Difference between revisions of "QUERY"
(→Content query) |
(→Content query) |
||
Line 26: | Line 26: | ||
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. | 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 | + | 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]]. | ||
# Once the scan is finished, wait until the scanner is closed and an empty browser shows up; | # Once the scan is finished, wait until the scanner is closed and an empty browser shows up; |
Revision as of 11:53, 24 March 2015
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
There 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.
- Once the scan is finished, wait until the scanner is closed and an empty browser shows up;
- Depending on the network connection and the UBIK® sync mode, different ways of searching will be applied;
- During the search, the list might show a searching text before any objects are found;
- If any objects are found, they will be added to the list.
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).