The Union tool appends multiple data streams into one unified stream. The tool accepts multiple inputs based on either field name or record position, creating a stacked output table. The user then has complete control to how these fields stack or match up.
Configure the tool
- Choose the preferred configuration mode. The default settings is Auto Config by Name.
- Auto Config by Name: Align fields by field name.
- Auto Config by Position: Align fields by their field order in the stream.
- Manually Configure Fields: Allows the user to manually align the inputs. When this method is chosen, the fields in each input are displayed (indicated by row #1, #2, etc.). See step 3 for instructions on this configuration.
Configuration at runtime
When the mode is set to Manually Configure Fields, Designer assumes the configuration will not change at runtime. Therefore, if anything is missing, an error will be thrown. Be careful to keep this configuration mode out of Analytic App/Macro actions.
- When either Auto Config mode is selected, the user must select how to handle nonconforming data fields.
Error Handling choices include:
- Error - Stop Processing Records: Will throw an error in the Results window, and end the schema.
- Warning - Continue Processing Records: Throw a warning in the Results window, but still run the schema.
- Ignore - Continue Processing Records: Ignore nonconforming data fields and run the schema.
Field Output handling choices include:
- Output All Fields: All fields are included. Null values populate empty fields.
- Output Common Subset of Fields: Only the fields that each input have in common are outputted.
- Click the Reset button to reset the field position By Position or By Name.
- Click inside a field and then click the arrows to manually relocate the field position.
- Select Non Blocking - Metainfo Will Not Change to allow data rows to be passed immediately downstream without waiting for all inputs to send data. This mode can only be used if the upstream metainfo will not change between configuration time and runtime.
Change in default behavior
This option is checked by default for workflows developed prior to Alteryx 10.1. This was the default behavior for earlier versions.