Extended Structured Query Language (ESQL) is a programming language defined by IBM® Integration Bus to define and manipulate data within a message flow.
- For descriptions of ESQL user tasks, see Writing ESQL.
- For reference information about ESQL, see ESQL reference.
- An overview of message flows in Message flows overview.
- An overview of message trees in The message tree, and the topics within this container, paying special attention to Logical tree structure.
ESQL is based on Structured Query Language (SQL) which is in common usage with relational databases such as IBM DB2®. ESQL extends the constructs of the SQL language to provide support for you to work with message and database content to define the behavior of nodes in a message flow.
The ESQL code that you create to customize nodes within a message flow is defined in an ESQL file, typically named <message_flow_name>.esql, which is associated with the integration project. You can use ESQL in the following built-in nodes:
You can also use ESQL to create functions and procedures that you can use in the Mapping node.
To use ESQL correctly and efficiently in your message flows, you must also understand the following concepts:
Use the ESQL debugger, which is part of the flow debugger, to debug the code that you write. The debugger steps through ESQL code statement by statement, so that you can view and check the results of every line of code that is run.