Tailoring ESQL code for different node types

When you code ESQL to configure Compute, Database, and Filter node behavior, be aware of the limitations of each type of node:

Compute node
You can configure the Compute node to do any of the following operations:
  • Update data in a database.
  • Insert data into a database.
  • Delete data from a database.
  • Update the Environment tree.
  • Update the LocalEnvironment tree.
  • Create one or more output messages, with none, some, or all the content of the input message, and propagate these new messages to the next node in the message flow.

    If you want to propagate the input LocalEnvironment to the output LocalEnvironment, remember to set the Compute node property Compute mode to an appropriate value. The Environment is always propagated in the output message.

Database node
You can configure the Database node to do any of the following operations:
  • Update data in a database.
  • Insert data into a database.
  • Delete data from a database.
  • Update the Environment tree.
  • Update the LocalEnvironment tree.
  • Propagate the input message to the next node in the message flow.
Filter node
You can configure the Filter node to do any of the following operations:
  • Update data in a database.
  • Insert data into a database.
  • Delete data from a database.
  • Update the Environment tree.
  • Update the LocalEnvironment tree.
  • Propagate the input message to the next node in the message flow (the terminal through which the message is propagated depends on the result of the filter expression).

View the remaining tasks in this section to find the details of how you can perform these operations.

Related concepts
Message flows overview
ESQL overview
Related tasks
Designing a message flow
Defining message flow content
Related reference
Compute node
Database node
Filter node
ESQL reference