gudusoft.gsqlparser.ir.semantic.joinanalysis

Class JoinEndpoint

Object

gudusoft.gsqlparser.ir.semantic.joinanalysis.JoinEndpoint

public final class JoinEndpoint
extends Object

One input side of a JoinEntity. A join never references a bare alias directly; it references a JoinEndpoint so that the left side of a left-deep chain (t1 JOIN t2 JOIN t3) can be modelled as the accumulated JoinEndpointKind.JOIN_RESULT of the prior joins rather than a single relation.

• A JoinEndpointKind.RELATION endpoint carries the FROM-clause alias and the relation's qualifiedName (e.g. t1).
• A JoinEndpointKind.JOIN_RESULT endpoint carries the producingJoinOrder (the JoinEntity.getOrder() of the join that produced this result) and the immutable list of contributingAliases flowing through it.

Immutable. Introduced by join-analysis slice 162 (S1).

Field Summary

Fields

Modifier and Type	Field and Description
static int	NO_INSTANCE_ID Sentinel for "no stable relation instance id" (slice 179).

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
String	getAlias() Non-null only for JoinEndpointKind.RELATION.
List<String>	getContributingAliases() Never null; empty for JoinEndpointKind.RELATION.
int	getInstanceId() Stable relation instance id (slice 179, R4) for a RELATION endpoint — matches RelationSource.getInstanceId().
JoinEndpointKind	getKind()
int	getProducingJoinOrder() Meaningful only for JoinEndpointKind.JOIN_RESULT; else -1.
String	getQualifiedName() May be null even for JoinEndpointKind.RELATION.
int	hashCode()
static JoinEndpoint	joinResult(int producingJoinOrder, List<String> contributingAliases) The accumulated result of prior joins in a left-deep chain.
static JoinEndpoint	relation(String alias, String qualifiedName) A single FROM-clause relation with no stable instance id.
static JoinEndpoint	relation(String alias, String qualifiedName, int instanceId) A single FROM-clause relation carrying its stable instanceId (slice 179, R4) — the same per-block FROM-order ordinal as the matching RelationSource.getInstanceId(), so an endpoint links to its exact relation instance without alias-keying.
String	toString()

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

NO_INSTANCE_ID

public static final int NO_INSTANCE_ID

Sentinel for "no stable relation instance id" (slice 179).

See Also:

Constant Field Values

Method Detail

relation

public static JoinEndpoint relation(String alias,
                                    String qualifiedName)

A single FROM-clause relation with no stable instance id. alias must be non-empty; qualifiedName may be null when the relation has no resolvable name (e.g. an unaliased derived table).

relation

public static JoinEndpoint relation(String alias,
                                    String qualifiedName,
                                    int instanceId)

A single FROM-clause relation carrying its stable instanceId (slice 179, R4) — the same per-block FROM-order ordinal as the matching RelationSource.getInstanceId(), so an endpoint links to its exact relation instance without alias-keying.

joinResult

public static JoinEndpoint joinResult(int producingJoinOrder,
                                      List<String> contributingAliases)

The accumulated result of prior joins in a left-deep chain.

Parameters:

producingJoinOrder - the JoinEntity.getOrder() of the join producing this result

contributingAliases - aliases flowing through this result (may be empty, never null)

getKind

public JoinEndpointKind getKind()

getAlias

public String getAlias()

Non-null only for JoinEndpointKind.RELATION.

getQualifiedName

public String getQualifiedName()

May be null even for JoinEndpointKind.RELATION.

getInstanceId

public int getInstanceId()

Stable relation instance id (slice 179, R4) for a RELATION endpoint — matches RelationSource.getInstanceId(). NO_INSTANCE_ID for JOIN_RESULT endpoints or when not assigned.

getProducingJoinOrder

public int getProducingJoinOrder()

Meaningful only for JoinEndpointKind.JOIN_RESULT; else -1.

getContributingAliases

public List<String> getContributingAliases()

Never null; empty for JoinEndpointKind.RELATION.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object