Package gudusoft.gsqlparser.resolver2.namespace

Class SubqueryNamespace

Object

gudusoft.gsqlparser.resolver2.namespace.AbstractNamespace

gudusoft.gsqlparser.resolver2.namespace.SubqueryNamespace

All Implemented Interfaces:

INamespace

public class SubqueryNamespace
extends AbstractNamespace

Namespace representing a subquery. Provides columns from the subquery's SELECT list. Example: FROM (SELECT id, name FROM users) AS t ^^^^^^^^^^^^^^^^^^^^^^^^ SubqueryNamespace exposes columns: id, name

Field Summary

Fields inherited from class gudusoft.gsqlparser.resolver2.namespace.AbstractNamespace

columnSources, columnSourcesWithRefs, guessColumnStrategy, nameMatcher, node, referenceTraceabilityEnabled, validated

Constructor Summary

Constructors

Constructor	Description
SubqueryNamespace(TSelectSqlStatement subquery, String alias)
SubqueryNamespace(TSelectSqlStatement subquery, String alias, INameMatcher nameMatcher)
SubqueryNamespace(TSelectSqlStatement subquery, String alias, INameMatcher nameMatcher, boolean fromTableFunction)

Method Summary

Modifier and Type	Method	Description
boolean	addInferredColumn(String columnName, double confidence, String evidence)	Add an inferred column to this namespace.
protected void	doValidate()	Subclasses override this to perform actual validation logic.
List<TTable>	getAllFinalTables()	Get all final physical tables this namespace depends on.
String	getDisplayName()	Get a display name for this namespace (for debugging/error messages)
TTable	getFinalTable()	Get the final physical table this namespace represents.
Set<String>	getInferredColumns()	Get all columns that were inferred (not from SELECT list directly).
TSelectSqlStatement	getSelectStatement()	Get the underlying SELECT statement for this namespace.
TTable	getSourceTable()	Get the TTable that this namespace is associated with.
TSQLEnv	getSqlEnv()	Get the TSQLEnv used for metadata lookup.
TResultColumn	getStarColumn()	Get the first star column (TResultColumn) from this subquery's SELECT list.
TSelectSqlStatement	getSubquery()
boolean	hasAmbiguousStar()	Check if this subquery has an unqualified star with multiple tables.
ColumnLevel	hasColumn(String columnName)	Check if a column exists in this namespace.
boolean	hasStarColumn()	Check if this namespace contains a star column (SELECT *).
boolean	isFromTableFunction()	Returns true if this namespace was created from a TABLE function's subquery.
ColumnSource	resolveColumn(String columnName)	Resolve a column name to its source.
ColumnSource	resolveColumnInFromScope(String columnName)	Resolve a column in the FROM scope (child namespaces).
void	setSourceTable(TTable sourceTable)	Set the TTable that wraps this subquery.
void	setSqlEnv(TSQLEnv sqlEnv)	Set the TSQLEnv for metadata lookup.
boolean	supportsDynamicInference()	Check if this namespace supports dynamic column inference.
String	toString()

Methods inherited from class gudusoft.gsqlparser.resolver2.namespace.AbstractNamespace

addColumnSource, addColumnSource, enableReferenceTraceability, ensureValidated, getAllColumnSources, getAllUniqueColumns, getColumnReferences, getColumnSourceWithReferences, getGuessColumnStrategy, getNameMatcher, getNode, isReferenceTraceabilityEnabled, isValidated, setGuessColumnStrategy, validate

Methods inherited from class java.lang.Object

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

Methods inherited from interface gudusoft.gsqlparser.resolver2.namespace.INamespace

resolveColumnPath

Constructor Details

SubqueryNamespace

public SubqueryNamespace(TSelectSqlStatement subquery,
 String alias,
 INameMatcher nameMatcher)

SubqueryNamespace

public SubqueryNamespace(TSelectSqlStatement subquery,
 String alias,
 INameMatcher nameMatcher,
 boolean fromTableFunction)

SubqueryNamespace

public SubqueryNamespace(TSelectSqlStatement subquery,
 String alias)

Method Details

isFromTableFunction

public boolean isFromTableFunction()

Returns true if this namespace was created from a TABLE function's subquery.

setSourceTable

public void setSourceTable(TTable sourceTable)

Set the TTable that wraps this subquery. Used by ScopeBuilder for legacy sync support.

Parameters:

sourceTable - the TTable that contains this subquery

getSourceTable

public TTable getSourceTable()

Description copied from interface: INamespace

Get the TTable that this namespace is associated with. Used for legacy sync to set TObjectName.sourceTable. For TableNamespace: returns the table itself For SubqueryNamespace: returns the TTable wrapping the subquery For CTENamespace: returns the CTE referencing table For others: returns null

Returns:

The source TTable, or null if not applicable

setSqlEnv

public void setSqlEnv(TSQLEnv sqlEnv)

Set the TSQLEnv for metadata lookup. Used when resolving star columns to find which columns exist in underlying tables.

