Changes between Initial Version and Version 1 of UserGuidelines/Import/UpdateDetection

Timestamp:

09/13/12 07:54:50 (13 years ago)

Author:

Dominic König

Comment:

--

UserGuidelines/Import/UpdateDetection

@@ +1 @@
+= Update Detection during Imports =
+
+Data imports can do both - create new records in the database and update existing ones.
+
+If Sahana Eden can identify an import item with an existing record, this record will be updated rather than a new record being created.
+
+In order to identify the import item, Eden uses a cascade of rules:
+
+  1. Identification by UUID
+  2. Identification by other unique keys
+  3. Identification by table-specific rules
+
+== Identification by UUID ==
+
+Every record in the Sahana Eden database has a UUID field (universally unique identifier), see [wiki:UUID]. If an import item contains a UUID and it matches an existing database record, this record will be updated rather than creating a new record.
+
+== Identification by Other Unique Keys ==
+
+Some database tables use additional unique keys, e.g. the "name" field in organisations. These keys can be used instead of UUIDs to indicate updates - however: if there is also a UUID present in the import item, then only the UUID will be used to identify the record to update.
+
+== Table-Specific Identification Rules ==
+
+For many database tables, Sahana Eden has additional table-specific rules to identify records in cases where the import item does not contain a UUID and no match can be found by unique keys.
+
+=== Person Records ===
+
+   - ''tbw''