Package io.trino.sql.analyzer

Class Scope

java.lang.Object

io.trino.sql.analyzer.Scope

@Immutable
public class Scope
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Scope.AsteriskedIdentifierChainBasis
static final class	Scope.Builder

Method Summary

Modifier and Type	Method	Description
static Scope.Builder	builder()
static Scope	create()
ResolvedField	getField(int index)
Optional<Scope>	getLocalParent()
int	getLocalScopeFieldCount()
Optional<WithQuery>	getNamedQuery(String name)
Optional<Scope>	getOuterQueryParent()
Scope	getQueryBoundaryScope()
RelationId	getRelationId()
RelationType	getRelationType()
boolean	hasOuterParent(Scope parent)
boolean	isColumnReference(QualifiedName name)
boolean	isLocalScope(Scope other)
Optional<Scope.AsteriskedIdentifierChainBasis>	resolveAsteriskedIdentifierChainBasis(QualifiedName identifierChain, AllColumns selectItem)	This method analyzes asterisked identifier chain in 'all fields reference', according to SQL standard.
ResolvedField	resolveField(Expression expression, QualifiedName name)
String	toString()
Optional<ResolvedField>	tryResolveField(Expression expression)
Optional<ResolvedField>	tryResolveField(Expression node, QualifiedName name)
Scope	withRelationType(RelationType relationType)

Methods inherited from class java.lang.Object

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

Method Details

create

public static Scope create()

builder

public static Scope.Builder builder()

withRelationType

public Scope withRelationType(RelationType relationType)

getQueryBoundaryScope

public Scope getQueryBoundaryScope()

getOuterQueryParent

public Optional<Scope> getOuterQueryParent()

hasOuterParent

public boolean hasOuterParent(Scope parent)

getLocalParent

public Optional<Scope> getLocalParent()

getLocalScopeFieldCount

public int getLocalScopeFieldCount()

getRelationId

public RelationId getRelationId()

getRelationType

public RelationType getRelationType()

resolveAsteriskedIdentifierChainBasis

public Optional<Scope.AsteriskedIdentifierChainBasis> resolveAsteriskedIdentifierChainBasis(QualifiedName identifierChain,
 AllColumns selectItem)

This method analyzes asterisked identifier chain in 'all fields reference', according to SQL standard. The following rules are applied: 1. if the identifier chain's length is lower than 4, it is attempted to resolve it as a table reference, either in the local scope or in outer scope. 2. if the identifier chain's length is greater than 1, it is attempted to match the chain's prefix of length 2 to a field of type Row, either in the local scope or in outer scope. Any available match in the innermost scope is picked and the 'identifier chain basis' is defined. If more than one basis is defined, it results in a failure (ambiguous identifier chain).

NOTE: only ambiguity between table reference and field reference is currently detected. If two or more tables in the same scope match the identifier chain, they are indistinguishable in current Scope implementation, and such query results in returning fields from all of those tables. If two or more fields in the same scope match the identifier chain, such query will fail later during analysis.

NOTE: Although references to outer scope tables are found, referencing all fields from outer scope tables is not yet supported.

isLocalScope

public boolean isLocalScope(Scope other)

resolveField

public ResolvedField resolveField(Expression expression,
 QualifiedName name)

tryResolveField

public Optional<ResolvedField> tryResolveField(Expression expression)

tryResolveField

public Optional<ResolvedField> tryResolveField(Expression node,
 QualifiedName name)

getField

public ResolvedField getField(int index)

isColumnReference

public boolean isColumnReference(QualifiedName name)

getNamedQuery

public Optional<WithQuery> getNamedQuery(String name)

toString

public String toString()

Overrides:

toString in class Object