org.datanucleus.query.compiler

Class JDOQLParser

java.lang.Object

org.datanucleus.query.compiler.AbstractParser

org.datanucleus.query.compiler.JDOQLParser

All Implemented Interfaces:

Parser

public class JDOQLParser
extends AbstractParser

Implementation of a parser for JDOQL query language. Generates Node tree(s) by use of the various parseXXX() methods.

Field Summary

Fields inherited from class org.datanucleus.query.compiler.AbstractParser

lexer, stack, strict

Constructor Summary

Constructors

Constructor and Description
JDOQLParser() Constructor for a JDOQL Parser.

Method Summary

Modifier and Type	Method and Description
void	allowSingleEquals(boolean flag) Method to set whether "=" is allowed.
Node	parse(String expression)
Node[]	parseFrom(String expression)
Node[]	parseOrder(String expression)
Node[][]	parseParameters(String expression)
Node[]	parseResult(String expression) The RESULT expression in JDOQL can include aggregates, fields, as well as aliases myfield [AS] alias, myfield2" The Node tree for this would be
Node[]	parseTuple(String expression)
Node[]	parseUpdate(String expression)
Node	parseVariable(String expression)
Node[][]	parseVariables(String expression)
protected void	processAdditiveExpression()
protected boolean	processLiteral() A literal is one value of any type.
protected void	processMultiplicativeExpression()
protected void	processPrimary() Parses the primary.
protected void	processUnaryExpression()
void	setExplicitParameters(boolean flag)

Methods inherited from class org.datanucleus.query.compiler.AbstractParser

getLastDescendantNodeForNode, setStrict

Methods inherited from class java.lang.Object

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

Constructor Detail

JDOQLParser

public JDOQLParser()

Constructor for a JDOQL Parser.

Method Detail

setExplicitParameters

public void setExplicitParameters(boolean flag)

Specified by:

setExplicitParameters in interface Parser

Overrides:

setExplicitParameters in class AbstractParser

allowSingleEquals

public void allowSingleEquals(boolean flag)

Method to set whether "=" is allowed. It is valid in an UPDATE clause, but not in a WHERE clause, for example.

Parameters:

flag - Whether to allow it

parse

public Node parse(String expression)

parseVariable

public Node parseVariable(String expression)

parseFrom

public Node[] parseFrom(String expression)

parseUpdate

public Node[] parseUpdate(String expression)

parseOrder

public Node[] parseOrder(String expression)

parseResult

public Node[] parseResult(String expression)

The RESULT expression in JDOQL can include aggregates, fields, as well as aliases

• myfield [AS] alias, myfield2"

The Node tree for this would be

[
 [IDENTIFIER : myfield.
      [NAME : alias]],
 [IDENTIFIER : myfield2]
 ]

Returns:

Node tree(s) for the RESULT expression

parseTuple

public Node[] parseTuple(String expression)

parseVariables

public Node[][] parseVariables(String expression)

parseParameters

public Node[][] parseParameters(String expression)

processAdditiveExpression

protected void processAdditiveExpression()

processMultiplicativeExpression

protected void processMultiplicativeExpression()

processUnaryExpression

protected void processUnaryExpression()

processPrimary

protected void processPrimary()

Parses the primary. First look for a literal (e.g. "text"), then an identifier(e.g. variable) In the next step, call a function, if executing a function, on the literal or the identifier found.

processLiteral

protected boolean processLiteral()

A literal is one value of any type. Supported literals are of types String, Floating Point, Integer, Character, Boolean and null e.g. 'J', "String", 1, 1.8, true, false, null.

Returns:

The parsed literal