ESQL field references overview

An ESQL field reference is a sequence of period-separated values that identify a specific field (which might be a structure) within a message tree or a database table.

The path from the root of the information to the specific field is traced using the parent-child relationships.

A field reference is used in an ESQL statement to identify the field that is to be referenced, updated, or created within the message or database table. For example, you might use the following identifier as a message field reference:

Body.Invoice.Payment

You can use an ESQL variable of type REFERENCE to set up a dynamic pointer to contain a field reference. This might be useful in creating a fixed reference to a commonly-referenced point within a message; for example the start of a particular structure that contains repeating fields.

A field reference can also specify element types, XML namespace identifications, indexes and a type constraint; see ESQL field reference overview for further details.

The first name in a field reference is sometimes known as a Correlation name.