the following code to the CRM I get an error:...
ruby-on-rails,ruby-on-rails-4,mongoid,embedded-documents
I'm trying to create a Mongoid N-N reference association between two embedded documents in Rails 4 however I'm finding it difficult to get my head round how this is done. I started by adding the HABTM association to the relevant models below (Track and Option) but of course I'm getting...
sql,sql-server-2012
I've a database value that when inserted into a SQL variable, shows with question mark at the end !! can't find a reason?! declare @A varchar(50) = 'R2300529' select @A Results: R2300529? any explanation? i'm using SQL server 2012....
php,sql
When I use mysql_real_escape_string in my localhost and I output the result of html in a table I have no problem. But when I use it on my server it outputs even the \ This is how I use it: $_GETVARS['txtEmpNum'] = mysql_real_escape_string($_GETVARS['txtEmpNum']); $_GETVARS['txtLName'] = mysql_real_escape_string($_GETVARS['txtLName']); $_GETVARS['txtFName'] = mysql_real_escape_string($_GETVARS['txtFName']); $varSQL...
sql,sql-server
I have values like below I need to take only the thousand value in sql. 38,635.123 90,232.89 123,456.47888 I need to take result as below. 635 232 456...
sql,tsql
I have the following Group By SQL: SELECT s.Login_Name, COUNT(s.s1CIDNumber) FROM [dbSuppHousing].[dbo].[tblSurvey] s group by s.Login_Name I want to know how I can join this result set to another table(tblUsers) to add user_id to the result set (tblSurvey and tblUsers have 1-1 relationship on Login_Name) I tried the following: Select...
sql,sql-server,sql-server-2008
I have Two tables first us IMG_detail S.NO Title 1 women holding stack of gifts 2 Rear view of a man playing golf 3 Women holding gifts 4 Close-up of a golf ball on a tee 5 Businessman reading a newspaper and smiling and Second is tbl_NoiceWords SN Key 1...
mysql,ruby-on-rails,rdbms
I see add_index ~ unique: true statement in schema.rband think uniqueness is constraint for table, not for index.Using index is one of way realizing uniqueness, Programmer should not designate to the RDBMS "how" and index quicken searching but take costs inserting. In fact, is there another way to keep uniqueness...
mysql,sql
[Aim] We would like to find out how often an event "A" ocurred before time "X". More concretely, given the dataset below we want to find out the count of the prior purchases. [Context] DMBS: MySQL 5.6 We have following dataset: user | date 1 | 2015-06-01 17:00:00 2 |...
php,mysql,sql,mysqli
This is the query I'm using to count how many events are booked for each category of bookings. SELECT Categories.name, count(case when locations.name ='loc 1' then 1 end) as Location1, count(case when locations.name ='loc 2' then 1 end) as Location2, count(case when locations.name ='loc 3' then 1 end) as Location3,...
mysql,sql
Basically i want to inner join 3 tables and the case is understood by the query itself as follows. Tables: A has 2 columns column 1 and column 2 B has 2 columns column 3 and column 4 C has 3 columns column 5,column 6 and column 7 Query: select...
mysql,sql,select,sum
I want to select the sum of values of my_field. The unit of my_field is in seconds. I don't want to exceed 24 hours, so when it exceeds 24 hours, I want it to select 24*60*60 = 86400. SELECT IF(SUM(my_field) > 86400, 86400, SUM(my_field)) ... This solution doesn't seem to...
python,sql,matplotlib,plot
from sqlalchemy import create_engine import _mssql from matplotlib import pyplot as plt engine = create_engine('mssql+pymssql://**:****@127.0.0.1:1433/AffectV_Test') connection = engine.connect() result = connection.execute('SELECT Campaign_id, SUM(Count) AS Total_Count FROM Impressions GROUP BY Campaign_id') for row in result: print row connection.close() The above code generates an array: (54ca686d0189607081dbda85', 4174469) (551c21150189601fb08b6b64', 182) (552391ee0189601fb08b6b73', 237304) (5469f3ec0189606b1b25bcc0',...
ruby-on-rails,ruby,rack,multipart
Rack::Utils.multipart_part_limit is set to 128 by default. What purpose does the value have and what effect does it have within the Rails system?...
ruby-on-rails,ruby,rest,activerecord,one-to-many
I'm creating a rails application that is a backend for a mobile application. The backend is implemented with a RESTful web API. Currently I am trying to add gamification to the platform through the use of badges that can be earned by the user. Right now the badges are tied...
sql,awk,sqlite3
I have to parse very big (abt 40Gb) text files(logs) very often. Usually AWK/grep is enough for my needs, but logs are growing and now I'm curious whether sqlite3 will allow me to do the same things more efficiently. I chosen sqlite for my tests as it installed out-of-the-box (SQLite...
ruby-on-rails,ruby,ruby-on-rails-4,model-view-controller
I have a navigation bar included in application.html.erb. Because for some pages, such as the signup page, I need to place additional code inside the navigation bar, I have excluded those pages for showing the navigation bar through application.html.erb and instead included it in their respective view pages. See code...
sql,sql-server,join
I have two 2 table t1(years int, numOfppl int), t2(years int, numOfppl int). t1 contains years between 2001 and 2010 , t2 contains years between 2003-2005 and 2007-2010 I want to query a result like that t1.years t1.numOfppl t2.yeras t2.numOfppl 2001 7 null null 2002 6 null null 2003 4...
