g_ETLPipelineSteps_ReadCursor

ReadCursor

Use the Object cursor to read and batch data from the model class instances.

Properties

attributes : string

The list of attributes that the cursor passes on to the next step in the pipeline.

Simple attributes, fields of complex attributes, and aggreate values can all be specified.

Example: A list of simple attributes: '(firstName lastName)
A list with a complex attribute: '(firstName (homeAddress city))
A list defining an aggregate value: '(firstName (: totalHoldings (sum (@ holdings value))))

batchSize : string

Expression specifying the number of records to include in each batch of data.

Example: 2000 and (* 20 100) are both valid values.

caption : string

String identifier for caption display in the UI.

class : string

The class object that the cursor will read.

description : string

A description for this cursor. This text is displayed as an element note in the ETL diagram.

layout : string

This attribute captures the UI layout information for rendering the model in the editor. The values change as users moves the element in the editor.

name : string

The cursor name. This name is diplayed on the diagram.

orderBy : string

A Scheme expression that controls the sorting of the data the cursor passes.

The syntax of the expression is '(((first_sort_dimension) . #t) ((second_sort_dimension) . #t) ((nth_sort_dimension) . #t)) Use #t to sort in ascending order, and #f to specify a descending order.

Example: A cursor reads from the Person class with the following order by information: '(((@ homeAddress city) . #t) ((@ firstName) . #t))
The data is sorted first by the city name in the complex homeAddress attribute, then by the person's first name.

where : string

An expression to restrict the set of class instances that the cursor reads.

Example: The Where clause '(= (@ firstName) "Joe") restricts the cursor to reading only from those classes whose firstName attribute is "Joe".

Parents

g_ETLActivitySteps_ETLPipeline - Pipelines gather and group cursors and commands together into related units, becoming the defining blocks of your ETL activities.

Parent topic: g_ETLActivitySteps_ETLPipeline