org.apache.phoenix.expression

Class ColumnExpression

java.lang.Object

org.apache.phoenix.expression.BaseExpression

org.apache.phoenix.expression.BaseTerminalExpression

org.apache.phoenix.expression.ColumnExpression

All Implemented Interfaces:

org.apache.hadoop.io.Writable, Expression, PDatum

Direct Known Subclasses:

KeyValueColumnExpression, ProjectedColumnExpression, RowKeyColumnExpression

public abstract class ColumnExpression
extends BaseTerminalExpression

Common base class for column value accessors

Since:

0.1

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.phoenix.expression.BaseExpression

BaseExpression.ExpressionComparabilityWrapper

Field Summary

Fields

Modifier and Type	Field and Description
protected PDataType	type

Constructor Summary

Constructors

Constructor and Description
ColumnExpression()
ColumnExpression(PDatum datum)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object obj)
PDataType	getDataType()
Integer	getMaxLength()
Integer	getScale()
SortOrder	getSortOrder()
int	hashCode()
boolean	isNullable()
void	readFields(DataInput input)
void	write(DataOutput output)

Methods inherited from class org.apache.phoenix.expression.BaseTerminalExpression

getChildren

Methods inherited from class org.apache.phoenix.expression.BaseExpression

acceptChildren, coerce, coerce, getDeterminism, isStateless, requiresFinalEvaluation, reset

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.phoenix.expression.Expression

accept, evaluate

Field Detail

type

protected PDataType type

Constructor Detail

ColumnExpression

public ColumnExpression()

ColumnExpression

public ColumnExpression(PDatum datum)

Method Detail

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

isNullable

public boolean isNullable()

Specified by:

isNullable in interface PDatum

Overrides:

isNullable in class BaseExpression

Returns:

is this column nullable?

getDataType

public PDataType getDataType()

Returns:

data type of the column

getSortOrder

public SortOrder getSortOrder()

Specified by:

getSortOrder in interface PDatum

Overrides:

getSortOrder in class BaseExpression

Returns:

The SortOrder for this column, never null

getMaxLength

public Integer getMaxLength()

Specified by:

getMaxLength in interface PDatum

Overrides:

getMaxLength in class BaseExpression

Returns:

the actual length of the column. For decimal, it would be its precision. For char or varchar, it would be the maximum length as specified during schema definition.

getScale

public Integer getScale()

Specified by:

getScale in interface PDatum

Overrides:

getScale in class BaseExpression

Returns:

scale of a decimal number.

readFields

public void readFields(DataInput input)
                throws IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Overrides:

readFields in class BaseExpression

Throws:

IOException

write

public void write(DataOutput output)
           throws IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Overrides:

write in class BaseExpression

Throws:

IOException