org.eigenbase.sql.validate
Class ListScope

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

All Implemented Interfaces:

SqlValidatorScope

Direct Known Subclasses:

CollectScope, JoinScope, OverScope, SelectScope

public abstract class ListScope
extends DelegatingScope

Abstract base for a scope which is defined by a list of child namespaces and which inherits from a parent scope.

Since:

Mar 25, 2003

Version:

$Id: //open/dev/farrago/src/org/eigenbase/sql/validate/ListScope.java#13 $

Author:

jhyde

Field Summary

protected List<SqlValidatorNamespace>	children List of child SqlValidatorNamespace objects.
protected List<String>	childrenNames Aliases of the SqlValidatorNamespace objects.

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

parent, validator

Constructor Summary

ListScope(SqlValidatorScope parent)

Method Summary

void	addChild(SqlValidatorNamespace ns, String alias) Registers a relation in this scope.
void	findAliases(List<SqlMoniker> result) Collects the SqlMonikers of all table aliases (uses of tables in query FROM clauses) available in this scope.
void	findAllColumnNames(List<SqlMoniker> result) Collects the SqlMonikers of all possible columns in this scope.
String	findQualifyingTableName(String columnName, SqlNode ctx) Finds the table alias which is implicitly qualifying an unqualified column name.
protected SqlValidatorNamespace	getChild(String alias)
List<SqlValidatorNamespace>	getChildren() Returns an immutable list of child namespaces.
SqlValidatorNamespace	resolve(String name, SqlValidatorScope[] ancestorOut, int[] offsetOut) Looks up a node with a given name.
RelDataType	resolveColumn(String columnName, SqlNode ctx) Resolves a single identifier to a column, and returns the datatype of that column.

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

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eigenbase.sql.validate.SqlValidatorScope

getNode

Field Detail

children

protected final List<SqlValidatorNamespace> children

List of child SqlValidatorNamespace objects.

childrenNames

protected final List<String> childrenNames

Aliases of the SqlValidatorNamespace objects.

Constructor Detail

ListScope

public ListScope(SqlValidatorScope parent)

Method Detail

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 DelegatingScope

Parameters:

ns - Namespace representing the result-columns of the relation

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

getChildren

public List<SqlValidatorNamespace> getChildren()

Returns an immutable list of child namespaces.

Returns:

list of child namespaces

getChild

protected SqlValidatorNamespace getChild(String alias)

findAllColumnNames

public void findAllColumnNames(List<SqlMoniker> result)

Description copied from interface: SqlValidatorScope

Collects the SqlMonikers of all possible columns in this scope.

Specified by:

findAllColumnNames in interface SqlValidatorScope

Overrides:

findAllColumnNames in class DelegatingScope

Parameters:

result - an array list of strings to add the result to

findAliases

public void findAliases(List<SqlMoniker> result)

Description copied from interface: SqlValidatorScope

Collects the SqlMonikers of all table aliases (uses of tables in query FROM clauses) available in this scope.

Specified by:

findAliases in interface SqlValidatorScope

Overrides:

findAliases in class DelegatingScope

Parameters:

result - a list of monikers to add the result to

findQualifyingTableName

public String findQualifyingTableName(String columnName,
                                      SqlNode ctx)

Description copied from interface: SqlValidatorScope

Finds the table alias which is implicitly qualifying an unqualified column name. Throws an error if there is not exactly one table.

This method is only implemented in scopes (such as SelectScope) which can be the context for name-resolution. In scopes such as IdentifierNamespace, it throws UnsupportedOperationException.

Specified by:

findQualifyingTableName in interface SqlValidatorScope

Overrides:

findQualifyingTableName in class DelegatingScope

Parameters:

columnName - Column name

ctx - Validation context, to appear in any error thrown

Returns:

Table alias

resolve

public SqlValidatorNamespace resolve(String name,
                                     SqlValidatorScope[] ancestorOut,
                                     int[] offsetOut)

Description copied from interface: SqlValidatorScope

Looks up a node with a given name. Returns null if none is found.

Specified by:

resolve in interface SqlValidatorScope

Overrides:

resolve in class DelegatingScope

Parameters:

name - Name of node to find

ancestorOut - If not null, writes the ancestor scope here

offsetOut - If not null, writes the offset within the ancestor here

resolveColumn

public RelDataType resolveColumn(String columnName,
                                 SqlNode ctx)

Description copied from interface: SqlValidatorScope

Resolves a single identifier to a column, and returns the datatype of that column.

If it cannot find the column, returns null. If the column is ambiguous, throws an error with context ctx.

Specified by:

resolveColumn in interface SqlValidatorScope

Overrides:

resolveColumn in class DelegatingScope

Parameters:

columnName - Name of column

ctx - Context for exception

Returns:

Type of column, if found and unambiguous; null if not found