Calculated Column can help you make statistics, summary, seek maximum, and find a minimum operation or computing to the value of a few columns in Calculate Column.
Calculated Columns exists in the JB DataSet but does not correspond to column in the database table.
Column's CalcType property can be specified as Calculated, Aggregated, and Loop Up.
Select CalcType to Calculate, you need to specify the CalcFields event in the DataSet and write processing code in the Handler of the event, for example:
Void querydataset1_calcfields (Readrow Readrow, DataRow DataRow, Boolean Boolean1) {
DataRow.SetBigDecimal ("NewColumn1", Readrow.getBigDecimal (3) .Multiply (New BigDecimal)))))
}
Select CalcType to generate the time handler to write time handler, select the AGG property, and set the relevant settings to make statistics, summary, seek maximum, and find the minimum calculation.
Calumn's ChangeD event should be used well, I used to realize the same function, every time you have to traverse DataSet, depressed!
