Parent child relations

When you sync with multiple objects that have a relation, e.g. parent-child relationship, make sure to sync the parent records first. When syncing the child objects, you will need to know the id of their parent in the target.

This can be done by doing a lookup in the link table of the parent record.

Example link tables for Projects (parents) and Tasks (children):

Table link_table_projects

source_id	target_id
100	p1
105	p2
109	p3

Table link_table_tasks

source_id	target_id
1	abc456
6	def789
8	ghi432

Pseudo-code to sync child objects, linked to a parent:

GET SOURCE ROWS

FOR EACH SOURCE ROW:

		CHECK IF RECORD ALREADY IN TARGET (LOOKUP IN LINK TABLE OF CHILD) ? IF NOT:
		
			1. FIND PARENT ID IN TARGET (LOOKUP IN LINK TABLE OF PARENT)
			
			2. ADD TO TARGET

Here’s the pseudo code in a bit more detail for records of type “Task” that are linked to a parent “Project”:

source_rows = dw.fetch(table)    	                      # e.g. list of "Tasks"

for row in source_rows:

	source_id = row["task_id"]
	if source_id not in link_table_tasks:                 # Task is not in target yet
		  
		parent_source_id = row["project_id"]
		parent_target_id = find_target_id(parent_source_id) # Lookup in link_table_projects
		
		target_id = target.add(target_row)