Package org.apache.calcite.sql.validate

Class MeasureScope

java.lang.Object

org.apache.calcite.sql.validate.DelegatingScope

org.apache.calcite.sql.validate.MeasureScope

All Implemented Interfaces:

SqlValidatorScope

public class MeasureScope
extends DelegatingScope

Scope for resolving identifiers within a SELECT item that is annotated "AS MEASURE".

Scope includes the identifiers of SELECT plus all aliases. This allows measures to reference each other and also reference other SELECT items.

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

parent, resolved, validator

Method Summary

Modifier and Type	Method	Description
SqlQualified	fullyQualify(SqlIdentifier identifier)	Converts an identifier into a fully-qualified identifier.
SqlNode	getNode()	Returns the root node of this scope.
@Nullable SqlNode	lookupMeasure(String name)
@Nullable RelDataType	resolveColumn(String name, SqlNode ctx)	Resolves a single identifier to a column, and returns the datatype of that column.
void	validateExpr(SqlNode expr)	Performs any scope-specific validation of an expression.

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

addChild, addColumnNames, analyze, findAliases, findAllColumnNames, findQualifyingTableName, findQualifyingTableNames, getMonotonicity, getOperandScope, getOrderList, getParent, getTableNamespace, getValidator, lookupWindow, nullifyType, qualifyUsingAlias, resolve, 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

isMeasureRef, isWithin

Method Details

getNode

public SqlNode getNode()

Description copied from interface: SqlValidatorScope

Returns the root node of this scope. Never null.

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

resolveColumn

public @Nullable 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

Overrides:

resolveColumn in class DelegatingScope

Parameters:

name - Name of column

ctx - Context for exception

Returns:

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

lookupMeasure

public @Nullable SqlNode lookupMeasure(String name)

fullyQualify

public SqlQualified fullyQualify(SqlIdentifier identifier)

Description copied from class: DelegatingScope

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

If the identifier cannot be resolved, throws. Never returns null.

Specified by:

fullyQualify in interface SqlValidatorScope

Overrides:

fullyQualify in class DelegatingScope

Returns:

A qualified identifier, never null