org.eigenbase.sql.validate
Class JoinScope

java.lang.Object
  org.eigenbase.sql.validate.DelegatingScope
      org.eigenbase.sql.validate.ListScope
          org.eigenbase.sql.validate.JoinScope

All Implemented Interfaces:

SqlValidatorScope

public class JoinScope
extends ListScope

The name-resolution context for expression inside a JOIN clause. The objects visible are the joined table expressions, and those inherited from the parent scope.

Consider "SELECT * FROM (A JOIN B ON {exp1}) JOIN C ON {exp2}". {exp1} is resolved in the join scope for "A JOIN B", which contains A and B but not C.

Since:

Mar 25, 2003

Version:

$Id: //open/dev/farrago/src/org/eigenbase/sql/validate/JoinScope.java#9 $

Author:

jhyde

Field Summary

private SqlJoin	join
private SqlValidatorScope	usingScope

Fields inherited from class org.eigenbase.sql.validate.ListScope

children, childrenNames

Fields inherited from class org.eigenbase.sql.validate.DelegatingScope

parent, validator

Constructor Summary

JoinScope(SqlValidatorScope parent, SqlValidatorScope usingScope, SqlJoin join)
Creates a JoinScope.

Method Summary

void	addChild(SqlValidatorNamespace ns, String alias) Registers a relation in this scope.
SqlNode	getNode() Returns the root node of this scope.
SqlValidatorScope	getUsingScope() Returns the scope which is used for resolving USING clause.
SqlWindow	lookupWindow(String name) Finds a window with a given name.

Methods inherited from class org.eigenbase.sql.validate.ListScope

findAliases, findAllColumnNames, findQualifyingTableName, getChild, getChildren, resolve, resolveColumn

Methods inherited from class org.eigenbase.sql.validate.DelegatingScope

addColumnNames, fullyQualify, getMonotonicity, getOperandScope, getOrderList, getParent, getValidator, validateExpr

Methods inherited from class java.lang.Object

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

Field Detail

usingScope

private final SqlValidatorScope usingScope

join

private final SqlJoin join

Constructor Detail

JoinScope

JoinScope(SqlValidatorScope parent,
          SqlValidatorScope usingScope,
          SqlJoin join)

Creates a JoinScope.

Parameters:

parent - Parent scope

usingScope - Scope for resolving USING clause

join - Call to JOIN operator

Method Detail

getNode

public SqlNode getNode()

Description copied from interface: SqlValidatorScope

Returns the root node of this scope.

addChild

public void addChild(SqlValidatorNamespace ns,
                     String alias)

Description copied from interface: SqlValidatorScope

Registers a relation in this scope.

Specified by:

addChild in interface SqlValidatorScope

Overrides:

addChild in class ListScope

Parameters:

ns - Namespace representing the result-columns of the relation

alias - Alias with which to reference the relation, must not be null

lookupWindow

public SqlWindow lookupWindow(String name)

Description copied from interface: SqlValidatorScope

Finds a window with a given name. Returns null if not found.

Specified by:

lookupWindow in interface SqlValidatorScope

Overrides:

lookupWindow in class DelegatingScope

getUsingScope

public SqlValidatorScope getUsingScope()

Returns the scope which is used for resolving USING clause.