The Query Spatial Data stage allows you to query spatial data using MI SQL functions (SELECT, FROM with multiple tables for joins, WHERE, GROUP BY, ORDER BY, LIMIT, and OFFSET). You can use fields as parameters in a spatial data query. For example, if you read the field "AddressLine1" from a flat file, you can create a query to select from a spatial data source with the value for AddressLine1 as a parameter value. The named tables you are querying from must be present in the repository before using them with MI SQL in this stage. This stage also accepts geometries that are generated by stages in the Enterprise Routing Module, such as a LineString or Polygon.
The difference between the Read Spatial Data and Query Spatial Data stages is that the Read Spatial Data stage is a source stage that has no upstream stage connected. The Query Spatial Data stage, however, requires an upstream stage that can pass in parameters for the query. Auto-complete displays functions and operators to facilitate query construction.
To use this stage, enter the MI SQL query statement in the text area and click Verify. You can also specify a number of runtime instances (see the Dataflow Designer's Guide for detailed information on runtime performance options).