Exception or error: I am a newbie ,tried to google but I am unable to solve my query. Please help. I am trying to map two entities : PersonA and Person in my POJO class PersonC @Entity class PersonA{ String sample_field; } @Entity class Person{ String id; String name; } Above two are entities of …
Tag: join
php – Laravel Eloquent how to join on a query rather than a table?-ThrowExceptions
Exception or error: I want to achieve this in Laravel: SELECT * FROM products JOIN (SELECT product_id, MIN(price) AS lowest FROM prices GROUP BY product_id) AS q1 ON products.id = q1.product_id ORDER BY q1.lowest; I wrote this, but clearly there is something wrong: $products = new Product(); $products = $products->join( Price::whereNotNull(‘price’)->select(‘product_id’, DB::raw(‘min(price) as lowest’))->groupBy(‘product_id’), ‘products.id’, …
How can I join an array using Google Guava (Java)?-ThrowExceptions
Exception or error: I am trying to join int[] (array of int) using Google Guava’s Joiner class. Example: int[] array = { 1, 2, 3 }; String s = Joiner.on(“, “).join(array); // not allowed I checked StackOverflow and Google. There is no “one-liner” in foundation classes to convert int[] to Integer[] or List<Integer>. It always …
Join two arrays in Java?-ThrowExceptions
Exception or error: This question already has answers here: Closed 7 years ago. Possible Duplicate: How to concatenate two arrays in Java? I have two objects HealthMessage[] healthMessages1; HealthMessage[] healthMessages2; HealthMessage[] healthMessagesAll; healthMessages1 = x.getHealth( ); healthMessages2 = y.getHealth( ); How should I join the two objects, so I can return only one: return healthMessagesAll; …
Can Java 8 streams cause a O(1) memory reduction on unbounded data to become O(n) memory because of the underlying ForkJoin implementation-ThrowExceptions
Exception or error: I’ve written a streams implementation that performs four simple reductions (+ and <) on the lines of a file. At first I performed four streams, but I decided to write my own accumulator and combiner so that I could perform all four reductions in one stream. On small data sets (10,000,000 lines) …
php – mysql select/delete using join over four tables-ThrowExceptions
Exception or error: I have four tables (in [] are columns): users [id] products [id] productRatings [id,value,user,product] comments [id,product,user] I would like to select/and ultimately delete productRatings where there are no associated comment by the same user for that product. That is, if user has rated product but did not comment, that rating should be …
java – Hibernate HT_ Temporary Tables ON JOINED inheritance, Migration from Hibernate 3.4.0.GA To 5.1-ThrowExceptions
Exception or error: I’m trying to migrate an application from Hibernate 3.4.0.GA to Hibernate 5.1, and after complete the required changes on java code, when I deploy the application I’m watching how Hibernate is trying to create HT_ tables (global temporary), one for each @Inheritance annotated entity. Searching on Google I’ve found why the tables …
java – Join on different elements using Spring JPA Specifications and Hibernate-ThrowExceptions
Exception or error: I’m trying to build a JPA specification for a I18N implementation to be able to filter on a name. In the database I have translations for multiple languages. The thing is that most of the times only the default language is specified. So when someone requests the translation for a non default …
java – Is it bad practice to use default common fork/join pool with CompletableFuture for doing long blocking calls?-ThrowExceptions
Exception or error: Lets say I have a CompletableFuture which wraps a blocking call like querying a backend using JDBC. In this case, since I am not passing any executor service as a parameter to CompletableFuture.supplyAsync(), the actual blocking work of fetching the resources over backend should be done by a thread within the common …
java – Hibernate/JPA unidirectional OneToMany with join condition on constant value in source table-ThrowExceptions
Exception or error: I want to use Hibernate annotations to represent a unidirectional one-to-many relationship using a join. I want an added condition on the join so it only happens when a column in the source table (the “one”) is equal to a constant value. For example. SELECT * FROM buildings b LEFT JOIN building_floors …