ERD

erDiagram
  codeable_concept {
    emis_code_id VARCHAR PK
    snomed_concept_id VARCHAR FK
    snomed_description_id VARCHAR FK
  }

  snomed_concept {
    snomed_concept_id VARCHAR PK
  }

  snomed_description {
    snomed_description_id VARCHAR PK
  }

  codeable_concept }|--|{ snomed_concept : "maps_to_concept"
  codeable_concept }|--|{ snomed_description : "has_description"