org.apache.calcite.sql.validate

Class EmptyScope

java.lang.Object

org.apache.calcite.sql.validate.EmptyScope

All Implemented Interfaces:

SqlValidatorScope

Direct Known Subclasses:

ParameterScope

class EmptyScope
extends Object
implements SqlValidatorScope

Deviant implementation of SqlValidatorScope for the top of the scope stack.

It is convenient, because we never need to check whether a scope's parent is null. (This scope knows not to ask about its parents, just like Adam.)

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.calcite.sql.validate.SqlValidatorScope

SqlValidatorScope.EmptyPath, SqlValidatorScope.Path, SqlValidatorScope.Resolve, SqlValidatorScope.Resolved, SqlValidatorScope.ResolvedImpl, SqlValidatorScope.Step

Field Summary

Fields

Modifier and Type	Field and Description
protected SqlValidatorImpl	validator

Constructor Summary

Constructors

Constructor and Description
EmptyScope(SqlValidatorImpl validator)

Method Summary

Modifier and Type	Method and Description
void	addChild(SqlValidatorNamespace ns, String alias, boolean nullable) 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.
void	findAllTableNames(List<SqlMoniker> result)
Pair<String,SqlValidatorNamespace>	findQualifyingTableName(String columnName, SqlNode ctx)
Map<String,ScopeChild>	findQualifyingTableNames(String columnName, SqlNode ctx, SqlNameMatcher nameMatcher) Finds all table aliases which are implicitly qualifying an unqualified column name.
SqlQualified	fullyQualify(SqlIdentifier identifier) Converts an identifier into a fully-qualified identifier.
SqlMonotonicity	getMonotonicity(SqlNode expr) Returns whether an expression is monotonic in this scope.
SqlNode	getNode() Returns the root node of this scope.
SqlValidatorScope	getOperandScope(SqlCall call) Returns the scope within which operands to a call are to be validated.
SqlNodeList	getOrderList() Returns the expressions by which the rows in this scope are sorted.
SqlValidatorNamespace	getTableNamespace(List<String> names)
SqlValidator	getValidator() Returns the validator which created this scope.
SqlWindow	lookupWindow(String name) Finds a window with a given name.
RelDataType	nullifyType(SqlNode node, RelDataType type) Converts the type of an expression to nullable, if the context warrants it.
private void	resolve_(CalciteSchema rootSchema, List<String> names, List<String> schemaNames, SqlNameMatcher nameMatcher, SqlValidatorScope.Path path, SqlValidatorScope.Resolved resolved)
void	resolve(List<String> names, SqlNameMatcher nameMatcher, boolean deep, SqlValidatorScope.Resolved resolved) Looks up a node with a given name.
RelDataType	resolveColumn(String name, SqlNode ctx) Resolves a single identifier to a column, and returns the datatype of that column.
void	resolveTable(List<String> names, SqlNameMatcher nameMatcher, SqlValidatorScope.Path path, SqlValidatorScope.Resolved resolved) Looks up a table in this scope from its name.
void	validateExpr(SqlNode expr) Performs any scope-specific validation of an expression.

Methods inherited from class java.lang.Object

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

Field Detail

validator

protected final SqlValidatorImpl validator

Constructor Detail

EmptyScope

EmptyScope(SqlValidatorImpl validator)

Method Detail

getValidator

public SqlValidator getValidator()

Description copied from interface: SqlValidatorScope

Returns the validator which created this scope.

Specified by:

getValidator in interface SqlValidatorScope

fullyQualify

public SqlQualified fullyQualify(SqlIdentifier identifier)

Description copied from interface: SqlValidatorScope

Converts an identifier into a fully-qualified identifier. For example, the "empno" in "select empno from emp natural join dept" becomes "emp.empno".

Specified by:

fullyQualify in interface SqlValidatorScope

Returns:

A qualified identifier, never null

getNode

public SqlNode getNode()

Description copied from interface: SqlValidatorScope

Returns the root node of this scope. Never null.

