ERD

erDiagram
  organisation {
    emis_organisation_guid VARCHAR PK
    emis_parent_organisation_guid VARCHAR FK
    emis_ccg_organisation_guid VARCHAR FK
    emis_main_location_guid VARCHAR FK
  }

  organisation || -- o{ organisation : "parent_organisation"
  organisation || -- o{ organisation : "ccg_organisation"

  location {
    emis_location_guid VARCHAR PK
  }

  organisation }|--|{ location : "has_main_location"