Package org.apache.drill.exec.expr.fn.impl

Class DateTypeFunctions.IsDate

java.lang.Object

org.apache.drill.exec.expr.fn.impl.DateTypeFunctions.IsDate

All Implemented Interfaces:

DrillFunc, DrillSimpleFunc

Enclosing class:

DateTypeFunctions

public static class DateTypeFunctions.IsDate
extends Object
implements DrillSimpleFunc

Function to check if a varchar value can be cast to a date. At the time of writing this function, several other databases were checked for behavior compatibility. There was not a consensus between oracle and Sql server about the expected behavior of this function, and Postgres lacks it completely. Sql Server appears to have both a DATEFORMAT and language locale setting that can change the values accepted by this function. Oracle appears to support several formats, some of which are not mentioned in the Sql Server docs. With the lack of standardization, we decided to implement this function so that it would only consider date strings that would be accepted by the cast function as valid.

Constructor Summary

Constructors

Constructor	Description
IsDate()

Method Summary

Modifier and Type	Method	Description
void	eval()
void	setup()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

IsDate

public IsDate()

Method Details

setup

public void setup()

Specified by:

setup in interface DrillSimpleFunc

eval

public void eval()

Specified by:

eval in interface DrillSimpleFunc