org.axiondb.functions

Class SubstringFunction

public class SubstringFunction extends BaseFunction implements ScalarFunction, FunctionFactory

Syntax: SUBSTRING(str, m [,n]) -- m is one(1) based index.)

Version: $Revision: 1.10 $ $Date: 2005/05/10 00:15:21 $

Author: Sudhendra Seshachala Ahimanikya Satapathy Rupesh Ramachandran

Constructor Summary
SubstringFunction()
Creates a new instance of Class
Method Summary
Objectevaluate(RowDecorator row)
Returns substring of str, beginning at character m, n characters long.
DataTypegetDataType()
booleanisValid()
ConcreteFunctionmakeNewInstance()

Constructor Detail

SubstringFunction

public SubstringFunction()
Creates a new instance of Class

Method Detail

evaluate

public Object evaluate(RowDecorator row)
Returns substring of str, beginning at character m, n characters long.

  • If m is 0, it is treated as 1. If m is positive, it counts from the beginning of str to find the first character. If m is negative, it counts backwards from the end of str.
  • If n is omitted, it returns all characters to the end of str. If n is less than 1, a null is returned.
  • Floating-point numbers passed as arguments to substr are automatically converted to integers.
  • If m greater than length of str, return null. If m+n is bigger than length of str, ignore n. if str is null, return null.
  • getDataType

    public DataType getDataType()
    StringType

    isValid

    public boolean isValid()

    makeNewInstance

    public ConcreteFunction makeNewInstance()