Relationship
One to one is where Primary key of one entity is Primary key of another entity .
One to Many will be. Primary key of one table should be florigen key of another table.
Keep in mind the deletion rules .
Hi @Chetan,
About entity relationship details you can check attach document.
https://success.outsystems.com/documentation/11/developing_an_application/use_data/data_modeling/entity_relationships/
Thanks,
Sonali verma