IsConstantColumn

Declaration:	TDataTable.IsConstantColumn (ColIx: longint; var ConstVal: double): boolean;
The function IsConstantColumn returns TRUE if all values in the column ColIx are the same. The found constant value is returned in the variable parameter ConstVal (please note that ConstVal is undefined if the function returns a FALSE value.

Hint:

The comparison of the values is based on the comparison of floating point numbers, thus rounding effects have to be taken into consideration.