Can JPA query return map?

Posted on By Aman Kelley

Can JPA query return map?

There is no standard way to get JPA to return a map. Iterating manually should be fine. The time to iterate a list/map in memory is going to be small relative to the time to execute/return the query results.

How do I return a key value from a SQL map?

Take a look at the following question, that addresses the issue: How to fetch hibernate query result as associative array of list or hashmap. For instance, the following HQL: select new map(perm.id as pid, perm.name as pname) from Permission perm will return a List of Map s, each one with keys “pid” and “pname”.

What is difference between HQL and SQL?

Differences between SQL and HQL: SQL is based on a relational database model whereas HQL is a combination of object-oriented programming with relational database concepts. SQL manipulates data stored in tables and modifies its rows and columns. HQL is concerned about objects and its properties.

How do you use group by clause in HQL?

Hibernate HQL Group By Example The keyword is group by. String hql = “select bk. writer, max(bk. price) from Book as bk group by bk.

How do I query a map in SQL?

Map the fields

  1. Drag each field that you want to map and drop it in the output table.
  2. Click Save.
  3. Select the SQL Server.
  4. Click Test Connection to make sure that you can connect to the server.
  5. Select the database that will store the downloaded data.
  6. Enter a name for the table.
  7. Click OK.

What is difference between criteria and HQL?

HQL is suitable for executing Static Queries, where as Criteria is suitable for executing Dynamic Queries. HQL is to perform both select and non-select operations on the data, Criteria is only for selecting the data, we cannot perform non-select operations using criteria.

How to fetch results of each row in a HQL map?

Use the select new mapsyntax in HQL to fetch the results of each row in a Map. Take a look at the following question, that addresses the issue: How to fetch hibernate query result as associative array of list or hashmap.

What is a HQL query language?

HQL is an object-oriented query language, similar to SQL, but instead of operating on tables and columns, HQL works with persistent objects and their properties.

How do I get a unique result from a HQL query?

HQL – Get a Unique Result. HQL’s Query interface provides a uniqueResult() method for obtaining just one object from an HQL query. Although your query may yield only one object, you may also use the uniqueResult() method with other result sets if you limit the results to just the first result.

What is an example of a HQL update query?

Example of HQL update query 1 Transaction tx=session.beginTransaction (); 2 Query q=session.createQuery (“update User set name=:n where id=:i”); 3 q.setParameter (“n”,”Udit Kumar”); 4 q.setParameter (“i”,111); 5 int status=q.executeUpdate (); 6 System.out.println (status); 7 tx.commit ();

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