Package org.datanucleus.store.query.compiler

Class 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.

    • Constructor Detail

      • JDOQLParser

        public JDOQLParser()
        Constructor for a JDOQL Parser.

    • Method Detail

      • 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