I have 4 entities one-to-many Message entity: @Entity @Table(name = "Messages") public class Message { ... @ManyToOne(cascade = CascadeType.ALL) @JoinColumn(name = "messagesounds_id") private Sound sound; @ManyToOne(cascade = CascadeTy
Is there a way to have a custom serialization for fields in rails, a method that runs when a field is saved and loaded to convert from/to a string which is what ultimately is saved on the database. Specifically what I want to do is have a field of ty
How can I perform a join operation on 2 tables while working in rails? Give a simple solution to perform search on joining 2 tables.You store copies of data in multiple tables/collections. In doing so, you avoid the need for JOINs and lookups needed
I am trying to make an autoincrement id field into a postgre DB in rails. I am trying to get the maximum id and then just add +1 and pass it down to create method. I am not quite sure what I am doing wrong, but if I have 4 projects and add the 5th on
This question already has an answer here: How to express a NOT IN query with ActiveRecord/Rails? 15 answers What I want to do is write a .where rails query that takes an array as an argument. I have a object Company, and what I want the query to do i
I have a mapping table referring to ids from two different tables. I would like to select the mapping table with each id being replaced by another field in the respective table. To be a little more explicit: there are three tables with two columns ea
in Sql Server 2005, I have a master table, and several other tables which are related to this master through several one to many relations. How can I find all tables and fields which are in relation with the primary key in the master table, on "many&
I need to join two tables to get the Reason_Descriptions for multiple fields from another table based on the Reason_Id. My problem is that I am not sure how to compare the field values. Table 1: Reason_Id, Reason_Description Table 2: Reason1_Id, Reas
Can I look around in a database with Django? I mean outputting a list of all tables, all fields in tables and all objects in a specific table? I know how to build models and lookup objects, but can I lookup fields in a preexisting database? I have a
I have "books" table in amazon-Dynamodb, which is having 287 items and 97kb in size. i tried to load my all data from books table through ruby on rails coding(controller). but its loading time is very slow. and sometimes it shows nothing because
So the question is pretty much all in the title. I was just wondering if there is and easy way to create a table and have a field for each day of the year without doing 365 entries. The reason I want this is make it easier for weekly, monthly and yea
I just updated from Rails 4.0.2 to Rails 4.1.2 and realized ActiveRecord includes have become unusably slow. What used to take just a view milliseconds now take almost 5 minutes. I join two tables Item and Keyword over a join table with has_and_belon
sql = DmozCategory.send(:sanitize_sql_array, ["INSERT INTO dmoz_categories (id, dmoz_category_title, dmoz_category_name, dmoz_category_description, created_at, updated_at, dmoz_category_lastupdate) VALUES (?, ?, ?, ?, NOW(), NOW(), ?)", result['
I have some Rails ActiveRecord code that looks like this: new_account_number = Model.maximum(:account_number) # Some processing that usually involves incrementing # the new account number by one. Model.create(foo: 12, bar: 34, account_number: new_acc