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Difference between revisions of "QUERY"


(Content query)
(Content query)
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==Content query ==
 
==Content query ==
Objects can be loaded on demand from the server, as storing a huge amount of data permanently on the device would need too much resources. A content query is a [[QUERY]] instance classified as [[SYSCLS_QUERY]] and can be related to other content objects. For being shown in the View hierarchy it is necessary to [[HowTo:Create_a_new_ViewItem#QueryViewItem|create a QueryViewItem]] for the query object itself. Further on, for being published to the client a [[QUERYSCOPE|Query Scopes]] has to be [[HowTo:Create_a_new_QueryScope|created]] and added to the [[ACM]].
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Objects can be loaded on demand from the server, as storing a huge amount of data permanently on the device would need too much resources. A content query is a Query instance classified as [[SYSCLS_QUERY]] and can be related to other content objects. For being shown in the View hierarchy it is necessary to [[HowTo:Create_a_new_ViewItem#QueryViewItem|create a QueryViewItem]] for the query object itself. Further on, for being published to the client a [[QUERYSCOPE|Query Scopes]] has to be [[HowTo:Create_a_new_QueryScope|created]] and added to the [[ACM]].
  
 
The result of the query depends on the network connection and the {{UBIK}} [[Sync Mode|sync mode]] and follows the same rules as [[Optical_code#Searching_for_objects|Searching for objects by Optical codes]].
 
The result of the query depends on the network connection and the {{UBIK}} [[Sync Mode|sync mode]] and follows the same rules as [[Optical_code#Searching_for_objects|Searching for objects by Optical codes]].

Revision as of 11:59, 24 March 2015

IC METACLASS.gif Query
Name QUERY
Namespace System.Query
Internal Name SystemObjects.QUERY
TypeString UBIK.Kernel.MetaClass
RuntimeType UBIK.Kernel.Query
Purpose Configure queries
Version 2+

In UBIK, queries are used for fetching a list of ContentClasses from the database. Queries use data base mechanism for perfomant data access and will deliver a list of objects of a certain Metaclass. Queries can be used in different scenarios:

  • data fetching (n records)
  • finding a single or a set of recordset(s)
  • used as definition of root nodes in a View
IC Hint square.pngThere are specific methods available for this type!

Query and QueryItems

A Query is defined for a single MetaClass, where the MetaClass is defined in the property FILTEROBJECT. Once a query is evaluated it will deliver a list of objects of type ContentClasses (instances), filtered as defined by its QueryItems. The correspondence between Queries and its items is created and stored by a relationship SYSREL QUERY. Therefore a single QueryItem can be used several times for different Queries.

Content query

Objects can be loaded on demand from the server, as storing a huge amount of data permanently on the device would need too much resources. A content query is a Query instance classified as SYSCLS QUERY and can be related to other content objects. For being shown in the View hierarchy it is necessary to create a QueryViewItem for the query object itself. Further on, for being published to the client a Query Scopes has to be created and added to the ACM.

The result of the query depends on the network connection and the UBIK® sync mode and follows the same rules as Searching for objects by Optical codes.

Scan query

Usage of DatabaseViews

It is also possible to define a Database View and use this View for the evaluation of Queries (see VirtualContentClass).

See also