org.apache.torque.util.functions
Class Aggregate.AgregateFunction

java.lang.Object
  org.apache.torque.util.functions.AbstractFunction
      org.apache.torque.util.functions.Aggregate.AgregateFunction

All Implemented Interfaces:

SQLFunction

Direct Known Subclasses:

Aggregate.Avg, Aggregate.Count, Aggregate.Max, Aggregate.Min, Aggregate.Sum

Enclosing class:

Aggregate

public abstract class Aggregate.AgregateFunction
extends AbstractFunction
implements SQLFunction

The base class for all the standard aggregate function classes.

Constructor Summary

protected

Aggregate.AgregateFunction() Base constructor for aggregate functions which must be created via the FunctionFactory / DB classes.

Method Summary

java.lang.String	getArgument(int index) Return a string representation of the function parameter at the specified index.
protected java.lang.String	getFunction() Get the function name to use, e.g.
boolean	isDistinct() Should the column have DISTINCT added in front of it?
void	setArguments(java.lang.Object[] args) Assumes that there are one or two arguments being specified.
void	setFunction(java.lang.String value) Set the function to use.
java.lang.String	toSQL() Generate the SQL for this function.

Methods inherited from class org.apache.torque.util.functions.AbstractFunction

addArgument, getArgumentList, getArgumentObject, getArguments, getDBName, setArgumentList, setDBName

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.torque.util.functions.SQLFunction

getArguments, getDBName, setDBName

Constructor Detail

Aggregate.AgregateFunction

protected Aggregate.AgregateFunction()

Base constructor for aggregate functions which must be created via the FunctionFactory / DB classes.

See Also:

FunctionFactory, DB

Method Detail

setArguments

public void setArguments(java.lang.Object[] args)
                  throws java.lang.IllegalArgumentException

Assumes that there are one or two arguments being specified. The first being a column identifier. (TODO: handle expressions) and the second being an optional boolean indicating if DISTINCT needs to be added.

Specified by:

setArguments in interface SQLFunction

Parameters:

args - The column to apply the function to.

Throws:

java.lang.IllegalArgumentException - If at least one argument has not been supplied or the second argument object is not Boolean.

isDistinct

public boolean isDistinct()

Should the column have DISTINCT added in front of it?

Returns:

True if DISTINCT is needed.

getFunction

protected java.lang.String getFunction()

Get the function name to use, e.g. AVG, MIN, LEAST.

Returns:

The function.

setFunction

public void setFunction(java.lang.String value)

Set the function to use.

Parameters:

value - The function to use.

toSQL

public java.lang.String toSQL()
                       throws java.lang.IllegalStateException

Generate the SQL for this function.

Specified by:

toSQL in interface SQLFunction

Specified by:

toSQL in class AbstractFunction

Returns:

The SQL String.

Throws:

java.lang.IllegalStateException

getArgument

public java.lang.String getArgument(int index)

Description copied from class: AbstractFunction

Return a string representation of the function parameter at the specified index. Should be null if parameter does not exist.

Specified by:

getArgument in interface SQLFunction

Specified by:

getArgument in class AbstractFunction

Parameters:

index - The 0 based parameter to get.

Returns:

A String representation of the parameter. Null if one does not exist.