Devart Blog

VirtualDAC

Use VirtualDataSet to access objects list via TDataSet interface

Posted by on November 18th, 2016

TVirtualDataSet is a virtual dataset that can be used as an intermediate between data stored in an application and data-aware controls used in forms. TVirtualDataSet behaves the same way as any other TDataSet descendant and, therefore, it is compatible with all data-aware controls. However, it does not store data in memory. Work with TVirtualDataSet is implemented by means of events occurring during data exchange between an application and controls. As a result, you can choose a variety of entities as a data storage source: arrays, lists, records, XML files, etc.

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How to combine data from several sources using SQL and VirtualQuery

Posted by on July 28th, 2016

The VirtualQuery component allows to perform SQL queries to sources, that are not a database, but a TDataSet or any its descendant. It also allows to connect to several data sources at a time and work with them using SQL queries as with a single data source. Thus, work in heterogeneous environment is implemented, when execution results of queries to different sources can be retrieved in a single data set.

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