org.apache.phoenix.expression

Class StringConcatExpression

java.lang.Object

org.apache.phoenix.expression.BaseExpression

org.apache.phoenix.expression.BaseCompoundExpression

org.apache.phoenix.expression.StringConcatExpression

All Implemented Interfaces:

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

public class StringConcatExpression
extends BaseCompoundExpression

Implementation for || string concatenation expression.

Since:

0.1

Nested Class Summary

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

BaseExpression.ExpressionComparabilityWrapper

Field Summary

Fields inherited from class org.apache.phoenix.expression.BaseCompoundExpression

children

Constructor Summary

Constructors

Constructor and Description
StringConcatExpression()
StringConcatExpression(List<Expression> children)

Method Summary

Modifier and Type	Method and Description
<T> T	accept(ExpressionVisitor<T> visitor) Means of traversing expression tree through visitor.
boolean	evaluate(Tuple tuple, ImmutableBytesWritable ptr) Access the value by setting a pointer to it (as opposed to making a copy of it which can be expensive)
PDataType	getDataType()
boolean	requiresFinalEvaluation() Determines if an evaluate is required after partial evaluation is run.
String	toString()

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

equals, getChildren, getDeterminism, hashCode, isNullable, isStateless, readFields, reset, write

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

acceptChildren, coerce, coerce, getMaxLength, getScale, getSortOrder

Methods inherited from class java.lang.Object

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

Constructor Detail

StringConcatExpression

public StringConcatExpression()

StringConcatExpression

public StringConcatExpression(List<Expression> children)

Method Detail

toString

public String toString()

Overrides:

toString in class BaseCompoundExpression

accept

public final <T> T accept(ExpressionVisitor<T> visitor)

Description copied from interface: Expression

Means of traversing expression tree through visitor.

requiresFinalEvaluation

public boolean requiresFinalEvaluation()

Description copied from interface: Expression

Determines if an evaluate is required after partial evaluation is run. For example, in the case of an IS NULL expression, we only know we can return TRUE after all KeyValues have been seen while an expression is used in the context of a filter.

Specified by:

requiresFinalEvaluation in interface Expression

Overrides:

requiresFinalEvaluation in class BaseCompoundExpression

Returns:

evaluate

public boolean evaluate(Tuple tuple,
                        ImmutableBytesWritable ptr)

Description copied from interface: Expression

Access the value by setting a pointer to it (as opposed to making a copy of it which can be expensive)

Parameters:

tuple - Single row result during scan iteration

ptr - Pointer to byte value being accessed

Returns:

true if the expression could be evaluated (i.e. ptr was set) and false otherwise

getDataType

public PDataType getDataType()

Returns:

data type of the column