org.sqlproc.engine.impl

Class SqlMetaLogExpr

java.lang.Object

org.sqlproc.engine.impl.SqlMetaLogExpr

All Implemented Interfaces:

SqlMetaElement, SqlMetaLogOperand

 class SqlMetaLogExpr
extends Object
implements SqlMetaElement, SqlMetaLogOperand

A META SQL sub-element.

Schematically:

 SqlMetaLogExpr
     SqlMetaIdent
     SqlMetaConst
     SqlMetaLogOperator
     SqlMetaLogExpr for embedded ()
 

Author:

Vladimir Hudec

Field Summary

Fields

Modifier and Type	Field and Description
(package private) List<SqlMetaLogOperand>	elements The list of sub-elements based on ANTLR grammar.
(package private) org.slf4j.Logger	logger The internal slf4j logger.
private boolean	not The indicator, which reverses the final logical value.

Fields inherited from interface org.sqlproc.engine.impl.SqlMetaElement

AND_PREFIX, CONST_PREFIX, IDENT_PREFIX, IDENT_SEPARATOR, lCONST_PREFIX, lIDENT_PREFIX, OR_PREFIX, SET_PREFIX, VALUES_PREFIX, WHERE_PREFIX

Constructor Summary

Constructors

Constructor and Description
SqlMetaLogExpr() Creates a new instance.
SqlMetaLogExpr(boolean not) Creates a new instance of this entity.

Method Summary

Methods

Modifier and Type	Method and Description
(package private) void	addElement(SqlMetaLogOperand element) Adds a new sub-element.
(package private) boolean	isNot() Returns the indicator, which reverses the final logical value.
SqlProcessResult	process(SqlProcessContext ctx) The main contract for a dynamic ANSI SQL Query generation.
boolean	processExpression(SqlProcessContext ctx) The main contract to evaluate a logical value of META SQL sub-elements.
(package private) void	setNot(boolean not) Sets the indicator, which reverses the final logical value.

Methods inherited from class java.lang.Object

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

Field Detail

logger

final org.slf4j.Logger logger

The internal slf4j logger.

not

private boolean not

The indicator, which reverses the final logical value.

elements

List<SqlMetaLogOperand> elements

The list of sub-elements based on ANTLR grammar. The evaluation of these sub-elements is little bit different compared to the evaluation of sub-elements in other SqlMetaXXX components. Every sub-element must bu true, not not-empty.

Constructor Detail

SqlMetaLogExpr

SqlMetaLogExpr()

Creates a new instance. It's used from inside ANTLR parser.

SqlMetaLogExpr

SqlMetaLogExpr(boolean not)

Creates a new instance of this entity. Used from inside ANTLR parser.

Parameters:

not - the indicator, which reverses the final logical value

Method Detail

addElement

void addElement(SqlMetaLogOperand element)

Adds a new sub-element. It's used from inside ANTLR parser.

Parameters:

element - new sub-element, based on ANTLR grammar

isNot

boolean isNot()

Returns the indicator, which reverses the final logical value.

Returns:

the indicator value

setNot

void setNot(boolean not)

Sets the indicator, which reverses the final logical value.

Parameters:

not - a new value of the indicator

processExpression

public boolean processExpression(SqlProcessContext ctx)

The main contract to evaluate a logical value of META SQL sub-elements.

Specified by:

processExpression in interface SqlMetaLogOperand

Parameters:

ctx - the context for a dynamic ANSI SQL Query generation

Returns:

a logical value

process

public SqlProcessResult process(SqlProcessContext ctx)

The main contract for a dynamic ANSI SQL Query generation. Also known as a META SQL processing. The composite pattern main contract. All ANTLR grammar based elements must implement this contract.

Specified by:

process in interface SqlMetaElement

Parameters:

ctx - the crate for all input parameters and the context of processing