Package gudusoft.gsqlparser.nodes

Class TJoinExpr

Object

gudusoft.gsqlparser.nodes.TParseTreeNode

gudusoft.gsqlparser.nodes.TNodeWithAliasClause

gudusoft.gsqlparser.nodes.TJoinExpr

All Implemented Interfaces:

IRelation, Visitable, Iterator<TSourceToken>

public class TJoinExpr
extends TNodeWithAliasClause
implements IRelation

Represents a JOIN expression in SQL statements. This class replaces TJoin as of version 2.7.4.0.

A JOIN expression consists of:

• A left table/subquery (getLeftTable())
• A right table/subquery (getRightTable())
• A join type (getJointype()) - e.g. INNER, LEFT, RIGHT, FULL, CROSS
• An optional ON condition (getOnCondition())
• Optional USING columns (getUsingColumns())

For nested joins, the left and right operands can themselves be JOIN expressions, allowing representation of complex join trees. Use getLeftMostJoinExpr() to traverse to the leftmost join in a nested structure.

PostgreSQL-specific: Supports USING clause aliases via getJoin_using_alias().

The class implements IRelation and maintains a list of available attributes from both sides of the join via getAttributes().

Represents join table in parse tree.

Field Summary

Fields

Modifier and Type	Field	Description
TExpression	onCondition	on condition;
EJoinType	original_jontype
TObjectNameList	usingColumns	using (column list)

Fields inherited from class gudusoft.gsqlparser.nodes.TParseTreeNode

dbvendor, doubleLinkedTokenListToString, nodeActionAppend, nodeActionInsert, nodeActionRemove, nodeActionUnknown, nodeActionUpdate, nodeActionUpdateText, nodeChangeEndToken, nodeChangeStartToken

Constructor Summary

Constructors

Constructor	Description
TJoinExpr()

Method Summary

Modifier and Type	Method	Description
void	accept(TParseTreeVisitor v)	Accept a visitor
void	acceptChildren(TParseTreeVisitor v)	Accept a visitor to iterate this class and sub-nodes of this class
ArrayList<TAttributeNode>	getAttributes()	每个 relation 包含的 attributes 当它为 base table 时，这些 attributes 的来源有三种可能 1.
TAliasClause	getJoin_using_alias()	Postgres: USING ( join_column [, ...] ) [ AS join_using_alias ]
EJoinType	getJointype()
TJoinExpr	getLeftMostJoinExpr()
TFromTable	getLeftOperand()	This method is used by parser, do not use it in your code.
TTable	getLeftTable()
TExpression	getMatchCondition()
int	getNestedParen()
TExpression	getOnCondition()
String	getRelationName()
TFromTable	getRightOperand()	This method is used by parser, do not use it in your code.
TTable	getRightTable()
TObjectNameList	getUsingColumns()
void	incNestedParen()
void	init(Object arg1)	Initialize a query tree node.
void	init(Object arg1, Object arg2)
void	initAttributes(int roundNo)
void	setJoinCondition(TDummy pDummy)
void	setJoinCondition(TExpression onCondition)
void	setJointype(EJoinType jointype)
void	setLeftOperand(TFromTable leftOperand)	This method is used by parser, do not use it in your code.
void	setLeftTable(TTable leftTable)
void	setMatchCondition(TExpression matchCondition)
void	setNestedParen(int nestedParen)
void	setOnCondition(TExpression onCondition)
void	setRightOperand(TFromTable rightOperand)	This method is used by parser, do not use it in your code.
void	setRightTable(TTable rightTable)
void	setUsingColumns(TObjectNameList usingColumns)
int	size()

Methods inherited from class gudusoft.gsqlparser.nodes.TNodeWithAliasClause

getAliasClause, setAliasClause, toString

Methods inherited from class gudusoft.gsqlparser.nodes.TParseTreeNode

addAllMyTokensToTokenList, addToTokenChain, appendNewNode, calculateTokenCount, doAppendNewNode, doParse, fastSetString, getAnchorNode, getColumnNo, getCommentAfterNode, getCommentBeforeNode, getCompactString, getDummyTag, getEndToken, getEvaluateDatatype, getEvalValue, getGsqlparser, getLineNo, getLocation, getMd5, getNodeStatus, getNodeType, getParentObjectName, getPlainText, getStartToken, getTokenCount, hasNext, init, init, init, init, insertAfterAToken, insertNewNodeBeforeMe, isChanged, isTokensInChain, next, refreshAllNodesTokenCount, remove, removeAllMyTokensFromTokenList, removeTokens, removeTokensBetweenNodes, removeTokensBetweenToken, replaceWithNewNode, resetIterator, setAnchorNode, setChanged, setDummyTag, setEndToken, setEndToken, setEndToken, setEndToken, setEndToken, setEndTokenDirectly, setEvaluateDatatype, setEvalValue, setGsqlparser, setIncludingComment, setLocation, setNewSubNode, setNodeStatus, setNodeType, setParent, setPlainText, setStartToken, setStartToken, setStartToken, setStartToken, setStartTokenDirectly, setString, setString2, subNodeInNode, toScript, toString2

