org.eigenbase.sql.validate
Class AliasNamespace

java.lang.Object
  org.eigenbase.sql.validate.AbstractNamespace
      org.eigenbase.sql.validate.AliasNamespace

All Implemented Interfaces:

SqlValidatorNamespace

public class AliasNamespace
extends AbstractNamespace

Namespace for an AS t(c1, c2, ...) clause.

A namespace is necessary only if there is a column list, in order to re-map column names; a relation AS t clause just uses the same namespace as relation.

Since:

October 9, 2008

Version:

$Id: //open/dev/farrago/src/org/eigenbase/sql/validate/AliasNamespace.java#4 $

Author:

jhyde

Field Summary

protected SqlCall

call

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

enclosingNode, rowType, validator

Constructor Summary

protected

AliasNamespace(SqlValidatorImpl validator, SqlCall call, SqlNode enclosingNode) Creates an AliasNamespace.

Method Summary

SqlNode	getNode() Returns the parse tree node at the root of this namespace.
String	translate(String name) Translates a field name to the name in the underlying namespace.
protected RelDataType	validateImpl() Validates this scope and returns the type of the records it returns.

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

fieldExists, getEnclosingNode, getMonotonicExprs, getMonotonicity, getRowType, getRowTypeSansSystemColumns, getTable, getValidator, isWrapperFor, lookupChild, makeNullable, setRowType, unwrap, validate

Methods inherited from class java.lang.Object

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

Field Detail

call

protected final SqlCall call

Constructor Detail

AliasNamespace

protected AliasNamespace(SqlValidatorImpl validator,
                         SqlCall call,
                         SqlNode enclosingNode)

Creates an AliasNamespace.

Parameters:

validator - Validator

call - Call to AS operator

enclosingNode - Enclosing node

Method Detail

validateImpl

protected RelDataType validateImpl()

Description copied from class: AbstractNamespace

Validates this scope and returns the type of the records it returns. External users should call AbstractNamespace.validate(), which uses the AbstractNamespace.status field to protect against cycles.

Specified by:

validateImpl in class AbstractNamespace

Returns:

record data type, never null

getNode

public SqlNode getNode()

Description copied from interface: SqlValidatorNamespace

Returns the parse tree node at the root of this namespace.

Returns:

parse tree node

translate

public String translate(String name)

Description copied from interface: SqlValidatorNamespace

Translates a field name to the name in the underlying namespace.

Specified by:

translate in interface SqlValidatorNamespace

Overrides:

translate in class AbstractNamespace