如何通过REST API执行Apache Ignite SQL查询及跨缓存关联查询

Great questions about Apache Ignite's REST API capabilities! Let's break down your two queries clearly:

Absolutely, you can filter records based on POJO field values using Ignite's REST API—you just need to leverage its SQL query support. Here's how it works:

• First, ensure your POJOs are set up for SQL access: Annotate the fields you want to query with @QuerySqlField (add indexing if you need better performance for frequent queries). Alternatively, configure your cache with IndexedTypes to register the POJO classes and their queryable fields.
• Use the REST API's sql or sql-query endpoint (depending on your Ignite version) to execute a SELECT statement with WHERE clauses targeting your POJO fields. For example, a POST request to http://<ignite-node>:8080/sql could include a body like:

  {
    "sql": "SELECT * FROM Person WHERE age > 30 AND department = 'Engineering'"
  }
  

  This will return all Person records matching those field value filters—no need to know the keys upfront.

Yes, Ignite supports cross-cache SQL joins through the REST API, as long as the related fields across your caches are properly configured for SQL:

• Make sure the fields you want to join on are annotated with @QuerySqlField (index them too for smoother join performance) in their respective POJOs.
• Reference the cache and POJO in your SQL query using the format <cache-name>.<pojo-class-name> (if you haven't set a SQL alias for the cache). For example, if you have a Person cache and an Order cache linked by a personId field, you could run a join query like this via REST:

  {
    "sql": "SELECT p.name, o.orderNumber FROM PersonCache.Person p JOIN OrderCache.Order o ON p.id = o.personId WHERE p.city = 'Chicago'"
  }
  

  The REST API will handle executing this distributed join across the caches and return the combined results.

Just a quick note: Ensure your Ignite cluster has SQL enabled (it's on by default in most setups) and that your caches are configured to support SQL operations.

内容的提问来源于stack exchange，提问作者Tarun Patel