mergenode properties

Merge node icon The Merge node takes multiple input records and creates a single output record containing some or all of the input fields. It's useful for merging data from different sources, such as internal customer data and purchased demographic data.

Example

node = stream.create("merge", "My node")
# assume customerdata and salesdata are configured database import nodes
stream.link(customerdata, node)
stream.link(salesdata, node)
node.setPropertyValue("method", "Keys")
node.setPropertyValue("key_fields", ["id"])
node.setPropertyValue("common_keys", True)
node.setPropertyValue("join", "PartialOuter")
node.setKeyedPropertyValue("outer_join_tag", "2", True)
node.setKeyedPropertyValue("outer_join_tag", "4", True)
node.setPropertyValue("single_large_input", True)
node.setPropertyValue("single_large_input_tag", "2") 
node.setPropertyValue("use_existing_sort_keys", True)
node.setPropertyValue("existing_sort_keys", [["id", "Ascending"]])

Table 1. mergenode properties
`mergenode` properties	Data type	Property description
`method`	`Order` `Keys` `Condition` `Rankedcondition`	Specify whether records are merged in the order they are listed in the data files, if one or more key fields will be used to merge records with the same value in the key fields, if records will be merged if a specified condition is satisfied, or if each row pairing in the primary and all secondary data sets are to be merged; using the ranking expression to sort any multiple matches into order from low to high.
`condition`	string	If `method` is set to `Condition`, specifies the condition for including or discarding records.
`key_fields`	list
`common_keys`	flag
`join`	`Inner` `FullOuter` `PartialOuter` `Anti`
`outer_join_tag.n`	flag	In this property, n is the tag name as displayed in the node properties. Note that multiple tag names may be specified, as any number of datasets could contribute incomplete records.
`single_large_input`	flag	Specifies whether optimization for having one input relatively large compared to the other inputs will be used.
`single_large_input_tag`	string	Specifies the tag name as displayed in the note properties. Note that the usage of this property differs slightly from the `outer_join_tag` property (flag versus string) because only one input dataset can be specified.
`use_existing_sort_keys`	flag	Specifies whether the inputs are already sorted by one or more key fields.
`existing_sort_keys`	[['string', `'Ascending'`] \ ['string'', `'Descending'`]]	Specifies the fields that are already sorted and the direction in which they are sorted.
`primary_dataset`	string	If `method` is `Rankedcondition`, select the primary data set in the merge. This can be considered as the left side of an outer join merge.
`rename_duplicate_fields`	boolean	If `method` is `Rankedcondition`, and this is set to `Y`, if the resulting merged data set contains multiple fields with the same name from different data sources the respective tags from the data sources are added at the start of the field column headers.
`merge_condition`	string
`ranking_expression`	string
`Num_matches`	integer	The number of matches to be returned, based on the `merge_condition` and `ranking_expression`. Minimum 1, maximum 100.
`default_sort_order`	`Ascending` `Descending`	Specify whether, by default, records are sorted in ascending or descending order of the sort key values.