How to Fetch data from custom object to Custom Child object

Summary:

We have 3 custom Object called- Connection , Legal and Legal Child object

when ever we create new records in connection and Check box field (ShowOnQualityPageLicensed_c - Y )

Then new record /Data should create in Legal child object.

Currently we created DCL fields in ALL object to create relationship.

Content (required):

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):

Below is my code

if(ShowOnQualityPageLicensed_c=='Y')

{

if(Legal_Obj_c?.FileNumber_c=='17-1505')

{

 def LegalConnectionVO = Legal_Obj_c?.LegalconnectionCollection_c

 def vr = LegalConnectionVO.createRow();