org.axiondb.functions
Class SubstringFunction
java.lang.Object
org.axiondb.BaseSelectable
org.axiondb.functions.BaseFunction
org.axiondb.functions.SubstringFunction
- All Implemented Interfaces:
- Serializable, Function, FunctionFactory, ConcreteFunction, ScalarFunction, Selectable
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 $
- See Also:
- Serialized Form
SubstringFunction
public SubstringFunction()
- Creates a new instance of Class
makeNewInstance
public ConcreteFunction makeNewInstance()
- Specified by:
makeNewInstance
in interface FunctionFactory
getDataType
public DataType getDataType()
StringType
- Specified by:
getDataType
in interface Selectable
- Specified by:
getDataType
in class BaseFunction
evaluate
public Object evaluate(RowDecorator row)
throws AxionException
- 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.
- Specified by:
evaluate
in interface ScalarFunction
- Specified by:
evaluate
in interface Selectable
- Throws:
AxionException
isValid
public boolean isValid()
- Specified by:
isValid
in interface ConcreteFunction
- Specified by:
isValid
in class BaseFunction