gudusoft.gsqlparser.nodes

Class TResultColumnList

Object

gudusoft.gsqlparser.nodes.TParseTreeNode

gudusoft.gsqlparser.nodes.TParseTreeNodeList<TResultColumn>

gudusoft.gsqlparser.nodes.TResultColumnList

All Implemented Interfaces:

Visitable, Iterable<TResultColumn>, Iterator<TSourceToken>

public class TResultColumnList
extends TParseTreeNodeList<TResultColumn>

Field Summary

Fields inherited from class gudusoft.gsqlparser.nodes.TParseTreeNodeList

modCount

Fields inherited from class gudusoft.gsqlparser.nodes.TParseTreeNode

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

Constructor Summary

Constructors

Constructor and Description
TResultColumnList()

Method Summary

Modifier and Type	Method and 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
void	addResultColumn(String ptext) Used to add a result column manually when re-construct a select list There must exist at least one column in column list in order to this function.
void	addResultColumn(TResultColumn resultColumn) Add a ResultColumn to the list
void	doParse(TCustomSqlStatement psql, ESqlClause plocation) analyze this node
TResultColumn	findLateralAliasDefinition(EDbVendor vendor, TObjectName reference) Find the SELECT-list column alias that an unqualified reference elsewhere in the same SELECT block binds to — a "lateral column alias" reference such as Snowflake's SELECT val*2 AS derived_col FROM t WHERE derived_col > 1.
TSourceToken	getEndToken() The last token of the node
TResultColumn	getResultColumn(int position) Get a ResultColumn from a column position (0-based) in the list
ArrayList<TResultColumn>	getSortedColumns()
TSourceToken	getStartToken() In teradata, the whole result column can be null, so this result column should be ingored when get start token in result column list.
TParseTreeNode	removeItem(int index)
void	removeResultColumn(int index)

Methods inherited from class gudusoft.gsqlparser.nodes.TParseTreeNodeList

addAll, addElement, addNode, clear, elementAt, getElement, indexOf, init, init, init, init, insertElementAt, isListSeparatedByComma, iterator, removeElement, removeElementAt, removeElementWithoutSyncTokens, setListSeparatedByComma, size, TParseTreeNodeList

Methods inherited from class gudusoft.gsqlparser.nodes.TParseTreeNode

addAllMyTokensToTokenList, addToTokenChain, appendNewNode, calculateTokenCount, doAppendNewNode, fastSetString, getAnchorNode, getColumnNo, getCommentAfterNode, getCommentBeforeNode, getCompactString, getDummyTag, getEvaluateDatatype, getEvalValue, getGsqlparser, getLineNo, getLocation, getMd5, getNodeStatus, getNodeType, getParentObjectName, getPlainText, getTokenCount, hasNext, init, init, 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, toString, toString2

Methods inherited from class Object

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

Methods inherited from interface Iterable

forEach, spliterator

Methods inherited from interface Iterator

forEachRemaining

Constructor Detail

TResultColumnList

public TResultColumnList()

Method Detail

getSortedColumns

public ArrayList<TResultColumn> getSortedColumns()

removeResultColumn

public void removeResultColumn(int index)

removeItem

public TParseTreeNode removeItem(int index)

Overrides:

removeItem in class TParseTreeNodeList<TResultColumn>

addResultColumn

public void addResultColumn(String ptext)

Used to add a result column manually when re-construct a select list There must exist at least one column in column list in order to this function.

Parameters:

ptext -

addResultColumn

public void addResultColumn(TResultColumn resultColumn)

Add a ResultColumn to the list

Parameters:

resultColumn - The ResultColumn to add to the list

getResultColumn

public TResultColumn getResultColumn(int position)

Get a ResultColumn from a column position (0-based) in the list

Parameters:

position - The ResultColumn to get from the list (1-based)

Returns:

the column at that position.

getStartToken

public TSourceToken getStartToken()

In teradata, the whole result column can be null, so this result column should be ingored when get start token in result column list.

Overrides:

getStartToken in class TParseTreeNodeList<TResultColumn>

Returns:

getEndToken

public TSourceToken getEndToken()

Description copied from class: TParseTreeNode

The last token of the node

Overrides:

getEndToken in class TParseTreeNodeList<TResultColumn>

Returns:

the last token of node

doParse

public void doParse(TCustomSqlStatement psql,
                    ESqlClause plocation)

Description copied from class: TParseTreeNodeList

analyze this node

Overrides:

doParse in class TParseTreeNodeList<TResultColumn>

Parameters:

psql - SQL statement this node belongs to

plocation - SQL clause this node belongs to

findLateralAliasDefinition

public TResultColumn findLateralAliasDefinition(EDbVendor vendor,
                                                TObjectName reference)

Find the SELECT-list column alias that an unqualified reference elsewhere in the same SELECT block binds to — a "lateral column alias" reference such as Snowflake's SELECT val*2 AS derived_col FROM t WHERE derived_col > 1.

This is the SINGLE definition of that binding rule. Both consumers delegate here so the two paths can never drift apart:

• publish — Phase 1 TCustomSqlStatement.linkColumnToTable(), which sets sourceColumn and deliberately leaves sourceTable null;
• lookup — resolver2 TSQLResolver2.handleSelectListAliasResolution().

Fixing one and not the other yields a reference whose sourceColumn is the alias while its sourceTable is a FROM-clause table that has no such column — a wrong answer with nothing to flag it (MantisBT 4659).

The rule is vendor-gated twice: the dialect must support lateral column aliases at all (TBaseType.isSupportLateralColumn(gudusoft.gsqlparser.EDbVendor)), and it must not forbid referencing a SELECT-list alias outside ORDER BY (TSQLEnv.isAliasReferenceForbidden). Oracle, MySQL, PostgreSQL, BigQuery and friends forbid it, so for them such a name is NOT an alias reference and this returns null.

The reference must also appear textually AFTER the alias it binds to. That ordering rule is what keeps a column inside the alias's own defining expression (CAST(id AS DECIMAL) AS id) bound to the real table column rather than to the alias being defined.

Parameters:

vendor - the dialect of the enclosing statement

reference - an unqualified column reference from the same SELECT block

Returns:

the defining TResultColumn, or null when this is not a lateral column alias reference

accept

public void accept(TParseTreeVisitor v)

Description copied from class: TParseTreeNode

Accept a visitor

Specified by:

accept in interface Visitable

Overrides:

accept in class TParseTreeNodeList<TResultColumn>

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 TParseTreeNodeList<TResultColumn>

Parameters:

v - visitor is a descendant class of TParseTreeVisitor