Datasets in QPR UI

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Revision as of 14:52, 28 November 2017 by Ollvihe (talk | contribs)
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Datasets are used to fetch data from external datasource and systems, and present that data in QPR UI views. Dataset has a tabular form, it contains zero to many rows, and one to many named and ordered columns. Dataset columns are ordered, which means that the columns are in a certain order. Dataset columns can be referred either using column name or column index (starting from one from the left). Dataset cells may contain the following data types: string, integer, decimal, boolean and date. Date values are integer values representing the number of milliseconds since 1 January 1970 00:00:00 UTC with leap seconds ignored (i.e. the "Unix Epoch"). Usually all cells for a certain column contain same type of data.

Datasets can be defined all UI element levels, such as views, panels, repeaters and presentation objects. For that, the Datasets tab is available in all levels. The defined dataset is available for presentation objects in the same level or any level below it in the UI element's hierarchy.

When a dataset is defined, an identifier for the dataset needs to be defined. Dataset identifier is used to refer to the dataset when the dataset is used by presentation objects. Dataset identifiers must be unique in a single UI element level, which means that you cannot specify two datasets having the same identifier in the same level. Datasets in different levels may have same identifiers and when referring to a dataset, the reference is made always to the nearest dataset when going up in the UI element hierarchy, i.e. the dataset in a lower level overrides a same identifier dataset in the upper level.

When defining a dataset, you need to specify from which datasource the data is queried. In addition, you need to define a query and parameters (depends on the datasource) which determine which kind of data is fetched from the datasource. For example, in QPR Suite you can query different type of QPR Metrics, QPR ProcessDesigner or QPR EnterpriseArchitect objects and in QPR ProcessAnalyzer you can request different analyses. In the dataset query and parameters you can use Variable and Expression tags which enables more dynamic behavior when quering data. When the referenced context variables change, the queries that use the variables are rerun to the datasource and fetched datasets are updated. As a result, presentation objects using those datasets are updated as well.

Following datasources are available: