borland Packages Class Hierarchy dx.dataset Package
AggDescriptor class
java.lang.Object
+----com.borland.dx.dataset.AggDescriptor
About the AggDescriptor class
Constructors Properties Methods
Implements Serializable
The AggDescriptor class collects the properties associated with an aggregation calculation. It is associated with a Column by the Column component's agg property.
Set the agg property of a Column component
to an instance of this class to define the type of aggregation to perform: count, sum,
minimum value or
maximum value. You specify a single column for the aggregation operation. You can optionally include a set of Column names to base the grouping logic of the aggregation (subtotals) or, if left unspecified, the calculation is maintained across an entire DataSet.
The update order of calc, lookup and aggregate columns is as follows:
- All lookup values are initialized in the row that is passed
to the CalcFields event handler. Calculations on aggregates must be performed in the
calcAggAdd() and calcAggDelete() event handlers.
Note: DataSet.addRow() and DataSet.updateRow() methods will be
modifed with the appropriate lookup values for any lookup columns they
may contain before the calcFields event is called.
- The calcAggAdd and calcAggDelete event handlers are both called after
the non-calculated aggregates have been updated for add or delete
operations. An update operation is performed as a delete and then followed by an
add operation.
AggDescriptor constructors
AggDescriptor properties
*Read-only properties **Write-only properties
Properties implemented in this class
Properties implemented in java.lang.Object
AggDescriptor methods
Methods implemented in java.lang.Object
- clone()
- equals(java.lang.Object)
- finalize()
- hashCode()
- notify()
- notifyAll()
- toString()
- wait()
- wait(long)
- wait(long, int)
AggDescriptor constructors
AggDescriptor(java.lang.String[], java.lang.String, com.borland.dx.dataset.AggOperator)
public AggDescriptor(String[]groupColumnNames, String aggColumnName, AggOperator aggOperator)
Constructs an AggDescriptor object with the specified parameters.
Parameters:
- groupColumnNames
- An array of Column names that define the groups of rows to aggregate on.
- aggColumnName
- The name of the Column to perform the aggregation on.
- aggOperator
- The aggregation operation to perform. See the aggOperator property for valid values.
AggDescriptor properties
aggColumnName
public String getAggColumnName()
Read-only property that returns the Column (by name) to perform the aggregation on.
aggOperator
public AggOperator getAggOperator()
Read-only property that specifies the aggregation operation to perform. Valid values are:
groupColumnNames
public String[]getGroupColumnNames()
Read-only property that returns the array of Column names that define the groups of rows to aggregate on.