[jira] [Commented] (GROOVY-8258) Create a LINQ-like DSL

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[jira] [Commented] (GROOVY-8258) Create a LINQ-like DSL

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    [ https://issues.apache.org/jira/browse/GROOVY-8258?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16089601#comment-16089601 ]

Daniel Sun commented on GROOVY-8258:
------------------------------------

Time is a problem, but we can push the progress step by step. I think we can create a new sub-project linq-dsl at first ;)

> Create a LINQ-like DSL
> ----------------------
>
>                 Key: GROOVY-8258
>                 URL: https://issues.apache.org/jira/browse/GROOVY-8258
>             Project: Groovy
>          Issue Type: Improvement
>            Reporter: Daniel Sun
>
> *Pojos:*
> {code:java}
> class Category {
>    String name
>    List<Article> articles
> }
> class Article {
>   String name
>   Integer voteCount
>   String categoryName
> }
> {code}
> *Example1:*
> {code:java}
> linq { // return an Iterator<Map<String, Object>>
>     from c of categories
>     join a of articles on a.categoryName == c.name // join
>     where c.name == 'Groovy'
>     orderBy a.voteCount desc // order by
>     limit 100 offset 50 // pagination
>     select { // create a map, its keys: articleName, voteNum, categoryName
>         articleName = a.name
>         a.voteCount
>         categoryName = c.name
>     }
> }
> {code}
> *Example2:*
> {code:java}
> linq { // return an Iterator<Map<String, Object>>
>     from c of categories
>     join a of {
>         from tempA of articles
>         where tempA.voteCount > 10
>         select tempA
>     } on a.categoryName == c.name // join
>     where c.name == 'Groovy'
>     orderBy a.voteCount desc // order by
>     limit 100 offset 50 // pagination
>     select { // create a map, its keys: articleName, voteNum, categoryName
>         articleName = a.name
>         a.voteCount
>         categoryName = c.name
>     }
> }
> {code}
> *Example3:*
> {code:java}
> linq { // return an Iterator<Article>
>     from c of categories
>     from a of c.articles  // another join
>     where c.name == 'Groovy'
>     orderBy a.voteCount desc // order by
>     select Article { // create an Article instance
>         a.name
>         a.voteCount
>         categoryName = c.name
>     }
> }
> {code}
> *TO BE CONTINUED...*



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