Tailoring ESQL code for different node types

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 local environment 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.

  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 local environment tree.
• Propagate the input message to the next node in the message flow.

DatabaseInput node

You can configure the DatabaseInput node to do any of the following operations:

• Respond to updates that are made to the data in a database.
• Create one or more output messages, with none, some, or of all the content retrieved from a database, and propagate these new messages 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 local environment 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.