[jira] [Updated] (CAY-2468) Support subqueries in Expression API

["Nikita Timofeev (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CAY-2468?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Nikita Timofeev updated CAY-2468:
---------------------------------
    Description: 
Currently there is no way to use subqueries in {{SelectQuery}} or {{ObjectSelect}}.
 So we need a way to do so in {{Expression}} API.

Simple version can be implemented like this:
{code:java}
ObjectSelect<Painting> subquery = ObjectSelect.query(...);
long count = ObjectSelect.query(Artist.class)
        .where(ExpressionFactory.exists(subquery))
        .selectCount(context);
{code}
Also we need a way to use expressions from top level query in a subquery. Maybe it can be new expression (like {{Artist.ARTIST_NAME.enclosing()}})

In a first iteration this should support {{EXISTS}} and {{IN}} subqueries.

  was:
Currently there is no way to use subqueries in {{SelectQuery}} or {{ObjectSelect}}.
So we need a way to do so, natural way of doing so is to support it in {{Expression}} API.

Simple version can be implemented like this: {code}
ObjectSelect<Painting> subquery = ObjectSelect.query(...);
long count = ObjectSelect.query(Artist.class)
        .where(ExpressionFactory.exists(subquery))
        .selectCount(context);
{code}

Also we need a way to use expressions from top level query in a subquery. Maybe it can be new expression (like {{Artist.ARTIST_NAME.enclosing()}})

In a first iteration this should support {{EXISTS}} and {{IN}} subqueries.


> Support subqueries in Expression API
> ------------------------------------
>
>                 Key: CAY-2468
>                 URL: https://issues.apache.org/jira/browse/CAY-2468
>             Project: Cayenne
>          Issue Type: Task
>          Components: Core Library, Database integration
>            Reporter: Nikita Timofeev
>            Assignee: Nikita Timofeev
>            Priority: Major
>             Fix For: 4.2.M1
>
>
> Currently there is no way to use subqueries in {{SelectQuery}} or {{ObjectSelect}}.
>  So we need a way to do so in {{Expression}} API.
> Simple version can be implemented like this:
> {code:java}
> ObjectSelect<Painting> subquery = ObjectSelect.query(...);
> long count = ObjectSelect.query(Artist.class)
>         .where(ExpressionFactory.exists(subquery))
>         .selectCount(context);
> {code}
> Also we need a way to use expressions from top level query in a subquery. Maybe it can be new expression (like {{Artist.ARTIST_NAME.enclosing()}})
> In a first iteration this should support {{EXISTS}} and {{IN}} subqueries.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)