SQL Reader Component

The SQL Reader component is designed to execute a query against a database and pass along the results.  If a SignalData object is sent to the execute channel, this component will execute the query, return the result set, then cease processing.  If another SignalData object is sent to the execute channel, the query will be executed again.  Each row will be output as a separate entity on the default channel.

Data Governance

The SQL Reader component will register every data item it returns with the Data Governance System.  If the reader was triggered by a Signal Data, the returned items are recorded as being derived from the Signal Data.

Input Channels

execute — Receives a SignalData object that instructs the component to re-execute its query.  If the query is already executing, the message is ignored and logged.

Output Channels

default — Outputs each row returned by the query one-at-a-time as a DatabaseRowData.  When the last record is returned, the isLast flag of the DatabaseRowData object will be set.

noResults— Outputs a signal if the query executes and no results are returned.

error — Outputs an ErrorOutput object when there is an error executing the query.

Parameters

resource — (SQL Database Resource) The resource defining the service to which this component should connect

query — (String) The SQL query to execute against the database.

rowsToReturnPerCall — (int: default 10) The number of rows to return per call to the database.