The Concrete Value file holds one relationship per row. Each relationship is of a particular type, and has a source concept and a value. An example of a relationship taking a concrete value is given below:

322236009 | Product containing precisely paracetamol 500 milligram/1 each conventional release oral tablet (clinical drug)|   1142135004 | Has presentation strength numerator value (attribute)|  #500 where:

• 322236009 | Product containing precisely paracetamol 500 milligram/1 each conventional release oral tablet (clinical drug)|  is the source concept;

• 732944001 | Has presentation strength numerator value (attribute)|  is the relationship type concept and;

• #500 is the value
  

Table 4.2.6-1: Concrete Value file - Detailed specification

In general, the rules and behaviour of the Concrete Value file is identical to that of the Relationship file, with the destinationId column replaced with a value column.   

Only one relationship record with the same id field will be current at any point in time. The current record will be the one with the most recent effectiveTime before or equal to the point in time under consideration.

If the active field of this record is false ('0'), then the relationship is inactive at that point in time. If the active field is true ('1'), then there is a relationship between the SNOMED CT concepts identified by sourceId and value.

The sourceId, typeId, value, relationshipGroup, characteristicTypeId and modifierId will not change between two rows with the same id.  In other words, they are immutable. Where a change is required to one of these fields, then the current row will be de-activated (by appending a row with the same id and the active field set to false) and a new row with a new id will be appended. The relationshipGroup field is used to group relationships with the same sourceId field into one or more logical sets. A relationship with a relationshipGroup field value of '0' is considered not to be grouped. All relationships with the same sourceId and non-zero relationshipGroup are considered to be logically grouped.

The relationshipGroup field will be an unsigned Integer, and will not be limited to a single digit value. There is no guarantee that they will be assigned sequentially, and the values will not be unique across concepts.

The value field is restricted to 4096 (4K) characters in length.

Related Links

• SNOMED CT Machine Readable Concept Model.
• 3.1.3. Relationships
• Appendix C. Unicode UTF-8 encoding

• Relationship