MarkLogic java API join 2 documents

Question

Is there a way to join 2 documents within a marklogic database utilizing MarkLogic's Java API?

For instance let's say there's the following 2 documents:

doc1.xml:

<a>    
    <id>123</id>
    <doc2ID>111</doc2ID>
    <first_name>John</first_name>
</a>

doc2.xml:

<b>
    <id>111</id>
    <doc1ID>123</doc1ID>
    <last_name>Smith</last_name>
    <age>25</age>
</b>

Can i make the following query in MarkLogic: retrieve all records where first name = John, last_name = Smith and age > 20 ? In sql you would do something like this: Select a.first_name, b.last_name from doc1 a JOIN doc2 b ON (a.doc2ID = b.id) WHERE a.first_name = 'John' and b.last_name = 'Smith' and b.age > 24

Answer 1

If you just want to use one document as a filter for another, you can send Query Options with a custom constraint that implements the subquery.

If you actually want to join documents, you would have to create a resource service extension that implements the join at the cts:search() level.

Stepping back, however, you should consider denormalizing your documents so you don't need to join as much as you would in a relational database. The documents you provide above are, in essence, table rows, which does not take advantage of the power and flexibility of a document database. Using relational models and relational queries is not the best approach in a document database.