Parameters:

sqlEnv - the SQL environment containing table metadata

getSqlEnv

public TSQLEnv getSqlEnv()

Get the TSQLEnv used for metadata lookup.

Returns:

the SQL environment, or null if not set

getDisplayName

public String getDisplayName()

Description copied from interface: INamespace

Get a display name for this namespace (for debugging/error messages)

getFinalTable

public TTable getFinalTable()

Description copied from interface: INamespace

Get the final physical table this namespace represents. For tables: returns the table itself For subqueries/CTEs: recursively traces back to physical table(s)

Returns:

Physical table, or null if not determinable

getAllFinalTables

public List<TTable> getAllFinalTables()

Description copied from interface: INamespace

Get all final physical tables this namespace depends on. For simple table namespace: returns single table For subquery/CTE: returns all tables in the query tree

Specified by:

getAllFinalTables in interface INamespace

Overrides:

getAllFinalTables in class AbstractNamespace

Returns:

List of all physical tables

doValidate

protected void doValidate()

Description copied from class: AbstractNamespace

Subclasses override this to perform actual validation logic.

Specified by:

doValidate in class AbstractNamespace

hasColumn

public ColumnLevel hasColumn(String columnName)

Description copied from interface: INamespace

Check if a column exists in this namespace. Returns a three-level answer: EXISTS, MAYBE, NOT_EXISTS

Specified by:

hasColumn in interface INamespace

Overrides:

hasColumn in class AbstractNamespace

Parameters:

columnName - Column name to check

Returns:

Column existence level

getSubquery

public TSelectSqlStatement getSubquery()

getSelectStatement

public TSelectSqlStatement getSelectStatement()

Description copied from interface: INamespace

Get the underlying SELECT statement for this namespace. For CTENamespace: returns the CTE's subquery For SubqueryNamespace: returns the subquery For TableNamespace: returns null

Returns:

the SELECT statement, or null if not applicable

hasStarColumn

public boolean hasStarColumn()

Description copied from interface: INamespace

Check if this namespace contains a star column (SELECT *). Used to identify namespaces that may need star column inference.

Returns:

true if the namespace has SELECT *, false otherwise

getStarColumn

public TResultColumn getStarColumn()

Get the first star column (TResultColumn) from this subquery's SELECT list. Used to track the definition node for columns inferred from the star.

Returns:

The star column, or null if no star column exists

hasAmbiguousStar

public boolean hasAmbiguousStar()

Check if this subquery has an unqualified star with multiple tables. In this case, columns are ambiguous and should NOT be auto-resolved. Example: SELECT * FROM table_a, table_c -- ambiguous, columns could come from either table SELECT ta.* FROM table_a ta, table_c tc -- NOT ambiguous, star is qualified SELECT * FROM table_a JOIN table_c ON ... -- ambiguous, columns from both tables Uses getRelations() and TJoinExpr to properly count tables in JOINs.

supportsDynamicInference

public boolean supportsDynamicInference()

Description copied from interface: INamespace

Check if this namespace supports dynamic column inference. DynamicStarSource and similar namespaces return true.

Returns:

true if this namespace can have columns added dynamically

addInferredColumn

public boolean addInferredColumn(String columnName,
 double confidence,
 String evidence)

Description copied from interface: INamespace

Add an inferred column to this namespace. Used by star column push-down to add columns discovered from outer queries.

Parameters:

columnName - the column name to add

confidence - the confidence score (0.0 to 1.0)

evidence - description of why this column was inferred

Returns:

true if the column was added, false if already exists

getInferredColumns

public Set<String> getInferredColumns()

Description copied from interface: INamespace

Get all columns that were inferred (not from SELECT list directly). These are columns discovered through star column push-down.

Returns:

set of inferred column names, empty if none

resolveColumn

public ColumnSource resolveColumn(String columnName)

Description copied from interface: INamespace

Resolve a column name to its source.

Specified by:

resolveColumn in interface INamespace

Overrides:

resolveColumn in class AbstractNamespace

Parameters:

columnName - Column name to resolve

Returns:

ColumnSource if found, null otherwise

resolveColumnInFromScope

public ColumnSource resolveColumnInFromScope(String columnName)

Resolve a column in the FROM scope (child namespaces). This finds where a column originates from in the FROM clause tables/subqueries.

Unlike resolveColumn() which returns columns from THIS subquery's SELECT list, this method looks into the FROM clause to find the underlying definition.

IMPORTANT: For TableNamespace, this only returns columns that exist in actual metadata (from DDL or SQLEnv). It does NOT use inferred columns. This is critical for multi-table star resolution where we need to know which table actually has the column based on metadata, not inference.

Parameters:

columnName - The column name to find

Returns:

ColumnSource from the FROM clause, or null if not found

toString

public String toString()

Overrides:

toString in class AbstractNamespace