The Query Language Usage

The query language can be used to create and execute queries, and use results returned by a query.

  • Queries Construction and Query Results Usage
    To implement queries, you put query text (SQL-like statements) as arguments to an appropriate function from the CEP Query function catalog and place the query functions in one or more rule functions. You can also use bind variables in many clauses to create prepared statements.
  • Lifecycle of a Query—Use of Query Functions
    Lifecycle of a query involves creation, execution, and gathering of results. Functions can be used to create and execute queries, and to gather query results.
  • Result Set Data Usage (Snapshot Queries)
    Use the Query.Statement.execute() function to returns values in a result set.
  • Callback Rule Function Data Usage
    The data provided to the callback rule function depends on which callback function you are using.
  • The Delete Query
    The delete query is typically used to delete the temporary concepts, which are no longer required.
  • Simple Snapshot Query Example
    The snapshot query example code could be placed in a preprocessor rule function that receives an event called requestEvent. The example code includes all steps from creating to closing the query.
  • Simple Continuous Query Example
    The continous query example shows how a callback rule function is used to gather results generated by the query.
  • Example Showing Batching of Return Values (Continuous Queries)
    The example is the same as the simple continous query example, with the addition of an order by clause in the query text, to show batching behavior. Only the output and function calls differ.
  • Bind Variables in Query Text
    Query definitions can use literal values for entity attributes in query text, or they can use bind variables whose values are provided at runtime.
  • Collocated Inference Agents and Dynamic Query Agent Sessions
    Depending on the need, it can be useful to deploy an inference agent in the same processing unit (node) as the query agent. Another way to integrate query and inference functionality is to dynamically start a collocated query agent session from an inference agent.
  • Design Optimization
    You can implement few basic sstrategies for optimizing the design when working with queries.