Package org.apache.calcite.adapter.enumerable

Enum JavaRowFormat

java.lang.Object

java.lang.Enum<JavaRowFormat>

org.apache.calcite.adapter.enumerable.JavaRowFormat

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<JavaRowFormat>

public enum JavaRowFormat
extends java.lang.Enum<JavaRowFormat>

How a row is represented as a Java value.

Enum Constant Summary

Enum Constants

Enum Constant	Description
ARRAY
CUSTOM
LIST	A list that is comparable and immutable.
ROW	See Row
SCALAR

Constructor Summary

Constructors

Modifier	Constructor	Description
private	JavaRowFormat()

Method Summary

Modifier and Type	Method	Description
Expression	comparer()
abstract Expression	field(Expression expression, int field, java.lang.reflect.Type fromType, java.lang.reflect.Type fieldType)	Returns a reference to a particular field.
(package private) abstract java.lang.reflect.Type	javaFieldClass(JavaTypeFactory typeFactory, RelDataType type, int index)	Returns the java class that is used to physically store the given field.
(package private) abstract java.lang.reflect.Type	javaRowClass(JavaTypeFactory typeFactory, RelDataType type)
JavaRowFormat	optimize(RelDataType rowType)
abstract Expression	record(java.lang.reflect.Type javaRowClass, java.util.List<Expression> expressions)
static JavaRowFormat	valueOf(java.lang.String name)	Returns the enum constant of this type with the specified name.
static JavaRowFormat[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

CUSTOM

public static final JavaRowFormat CUSTOM

SCALAR

public static final JavaRowFormat SCALAR

LIST

public static final JavaRowFormat LIST

A list that is comparable and immutable. Useful for records with 0 fields (empty list is a good singleton) but sometimes also for records with 2 or more fields that you need to be comparable, say as a key in a lookup.

ROW

public static final JavaRowFormat ROW

See Row

ARRAY

public static final JavaRowFormat ARRAY

Constructor Detail

JavaRowFormat

private JavaRowFormat()

Method Detail

values

public static JavaRowFormat[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (JavaRowFormat c : JavaRowFormat.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static JavaRowFormat valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null

optimize

public JavaRowFormat optimize(RelDataType rowType)

javaRowClass

abstract java.lang.reflect.Type javaRowClass(JavaTypeFactory typeFactory,
                                             RelDataType type)

javaFieldClass

abstract java.lang.reflect.Type javaFieldClass(JavaTypeFactory typeFactory,
                                               RelDataType type,
                                               int index)

Returns the java class that is used to physically store the given field. For instance, a non-null int field can still be stored in a field of type Object.class in ARRAY case.

Parameters:

typeFactory - type factory to resolve java types

type - row type

index - field index

Returns:

java type used to store the field

record

public abstract Expression record(java.lang.reflect.Type javaRowClass,
                                  java.util.List<Expression> expressions)

comparer

public Expression comparer()

field

public abstract Expression field(Expression expression,
                                 int field,
                                 java.lang.reflect.Type fromType,
                                 java.lang.reflect.Type fieldType)

Returns a reference to a particular field.

fromType may be null; if null, uses the natural type of the field.