Associations between Component Files

The logical model of between the components in the release files is shown in  . The component class represents columns present in all three component files. The individual classes (description, concept and relationship) only show the additional columns present in those files. The colored lines between descriptions and concepts and between relationships and concepts represent the link between the foreign keys (shown in bold) and the id of the concept. These provide the functional connections between components described in this document. The grey lines indicate additional links between columns that are populated with concept identifiers that provide enumerated values.

Logical Relationships Between Component Files

A More Complete View of Release File Associations

 provides an extended view of the associations between release files following changes complete in July 2019 release of SNOMED CT

The associations shown on the page are the results of changes that occured between July 2018 and July 2019. For documentation file associations before these changes please refer to Associations Between Release Files Prior to July 2018.

. These changes enable SNOMED CT to use enhanced   features and resulted in a significant change to the way in which the   of   are represented. However the changes but did not significantly affect the structure and associations between the main component files shown in  


Associations between SNOMED CT Release Files

Detailed Notes of Release File Associations

Each is represented by a row in the  and the concept is identified by the id column in that row. There can be more than one row with the same id but with different effectiveTime values, in which case each of these rows represents a version of that same concept. Thus each row represents a version of a clinical  

Each has two or more associated with it:

Each is represented by a row in the   and is identified by the id column in that row. There can be more than one row with the same id but with different effectiveTime values, in which case each of these rows represents a version of that same description. Thus each row represents a version of a description. Each description applies to one concept to which it is linked by the conceptId. All versions of a description must relate to exactly the same identified concept (i.e. the conceptId must not change between versions).

Each from a source to a destination is represented by a row in the  . There can be more than one row with the same id but with different effectiveTime values, in which case each of these rows represents a version of that same relationship. Thus each row represents a version of a relationship. The source, destination and type each relationship are identified respectively by the sourceId, destinationId and typeId columns. All versions of a relationship must have the same sourceId, destinationId and typeId.  The typeId refers to  that is also held within the . The only concepts that can be used as the relationship typeId are or concepts that are subtypes of .

The most basic form of is the  relationship. This relationship states that one is a subtype of another . Each subtype concept is connected to its parent subtype(s) by relationships with the typeId and this form the main SNOMED CT  In this a may have more than one parent . The root of the is  , which has a set of top level each forming its own with typeid values that are subtypes of  are referred to as attribute relationship and contribute to the formal definition of the source concept.