org.apache.calcite.sql.validate

Class AggregatingSelectScope

java.lang.Object

org.apache.calcite.sql.validate.DelegatingScope

org.apache.calcite.sql.validate.AggregatingSelectScope

All Implemented Interfaces:

AggregatingScope, SqlValidatorScope

public class AggregatingSelectScope
extends DelegatingScope
implements AggregatingScope

Scope for resolving identifiers within a SELECT statement that has a GROUP BY clause.

The same set of identifiers are in scope, but it won't allow access to identifiers or expressions which are not group-expressions.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AggregatingSelectScope.Resolved Information about an aggregating scope that can only be determined after validation has occurred.

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

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

Field Summary

Fields

Modifier and Type	Field and Description
Supplier<AggregatingSelectScope.Resolved>	resolved

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

parent, validator

Method Summary

Modifier and Type	Method and Description
boolean	checkAggregateExpr(SqlNode expr, boolean deep) Checks whether an expression is constant within the GROUP BY clause.
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.
RelDataType	nullifyType(SqlNode node, RelDataType type) Converts the type of an expression to nullable, if the context warrants it.
void	validateExpr(SqlNode expr) Performs any scope-specific validation of an expression.

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

addChild, addColumnNames, findAliases, findAllColumnNames, findQualifyingTableName, findQualifyingTableNames, fullyQualify, getMonotonicity, getOrderList, getParent, getTableNamespace, getValidator, lookupWindow, resolve, resolveColumn, resolveTable

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

addChild, findAliases, findAllColumnNames, findQualifyingTableName, findQualifyingTableNames, fullyQualify, getMonotonicity, getOrderList, getTableNamespace, getValidator, isWithin, lookupWindow, resolve, resolveColumn, resolveTable

Field Detail

resolved

public final Supplier<AggregatingSelectScope.Resolved> resolved

Method Detail

getNode

public SqlNode getNode()

Description copied from interface: SqlValidatorScope

Returns the root node of this scope. Never null.

Specified by:

getNode in interface SqlValidatorScope

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

Overrides:

nullifyType in class DelegatingScope

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

Overrides:

getOperandScope in class DelegatingScope

Parameters:

call - Call

Returns:

Scope within which to validate arguments to call.

checkAggregateExpr

public boolean checkAggregateExpr(SqlNode expr,
                                  boolean deep)

Description copied from interface: AggregatingScope

Checks whether an expression is constant within the GROUP BY clause. If the expression completely matches an expression in the GROUP BY clause, returns true. If the expression is constant within the group, but does not exactly match, returns false. If the expression is not constant, throws an exception. Examples:

• If we are 'f(b, c)' in 'SELECT a + f(b, c) FROM t GROUP BY a', then the whole expression matches a group column. Return true.
• Just an ordinary expression in a GROUP BY query, such as 'f(SUM(a), 1, b)' in 'SELECT f(SUM(a), 1, b) FROM t GROUP BY b'. Returns false.
• Illegal expression, such as 'f(5, a, b)' in 'SELECT f(a, b) FROM t GROUP BY a'. Throws when it enounters the 'b' operand, because it is not in the group clause.

Specified by:

checkAggregateExpr in interface AggregatingScope

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

Overrides:

validateExpr in class DelegatingScope