How to build custom relationship 1:M?

You need to create such relationship by hand.

Hi Honrao,

You can create One to Many relationship between two modules through Studio. Please go through below links to know more about how to create and types of relationships in SugarCRM.

https://support.sugarcrm.com/Knowledge_Base/Studio_and_Module_Builder/Creating_a_Relationship/ 

https://support.sugarcrm.com/Knowledge_Base/Studio_and_Module_Builder/Introduction_to_Relationships_and_Relate_Fields/#R… 

hi André Lopes
Your reply has aroused my curiosity :-)