openjava.ptree
Class QueryExpression

java.lang.Object
  |
  +--openjava.ptree.ParseTreeObject
        |
        +--openjava.ptree.NonLeaf
              |
              +--openjava.ptree.SetExpression
                    |
                    +--openjava.ptree.QueryExpression

All Implemented Interfaces:

Cloneable, Expression, ParseTree, VariableInitializer

public class QueryExpression

extends SetExpression

QueryExpression is a Saffron extension to Java syntax which represents a SQL-like relational expression.

The general form is

 select ... group by ... from ... where ... order by ...
 

When used as an expression, a QueryExpression evaluates to an array, but you can also use it inside a for (variable in select ...) construct. When used in this way, it is evaluated as an iterator.

A null groupList means don't aggregate, whereas an empty groupList means group by the 0-tuple {}, which produces a single row even if there are no input rows.

Field Summary

(package private) boolean

boxed

Fields inherited from class openjava.ptree.SetExpression

Fields inherited from class openjava.ptree.NonLeaf

Fields inherited from class openjava.ptree.ParseTreeObject

debugFlag, debugLevel, LN, out, writerStack

Constructor Summary

QueryExpression(ExpressionList selectList, boolean boxed, ExpressionList groupList, Expression from, Expression where, ExpressionList sortList)

Method Summary

void	accept(ParseTreeVisitor v) Accepts a ParseTreeVisitor object as the role of a Visitor in the Visitor pattern, as the role of an Element in the Visitor pattern.
OJClass	deriveRowType(Environment env)
Expression	getFrom()
ExpressionList	getGroupList()
ExpressionList	getSelectList()
ExpressionList	getSort()
Expression	getWhere()
boolean	isBoxed()

Methods inherited from class openjava.ptree.SetExpression

flatten, flatten, getRowType, getType

Methods inherited from class openjava.ptree.NonLeaf

childrenAccept, childrenAreEqual, elementAt, equals, getComment, getContents, getLength, makeRecursiveCopy, replaceChildWith, set, set, set, set, set, set, set, set, set, setComment, setElementAt, writeCode

Methods inherited from class openjava.ptree.ParseTreeObject

clone, eq, eq, equal, flushPrintWriter, getDebugFlag, getNest, getObjectID, getParent, getPrintWriter, getTab, hashCode, lastObjectID, makeCopy, popNest, popPrintWriter, pushNest, pushPrintWriter, replace, setDebugFlag, setDebugLevel, setNest, setParent, setPrintStream, setTab, toFlattenString, toString, writeDebug, writeDebugL, writeDebugLln, writeDebugln, writeDebugLR, writeDebugR, writeDebugRln, writeTab

Methods inherited from class java.lang.Object

equals, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface openjava.ptree.ParseTree

childrenAccept, eq, equals, getObjectID, makeCopy, makeRecursiveCopy, replace, toFlattenString, toString, writeCode

Field Detail

boxed

boolean boxed

Constructor Detail

QueryExpression

public QueryExpression(ExpressionList selectList,
                       boolean boxed,
                       ExpressionList groupList,
                       Expression from,
                       Expression where,
                       ExpressionList sortList)

Method Detail

getSelectList

public ExpressionList getSelectList()

isBoxed

public boolean isBoxed()

getGroupList

public ExpressionList getGroupList()

getFrom

public Expression getFrom()

getWhere

public Expression getWhere()

getSort

public ExpressionList getSort()

accept

public void accept(ParseTreeVisitor v)
            throws ParseTreeException

Description copied from interface: ParseTree

Accepts a ParseTreeVisitor object as the role of a Visitor in the Visitor pattern, as the role of an Element in the Visitor pattern.

This invoke an appropriate visit() method on the accepted visitor.

Specified by:

accept in interface ParseTree

Specified by:

accept in class ParseTreeObject

Parameters:

v - a visitor

ParseTreeException

deriveRowType

public OJClass deriveRowType(Environment env)
                      throws Exception

Specified by:

deriveRowType in class SetExpression

Exception