Specified by:

getNode in interface SqlValidatorScope

resolve

public void resolve(List<String> names,
                    SqlNameMatcher nameMatcher,
                    boolean deep,
                    SqlValidatorScope.Resolved resolved)

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

Parameters:

names - Name of node to find, maybe partially or fully qualified

nameMatcher - Name matcher

deep - Whether to look more than one level deep

resolved - Callback wherein to write the match(es) we find

getTableNamespace

public SqlValidatorNamespace getTableNamespace(List<String> names)

Specified by:

getTableNamespace in interface SqlValidatorScope

resolveTable

public void resolveTable(List<String> names,
                         SqlNameMatcher nameMatcher,
                         SqlValidatorScope.Path path,
                         SqlValidatorScope.Resolved resolved)

Description copied from interface: SqlValidatorScope

Looks up a table in this scope from its name. If found, calls SqlValidatorScope.resolve(List, SqlNameMatcher, boolean, Resolved). TableNamespace that wraps it. If the "table" is defined in a WITH clause it may be a query, not a table after all.

The name matcher is not null, and one typically uses SqlValidatorCatalogReader.nameMatcher().

Specified by:

resolveTable in interface SqlValidatorScope

Parameters:

names - Name of table, may be qualified or fully-qualified

nameMatcher - Name matcher

path - List of names that we have traversed through so far

resolve_

private void resolve_(CalciteSchema rootSchema,
                      List<String> names,
                      List<String> schemaNames,
                      SqlNameMatcher nameMatcher,
                      SqlValidatorScope.Path path,
                      SqlValidatorScope.Resolved resolved)

nullifyType

public RelDataType nullifyType(SqlNode node,
                               RelDataType type)

Description copied from interface: SqlValidatorScope

Converts the type of an expression to nullable, if the context warrants it.

Specified by:

nullifyType in interface SqlValidatorScope

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

Parameters:

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

findAllTableNames

public void findAllTableNames(List<SqlMoniker> result)

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

Parameters:

result - a list of monikers to add the result to

resolveColumn

public RelDataType resolveColumn(String name,
                                 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

Parameters:

name - Name of column

ctx - Context for exception

Returns:

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

getOperandScope

public SqlValidatorScope getOperandScope(SqlCall call)

Description copied from interface: SqlValidatorScope

Returns the scope within which operands to a call are to be validated. Usually it is this scope, but when the call is to an aggregate function and this is an aggregating scope, it will be a a different scope.

Specified by:

getOperandScope in interface SqlValidatorScope

Parameters:

call - Call

Returns:

Scope within which to validate arguments to call.

validateExpr

public void validateExpr(SqlNode expr)

Description copied from interface: SqlValidatorScope

Performs any scope-specific validation of an expression. For example, an aggregating scope requires that expressions are valid aggregations. The expression has already been validated.

Specified by:

validateExpr in interface SqlValidatorScope

findQualifyingTableName

public Pair<String,SqlValidatorNamespace> findQualifyingTableName(String columnName,
                                                                  SqlNode ctx)

Specified by:

findQualifyingTableName in interface SqlValidatorScope

findQualifyingTableNames

public Map<String,ScopeChild> findQualifyingTableNames(String columnName,
                                                       SqlNode ctx,
                                                       SqlNameMatcher nameMatcher)

Description copied from interface: SqlValidatorScope

Finds all table aliases which are implicitly qualifying an unqualified column name.

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:

findQualifyingTableNames in interface SqlValidatorScope

Parameters:

columnName - Column name

ctx - Validation context, to appear in any error thrown

nameMatcher - Name matcher

Returns:

Map of applicable table alias and namespaces, never null, empty if no aliases found

addChild

public void addChild(SqlValidatorNamespace ns,
                     String alias,
                     boolean nullable)

Description copied from interface: SqlValidatorScope

Registers a relation in this scope.

Specified by:

addChild in interface SqlValidatorScope

Parameters:

ns - Namespace representing the result-columns of the relation

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

nullable - Whether this is a null-generating side of a join

lookupWindow

public SqlWindow lookupWindow(String name)

Description copied from interface: SqlValidatorScope

Finds a window with a given name. Returns null if not found.

Specified by:

lookupWindow in interface SqlValidatorScope

getMonotonicity

public SqlMonotonicity getMonotonicity(SqlNode expr)

Description copied from interface: SqlValidatorScope

Returns whether an expression is monotonic in this scope. For example, if the scope has previously been sorted by columns X, Y, then X is monotonic in this scope, but Y is not.

Specified by:

getMonotonicity in interface SqlValidatorScope

getOrderList

public SqlNodeList getOrderList()

Description copied from interface: SqlValidatorScope

Returns the expressions by which the rows in this scope are sorted. If the rows are unsorted, returns null.

Specified by:

getOrderList in interface SqlValidatorScope