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newdevs:db:fm [2024/06/12 10:21] – [reporter:datatype] smayonewdevs:db:fm [2025/07/29 11:26] (current) – [reltype] smayo
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   * [[evergreen-user:reporting_data_dictionary|Reporting data dictionary]]   * [[evergreen-user:reporting_data_dictionary|Reporting data dictionary]]
  
 +While it was written for the old desktop client, [[xul:birds_eye_view|this page is a good starting place to learn about the Fieldmapper and API calls]]:
  
-===== Things to Add to This Page: ===== +{{METATOC >:xul:birds_eye_view}}
-  * Information about the main fieldmapper classes +
-  * Example of how to navigate the fieldmapper +
-  * Relationship of the fieldmapper to reports  +
-  * Relationship of the fieldmapper to the PostgreSQL database schemas+
  
  
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 === oils_obj:fieldmapper === === oils_obj:fieldmapper ===
 +
 +=== oils_persist:cardinality ===
 +
 +This is an estimate of how many records are expected in this class.  This is used by the UI in some cases to determine whether or not it's reasonable to pre-fetch all the records of this class.  There are three possible values:
 +
 +  * low (less than 100 records)
 +  * high (100-1000 records)
 +  * unbounded (more than 1000 records)
  
 === oils_persist:tablename === === oils_persist:tablename ===
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 === reporter:label === === reporter:label ===
 This will be the name of your view in list of available report sources in the reporter, so it should be in readable language. This will be the name of your view in list of available report sources in the reporter, so it should be in readable language.
 +
  
 ==== fields ==== ==== fields ====
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 === reltype === === reltype ===
-These distinctions are to indicate key directionality. They are not to indicate nullability. 
  
-  * has_a  +There are 3 reltypes: 
-  * has_many +  * has_a -- the field physically exists as a column (as in, does not have the @oils_persist:virtual="true" attribute) on the SQL relation being described, and points to a unique key column (usually the primary key) of another SQL relation represented by another IDL class. 
-  * might_have+ 
 +  * has_many -- the field is does NOT physically exist on the described SQL relation, but instead exists as a class property that will be filled with a LIST of zero or more objects built from rows on another SQL relation, described by the <link>'s @class attribute, which have a field that contains the local SQL relation's (effective) primary key. 
 + 
 +  * might_have -- the field does NOT physically exist on the described SQL relation, and there is exactly one row on another SQL relation described by the <link>'s @class attribute that contains the local SQL relation's primary key. 
 + 
 +In other words, "might_have" is EXACTLY THE SAME as "has_many", but is guaranteed to always hold exactly one object, or NULL, rather than always hold a LIST of zero or more objects. 
 + 
 + 
 +Here's how to decide which reltype attribute to use: 
 + 
 +  * If the field is not virtual, but backed by a real column: ALWAYS use "has_a" 
 + 
 +  * If the field is virtual, but there's only ever going to be, at most, one row on the other end of the join: ALWAYS use "might_have" 
 + 
 +  * If the field is virtual, and there can be any number of rows on the other end of the join: ALWAYS use "has_many"
  
 === key === === key ===
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 === permacrud xmlns === === permacrud xmlns ===
 <code><permacrud xmlns="http://open-ils.org/spec/opensrf/IDL/permacrud/v1"></code> <code><permacrud xmlns="http://open-ils.org/spec/opensrf/IDL/permacrud/v1"></code>
-This should be the opening tag for your peramcrud area.+This should be the opening tag for your permacrud area.
  
 === actions === === actions ===
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 If using the create/update/delete actions, the class must also be mapped to an **[[newdevs:db:fm#oils_persist:tablename|oils_persist:tablename]].** If using the create/update/delete actions, the class must also be mapped to an **[[newdevs:db:fm#oils_persist:tablename|oils_persist:tablename]].**
 +
 +If you specify a permission, you must also include a ''global_required'' or ''context_field'' attribute or a ''context'' element.  Otherwise, you will get the error message "Invalid object or insufficient permissions".
  
 == context_field ==  == context_field == 
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 == owning_user == == owning_user ==
  
 +
 +===== Things to Add to This Page: =====
 +  * Information about the main fieldmapper classes
 +  * Example of how to navigate the fieldmapper
 +  * Relationship of the fieldmapper to reports 
 +  * Relationship of the fieldmapper to the PostgreSQL database schemas
newdevs/db/fm.1718202075.txt.gz · Last modified: 2024/06/12 10:21 by smayo
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