TCustomRVReportGenerator.OnCreateQueryProcessor

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TCustomRVReportGenerator.OnCreateQueryProcessor

Allows providing a custom query processor for the specific DataQuery.

type

  TRVCreateQueryProcessorEvent = procedure (

    Sender: TCustomRVReportGenerator;

    const DataQuery: TRVUnicodeString;

    var QueryProcessor: TRVReportQueryProcessorof object;

 

property OnCreateQueryProcessor: TRVCreateQueryProcessorEvent;

This is an optional event. Normally, query processors are created by a linked data provider component. However, you can use this event:

if you want to use a non-standard query processor;

if you want to use different query processors for different data queries.

 

Input parameters

DataQuery – a data query string (such as SQL SELECT statement). This string is already processed: data fields and variables in it are replaced to their values.

Output parameters

QueryProcessor – a query processor to process DataQuery. If you return nil, a default processing will be created (a query processor will be requested from a linked data provider component). QueryProcessor will be owned by the report generator and will be freed when it finishes processing DataQuery, so do not free QueryProcessor yourself.

To create QueryProcessor, you can use CreateQueryProcessor method of a data provider component.

See also:

Definitions of Report Workshop terms