org.eigenbase.sql.validate
Class FieldNamespace

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

All Implemented Interfaces:

SqlValidatorNamespace

 class FieldNamespace
extends AbstractNamespace

Implementation of SqlValidatorNamespace for a field of a record.

A field is not a very interesting namespace - except if the field has a record or multiset type - but this class exists to make fields behave similarly to other records for purposes of name resolution.

Version:

$Id: //open/dev/farrago/src/org/eigenbase/sql/validate/FieldNamespace.java#5 $

Author:

jhyde

Field Summary

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

enclosingNode, rowType, validator

Constructor Summary

FieldNamespace(SqlValidatorImpl validator, RelDataType dataType)
Creates a FieldNamespace.

Method Summary

boolean	fieldExists(String name) Returns whether this namespace has a field of a given name.
SqlNode	getNode() Returns the parse tree node at the root of this namespace.
SqlValidatorNamespace	lookupChild(String name) Looks up a child namespace of a given name.
void	setRowType(RelDataType rowType) Allows RowType for the namespace to be explicitly set.
protected RelDataType	validateImpl() Validates this scope and returns the type of the records it returns.

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

getEnclosingNode, getMonotonicExprs, getMonotonicity, getRowType, getRowTypeSansSystemColumns, getTable, getValidator, isWrapperFor, makeNullable, translate, unwrap, validate

Methods inherited from class java.lang.Object

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

Constructor Detail

FieldNamespace

FieldNamespace(SqlValidatorImpl validator,
               RelDataType dataType)

Creates a FieldNamespace.

Parameters:

validator - Validator

dataType - Data type of field

Method Detail

setRowType

public void setRowType(RelDataType rowType)

Description copied from interface: SqlValidatorNamespace

Allows RowType for the namespace to be explicitly set.

Specified by:

setRowType in interface SqlValidatorNamespace

Overrides:

setRowType in class AbstractNamespace

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

lookupChild

public SqlValidatorNamespace lookupChild(String name)

Description copied from interface: SqlValidatorNamespace

Looks up a child namespace of a given name.

For example, in the query select e.name from emps as e, e is an IdentifierNamespace which has a child name which is a FieldNamespace.

Specified by:

lookupChild in interface SqlValidatorNamespace

Overrides:

lookupChild in class AbstractNamespace

Parameters:

name - Name of namespace

Returns:

Namespace

fieldExists

public boolean fieldExists(String name)

Description copied from interface: SqlValidatorNamespace

Returns whether this namespace has a field of a given name.

Specified by:

fieldExists in interface SqlValidatorNamespace

Overrides:

fieldExists in class AbstractNamespace

Parameters:

name - Field name

Returns:

Whether field exists