Date stamps for revisions of the concept relationships
We need to be able to associate start and stop dates with the concept relationships during the editing process so as to handle versioning. We need this both in the table for concept realationships (or two tables if current and obsolete are kept separate) and in the ConceptMapper tool used for editing relationships.
Updated by xianhua liu over 15 years ago
I implemented the function and changed the database to support time-stamp of concept relationships. My solution is:
1. added 2 new fields to the mappings table to store start and end dates of a relationship.
2. added a new table 'mappinghistory' to with the same fields as the mappings table to store the history of a relaitonship.
3. changed database proxy class in ConceptMapper so that: * start date of new relationship is set to current date and end date emmpty * whenever a relatonship is changed, the old relationship is stored in the mappinghistory table with end date set to current date. The updated record will have current date as its start date * when a relationship is deleted, the relationship will physically removed from the mappings table, and the relationship is stored in the mappinghistory table with its end date set to current date.