ruby-on-rails,ruby-on-rails-4
I'm trying to do something that I imagine to be very basic, but I'm very new to Rails and am not sure what sure what I'm doing wrong. I've gone through several tutorials and searched for an answer and can't find what the issue is. Would appreciate any help! I've...
sql,sql-server,tsql,variables,like
I'm currently working on a report that shows me all post codes covered by our sales team. Each team covers over 100 post codes. What i would like to do is create a report that brings back the clients within the post code. Currently my code looks like this. SELECT...
sql,sqlite
I have a table t as follows: CREATE TABLE t( id INTEGER PRIMARY KEY AUTOINCREMENT, date TEXT, a TEXT, b TEXT ); Sample Data 1|2015-06-15|a1 15|b1 15 2|2015-06-15|a2 15|b2 15 3|2015-06-16|a1 16|b1 16 4|2015-06-16|a2 16|b2 16 5|2015-06-17|a1 17|b1 17 6|2015-06-17|a2 17|b2 17 I want to select all values of a...
sql,sql-server,tsql,sql-server-2012
If i have a resultset like this for example (just a list of numbers) : 1,2,3,4,5,6,7,8,9,10,11 and I would like to add a grouping column so i can group them per 4 like this : 1,1,1,1,2,2,2,2,3,3,3 (The last one in this examle does not have a forth element, so that...
sql,sql-server,tsql
Can someone tell me how this is an exclude? Assuming that tableID is auto generated and in columnY there can be value of 0 or 1. This statement should exclude everything were columnY has a value of 1. SELECT * FROM [table].[dbo].[one] AS t1 LEFT JOIN [table].[dbo].[one] AS t2 ON...
mysql,sql,sql-server,database,stored-procedures
So I am working with a database where I will be purging various tables that contain rows that are older than 30days. I have fairly limited knowledge of SQL and wanted to know if there was a certain way to select the row that will be purged and the rows...
ruby-on-rails,ruby,ruby-on-rails-4,activerecord
In Rails, ActiveRecord objects, attributes are accessible via method as well as through Hash. Example: user = User.first # Assuming User to be inheriting from ActiveRecord::Base user.name # Accessing attribute 'name' via method user[:name] # Attribute 'name' is accessible via hash as well How to make instance variables accessible through...
ruby-on-rails,ruby,authentication
I am building a small API that uses basic authentication. What I have done, is that a user can generate a username and password, that could be used to authenticate to the API. However I have discovered that it is not working 100% as intended. It appears that a request...
sql,sql-server,sql-server-2008
I am creating a key-wording module where I want to search data using the comma separated words.And the search is categorized into comma , and minus -. I know a relational database engine is designed from the principle that a cell holds a single value and obeying to this rule...
sql
I couldn't find the answer to my specific question anywhere. Is it possible to select from two different views? For example my code looks something like this right. select view1.col1, view1.col2, view1.col3 from dbo.view1 inner join ~~~~~ inner join ~~~~~ but I want to include a column from a different...
ruby-on-rails,arrays,ruby,multidimensional-array
seating_arrangement [ [:first, :second, :none], [:first, :none, :second], [:second, :second, :first], ] I need to copy this array into new array. I tried to do it by following code: class Simulator @@current_state def initialize(seating_arrangement) @@current_state = seating_arrangement.dup end But whenever I am making any changes to seating_arrangement current_state changes automatically....
sql,sql-server
I have the following DB table called messages with columns: thread_id, sender_id, receiver_id, date Example: +-----------+------------+-------------+-------------+ | thread_id | sender_id | receiver_id | date | +----------------------+-----------+-----------------+ | 1 | 1 | 2 | 11/06/2015 | | 1 | 2 | 1 | 14/06/2015 | | 1 | 1 | 2...
ruby-on-rails,gem,activeadmin
I have one poll table having with question filed and each question have 4 answer which is has_many relation ship with answer table class Poll < ActiveRecord::Base has_many :answer end My answer model class Answer < ActiveRecord::Base belongs_to :poll, :class_name => "Poll", :foreign_key => "question_id" end My active admin form...
ruby-on-rails,activerecord,callback
Although this can be accomplished as follows: class Model < ActiveRecord::Base around_destroy :callback def callback puts 'callback1 before yield' puts 'callback2 before yield' yield puts 'callback1 after yield' puts 'callback2 after yield' end end But I wish to do the following: class Model < ActiveRecord::Base around_destroy :callback1, :callback2 def callback1...
sql,sql-server
I have a query to display the year value from a table and default the current year. select distinct year(startdate) as syear, year(startdate) as eyear, 1 as sOrder from [TTS].[dbo].[Class] where year(startdate) <> year(getdate()) union all select year(getdate()) as syear, year(getdate()) as eyear, 0 as sOrder order by sOrder asc,...
ruby-on-rails,email,mailer
On my local host, I followed this article made a mail server and it works well. https://www.digitalocean.com/community/tutorials/how-to-install-postfix-on-centos-6 I want to develop a mailer feature with rails framework. Here are my settings: # mailer config.action_mailer.default_url_options = { :host => 'example.com' } config.action_mailer.delivery_method = :smtp config.action_mailer.smtp_settings = { address: 'localhost', port: 25,...
ruby-on-rails
I want to find a record from database in ruby on rails by using find_by with two fields. How can I accomplish it?