Package org.apache.calcite.sql.type

Class ExplicitReturnTypeInference

java.lang.Object

org.apache.calcite.sql.type.ExplicitReturnTypeInference

All Implemented Interfaces:

SqlReturnTypeInference

Direct Known Subclasses:

TableFunctionReturnTypeInference

public class ExplicitReturnTypeInference
extends Object
implements SqlReturnTypeInference

A SqlReturnTypeInference which always returns the same SQL type.

Field Summary

Fields

Modifier and Type	Field	Description
protected final RelProtoDataType	protoType

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ExplicitReturnTypeInference(RelProtoDataType protoType)	Creates an inference rule which always returns the same type object.

Method Summary

Modifier and Type	Method	Description
RelDataType	inferReturnType(SqlOperatorBinding opBinding)	Infers the return type of a call to an SqlOperator.

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.type.SqlReturnTypeInference

andThen, orElse

Field Details

protoType

protected final RelProtoDataType protoType

Constructor Details

ExplicitReturnTypeInference

protected ExplicitReturnTypeInference(RelProtoDataType protoType)

Creates an inference rule which always returns the same type object.

If the requesting type factory is different, returns a copy of the type object made using RelDataTypeFactory.copyType(RelDataType) within the requesting type factory.

A copy of the type is required because each statement is prepared using a different type factory; each type factory maintains its own cache of canonical instances of each type.

Parameters:

protoType - Type object

Method Details

inferReturnType

public RelDataType inferReturnType(SqlOperatorBinding opBinding)

Description copied from interface: SqlReturnTypeInference

Infers the return type of a call to an SqlOperator.

Specified by:

inferReturnType in interface SqlReturnTypeInference

Parameters:

opBinding - description of operator binding

Returns:

inferred type; may be null