org.apache.calcite.sql.validate

Class ListScope

java.lang.Object

org.apache.calcite.sql.validate.DelegatingScope

org.apache.calcite.sql.validate.ListScope

All Implemented Interfaces:

SqlValidatorScope

Direct Known Subclasses:

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.

Field Summary

Fields

Modifier and Type	Field and Description
protected List<Pair<String,SqlValidatorNamespace>>	children List of child SqlValidatorNamespace objects and their names.

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

parent, validator

Constructor Summary

Constructors

Constructor and Description
ListScope(SqlValidatorScope parent)

Method Summary

Methods

Modifier and Type	Method and Description
void	addChild(SqlValidatorNamespace ns, String alias) Registers a relation in this scope.
void	findAliases(Collection<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.
protected int	findChild(List<String> names)
Pair<String,SqlValidatorNamespace>	findQualifyingTableName(String columnName, SqlNode ctx) Finds the table alias which is implicitly qualifying an unqualified column name.
protected SqlValidatorNamespace	getChild(List<String> names) Returns a child namespace that matches a fully-qualified list of names.
protected SqlValidatorNamespace	getChild(String alias)
List<SqlValidatorNamespace>	getChildren() Returns an immutable list of child namespaces.
SqlValidatorNamespace	resolve(List<String> names, 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.apache.calcite.sql.validate.DelegatingScope

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.calcite.sql.validate.SqlValidatorScope

getNode

Field Detail

children

protected final List<Pair<String,SqlValidatorNamespace>> children

List of child SqlValidatorNamespace objects and their names.

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)

getChild

protected SqlValidatorNamespace getChild(List<String> names)

Returns a child namespace that matches a fully-qualified list of names. This will be a schema-qualified table, for example

SELECT sales.emp.empno FROM sales.emp

findChild

protected int findChild(List<String> names)

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(Collection<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 Pair<String,SqlValidatorNamespace> 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 and namespace

resolve

public SqlValidatorNamespace resolve(List<String> names,
                            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:

names - 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