Differences

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--- newdevs:db:fm [2023/05/22 10:26] – [links] tlittle
+++ newdevs:db:fm [2024/02/22 11:25] (current) – [oils_persist:virtual] tmccanna
@@ Line 2: / Line 2: @@
 ====== The Fieldmapper ======
-The fieldmapper (fm_IDL.xml) maps the fields! It defines objects’ fields, linked fields from other objects, and permissions needed to access various things. Most of the Evergreen code (including the reports engine) accesses the database content via the fieldmapper rather than accessing the database directly.
+The fieldmapper (''fm_IDL.xml'') maps the fields! It defines objects’ fields, linked fields from other objects, and permissions needed to access various things. Most of the Evergreen code (including the reports engine) accesses the database content via the fieldmapper rather than accessing the database directly.
   * [[https://git.evergreen-ils.org/?p=Evergreen.git;a=blob;f=Open-ILS/examples/fm_IDL.xml;h=a4fb45b078c1f80ccfdcb82d9bc2a8ee40fc749a;hb=HEAD|fm_IDL.xml in Evergreen git repository]]
@@ Line 13: / Line 13: @@
   * <nowiki>https://[your domain].org/reports/fm_IDL.xml</nowiki>
+Outline of fieldmapper classes:
+  * [[evergreen-user:reporting_data_dictionary|Reporting data dictionary]]
@@ Line 23: / Line 27: @@
 ===== Parts of the Fieldmapper =====
-==== Class header ====
+==== class header ====
 === class ===
@@ Line 42: / Line 46: @@
 === oils_persist:virtual ===
+This essentially means that the class or field is not "real" in the actual database table, only in the context of the IDL. It is often used for links to other classes:
+<code><field reporter:label="Hours of Operation" name="hours_of_operation"
+ oils_persist:virtual="true" reporter:datatype="link"/></code>
+It can also be used to indicate such things as a view that is defined by SQL in the IDL rather than in the database.
 === oils_persist:readonly ===