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining

Field Details

usingColumns

public TObjectNameList usingColumns

using (column list)

onCondition

public TExpression onCondition

on condition;

original_jontype

public EJoinType original_jontype

Constructor Details

TJoinExpr

public TJoinExpr()

Method Details

getJoin_using_alias

public TAliasClause getJoin_using_alias()

Postgres: USING ( join_column [, ...] ) [ AS join_using_alias ]

Returns:

initAttributes

public void initAttributes(int roundNo)

getAttributes

public ArrayList<TAttributeNode> getAttributes()

Description copied from interface: IRelation

每个 relation 包含的 attributes 当它为 base table 时，这些 attributes 的来源有三种可能 1. 来自数据库的 metadata，第一次 resolve 时就可以获取，来自 sqlenv 2. 来自 create table ddl，第一次 resolve 时就可以获取，来自 sqlenv 3. 来自 sql script，第二次 resolve 时，来自relation的 referenceAttribute 属性。 第一、二中来源是可靠的来源，attributes应该是完整的，第三种推断自 sql script，attributes很可能是不完整的。

Specified by:

getAttributes in interface IRelation

Returns:

getRelationName

public String getRelationName()

Specified by:

getRelationName in interface IRelation

size

public int size()

Specified by:

size in interface IRelation

setLeftTable

public void setLeftTable(TTable leftTable)

setRightTable

public void setRightTable(TTable rightTable)

getLeftTable

public TTable getLeftTable()

getRightTable

public TTable getRightTable()

incNestedParen

public void incNestedParen()

getNestedParen

public int getNestedParen()

getUsingColumns

public TObjectNameList getUsingColumns()

getOnCondition

public TExpression getOnCondition()

getJointype

public EJoinType getJointype()

setJointype

public void setJointype(EJoinType jointype)

getLeftOperand

public TFromTable getLeftOperand()

This method is used by parser, do not use it in your code. After parsing, you can use getLeftTable() instead.

getRightOperand

public TFromTable getRightOperand()

This method is used by parser, do not use it in your code. After parsing, you can use getRightTable() instead.

setLeftOperand

public void setLeftOperand(TFromTable leftOperand)

This method is used by parser, do not use it in your code. After parsing, you can use setLeftTable() instead.

setRightOperand

public void setRightOperand(TFromTable rightOperand)

This method is used by parser, do not use it in your code. After parsing, you can use setRightTable() instead.

init

public void init(Object arg1)

Description copied from class: TParseTreeNode

Initialize a query tree node. Used internally

Overrides:

init in class TParseTreeNode

Parameters:

arg1 - first argument

init

public void init(Object arg1,
 Object arg2)

Overrides:

init in class TParseTreeNode

setJoinCondition

public void setJoinCondition(TDummy pDummy)

setJoinCondition

public void setJoinCondition(TExpression onCondition)

getLeftMostJoinExpr

public TJoinExpr getLeftMostJoinExpr()

setNestedParen

public void setNestedParen(int nestedParen)

setUsingColumns

public void setUsingColumns(TObjectNameList usingColumns)

setOnCondition

public void setOnCondition(TExpression onCondition)

getMatchCondition

public TExpression getMatchCondition()

setMatchCondition

public void setMatchCondition(TExpression matchCondition)

accept

public void accept(TParseTreeVisitor v)

Description copied from class: TParseTreeNode

Accept a visitor

Specified by:

accept in interface Visitable

Overrides:

accept in class TParseTreeNode

Parameters:

v - visitor is a descendant class of TParseTreeVisitor

acceptChildren

public void acceptChildren(TParseTreeVisitor v)

Description copied from class: TParseTreeNode

Accept a visitor to iterate this class and sub-nodes of this class

Specified by:

acceptChildren in interface Visitable

Overrides:

acceptChildren in class TParseTreeNode

Parameters:

v - visitor is a descendant class of TParseTreeVisitor