TRVReportRecordCountMode

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TRVReportRecordCountMode

Unit RVReportDBDataProvider;

Syntax

type
  TRVReportRecordCountMode =

    (rvrrcmDoNotUse, 

     rvrrcmUseIfAvailable, 

     rvrrcmUseAlways);

Value

Meaning

rvrrcmDoNotUse

Report Workshop avoids using DataSet.RecordCount property.

If possible, unidirectional datasets are created in this mode.

If Report Workshop needs a second pass through the results of DataSet, it closes and re-opens the dataset before moving to the first record.

Pros:

queries may be executed faster;

Contras:

Report Workshop still requires record count for some operations (if RowGenerationRule.CopyColCount > 1, or for cross-tab reports); in this case, one more query execution is added to calculate the record count;

some operations are performed less efficiently; for example, when applying queries to table rows, rows are added one by one instead of adding all rows at once;

OnDataQueryProgress is called without calculating Percent parameter

rvrrcmUseIfAvailable

Report Workshop uses DataSet.RecordCount property. It assumes that the dataset correctly processes First, Next, and Last commands.

This value cannot be used for unidirectional datasets that cannot move back to the first record.

rvrrcmUseAlways

When opening a dataset for the first time, one more query execution is performed to calculate record count. After that, the dataset is closed and re-opened.