gudusoft.gsqlparser.resolver2.expansion

Class ExpansionResult

Object

gudusoft.gsqlparser.resolver2.expansion.ExpansionResult

public class ExpansionResult
extends Object

Result of star column expansion.

Tracks: - Which star columns were expanded - Which star columns could not be expanded (and why) - Non-star columns (passed through) - Statistics about the expansion

Example:

 SELECT t1.*, t2.id, t3.*
 FROM t1 JOIN t2 JOIN t3

 ExpansionResult:
 - expandedStars: {t1.* -> [t1.id, t1.name], t3.* -> [t3.id, t3.status]}
 - nonStarColumns: [t2.id]
 - unexpandableStars: {}
 

Constructor Summary

Constructors

Constructor and Description
ExpansionResult()

Method Summary

Modifier and Type	Method and Description
void	addExpandedStar(TResultColumn starColumn, List<ExpandedColumn> expandedColumns) Add a successfully expanded star column.
void	addNonStarColumn(TResultColumn column) Add a non-star column.
void	addUnexpandableStar(TResultColumn starColumn, String reason) Add a star column that could not be expanded.
List<ExpandedColumn>	getAllExpandedColumns() Get all expanded columns (flattened list).
int	getExpandedStarCount() Get the number of star columns that were expanded.
Map<TResultColumn,List<ExpandedColumn>>	getExpandedStars() Get all expanded stars.
List<TResultColumn>	getNonStarColumns() Get all non-star columns.
String	getStatistics() Get statistics about the expansion.
int	getTotalColumnCount() Get the total number of columns after expansion.
int	getUnexpandableStarCount() Get the number of star columns that could not be expanded.
Map<TResultColumn,String>	getUnexpandableStars() Get all unexpandable stars.
boolean	hasExpandedStars() Check if any stars were expanded.
boolean	isFullyExpanded() Check if all stars were successfully expanded.
String	toString()

Methods inherited from class Object

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

Constructor Detail

ExpansionResult

public ExpansionResult()

Method Detail

addExpandedStar

public void addExpandedStar(TResultColumn starColumn,
                            List<ExpandedColumn> expandedColumns)

Add a successfully expanded star column.

Parameters:

starColumn - the original star column

expandedColumns - the expanded columns

addUnexpandableStar

public void addUnexpandableStar(TResultColumn starColumn,
                                String reason)

Add a star column that could not be expanded.

Parameters:

starColumn - the star column

reason - why it could not be expanded

addNonStarColumn

public void addNonStarColumn(TResultColumn column)

Add a non-star column.

Parameters:

column - the non-star column

getExpandedStars

public Map<TResultColumn,List<ExpandedColumn>> getExpandedStars()

Get all expanded stars.

Returns:

map of star column to expanded columns

getUnexpandableStars

public Map<TResultColumn,String> getUnexpandableStars()

Get all unexpandable stars.

Returns:

map of star column to reason

getNonStarColumns

public List<TResultColumn> getNonStarColumns()

Get all non-star columns.

Returns:

list of non-star columns

getAllExpandedColumns

public List<ExpandedColumn> getAllExpandedColumns()

Get all expanded columns (flattened list).

Returns:

all expanded columns from all stars

getTotalColumnCount

public int getTotalColumnCount()

Get the total number of columns after expansion. This includes expanded star columns and non-star columns.

Returns:

total column count

getExpandedStarCount

public int getExpandedStarCount()

Get the number of star columns that were expanded.

Returns:

expanded star count

getUnexpandableStarCount

public int getUnexpandableStarCount()

Get the number of star columns that could not be expanded.

Returns:

unexpandable star count

isFullyExpanded

public boolean isFullyExpanded()

Check if all stars were successfully expanded.

Returns:

true if no unexpandable stars, false otherwise

hasExpandedStars

public boolean hasExpandedStars()

Check if any stars were expanded.

Returns:

true if at least one star was expanded

getStatistics

public String getStatistics()

Get statistics about the expansion.

Returns:

statistics string

toString

public String toString()

Overrides:

toString in class Object