org.apache.calcite.sql.validate

Class FieldNamespace

java.lang.Object

org.apache.calcite.sql.validate.AbstractNamespace

org.apache.calcite.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.

Field Summary

Fields inherited from class org.apache.calcite.sql.validate.AbstractNamespace

enclosingNode, rowType, type, validator

Constructor Summary

Constructors

Constructor and Description
FieldNamespace(SqlValidatorImpl validator, RelDataType dataType) Creates a FieldNamespace.

Method Summary

Modifier and Type	Method and Description
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	setType(RelDataType type) Sets the type of this namespace.
protected RelDataType	validateImpl(RelDataType targetRowType) Validates this scope and returns the type of the records it returns.

Methods inherited from class org.apache.calcite.sql.validate.AbstractNamespace

convertToStruct, getEnclosingNode, getMonotonicExprs, getMonotonicity, getRowType, getRowTypeSansSystemColumns, getTable, getType, getValidator, isWrapperFor, makeNullable, resolve, supportsModality, toStruct, 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

setType

public void setType(RelDataType type)

Description copied from interface: SqlValidatorNamespace

Sets the type of this namespace.

Allows the type for the namespace to be explicitly set, but usually is called during SqlValidatorNamespace.validate(RelDataType).

Implicitly also sets the row type. If the type is not a struct, then the row type is the type wrapped as a struct with a single column, otherwise the type and row type are the same.

Specified by:

setType in interface SqlValidatorNamespace

Overrides:

setType in class AbstractNamespace

validateImpl

protected RelDataType validateImpl(RelDataType targetRowType)

Description copied from class: AbstractNamespace

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

Specified by:

validateImpl in class AbstractNamespace

Parameters:

targetRowType - Desired row type, must not be null, may be the data type 'unknown'.

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; null for TableNamespace

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