org.apache.metamodel.query

Interface ScalarFunction

All Superinterfaces:

FunctionType

All Known Implementing Classes:

DefaultScalarFunction, ToBooleanFunction, ToDateFunction, ToNumberFunction, ToStringFunction

public interface ScalarFunction
extends FunctionType

Interface that contains scalar specific methods. Scalar functions returns only a single value, based on the input value.

Field Summary

Fields inherited from interface org.apache.metamodel.query.FunctionType

AVG, COUNT, MAX, MIN, SUM, TO_BOOLEAN, TO_DATE, TO_NUMBER, TO_STRING

Method Summary

Methods

Modifier and Type	Method and Description
Object	evaluate(Row row, SelectItem operandItem) Applies and evaluates the function on a particular row of data.

Methods inherited from interface org.apache.metamodel.query.FunctionType

getExpectedColumnType, getFunctionName

Method Detail

evaluate

Object evaluate(Row row,
              SelectItem operandItem)

Applies and evaluates the function on a particular row of data.

Parameters:

row - the row containing data

operandItem - the select item which is the argument to this function. If a function takes multiple select items, this will be the primary one.

Returns: