com.orientechnologies.lucene.functions

Class OLuceneSearchMoreLikeThisFunction

java.lang.Object

com.orientechnologies.orient.core.sql.functions.OSQLFunctionAbstract

com.orientechnologies.lucene.functions.OLuceneSearchMoreLikeThisFunction

All Implemented Interfaces:

OIndexableSQLFunction, OSQLFunction

public class OLuceneSearchMoreLikeThisFunction
extends OSQLFunctionAbstract
implements OIndexableSQLFunction

Created by frank on 15/01/2017.

Field Summary

Fields

Modifier and Type	Field and Description
static String	NAME

Fields inherited from class com.orientechnologies.orient.core.sql.functions.OSQLFunctionAbstract

maxParams, minParams, name

Constructor Summary

Constructors

Constructor and Description
OLuceneSearchMoreLikeThisFunction()

Method Summary

Modifier and Type	Method and Description
boolean	allowsIndexedExecution(OFromClause target, OBinaryCompareOperator operator, Object rightValue, OCommandContext ctx, OExpression... args) Checks if this function can be used to fetch data from this target and with these arguments (eg.
boolean	canExecuteInline(OFromClause target, OBinaryCompareOperator operator, Object rightValue, OCommandContext ctx, OExpression... args) checks if the function can be used even on single records, not as an indexed function (even if the index does not exist at all)
long	estimate(OFromClause target, OBinaryCompareOperator operator, Object rightValue, OCommandContext ctx, OExpression... args) estimates the number of entries returned by searchFromTarget() with these parameters
Object	execute(Object iThis, OIdentifiable iCurrentRecord, Object iCurrentResult, Object[] params, OCommandContext ctx) Process a record.
String	getName() Function name, the name is used by the sql parser to identify a call this function.
String	getSyntax() Returns a convenient SQL String representation of the function.
Iterable<OIdentifiable>	searchFromTarget(OFromClause target, OBinaryCompareOperator operator, Object rightValue, OCommandContext ctx, OExpression... args) returns all the entries belonging to the target that match the binary condition where this function appears
boolean	shouldExecuteAfterSearch(OFromClause target, OBinaryCompareOperator operator, Object rightValue, OCommandContext ctx, OExpression... args) Checks if this function should be called even if the method OIndexableSQLFunction.searchFromTarget(com.orientechnologies.orient.core.sql.parser.OFromClause, com.orientechnologies.orient.core.sql.parser.OBinaryCompareOperator, java.lang.Object, com.orientechnologies.orient.core.command.OCommandContext, com.orientechnologies.orient.core.sql.parser.OExpression...) is executed.

Methods inherited from class com.orientechnologies.orient.core.sql.functions.OSQLFunctionAbstract

aggregateResults, config, filterResult, getDistributedStorageId, getMaxParams, getMinParams, getResult, getSingleItem, getSingleProperty, mergeDistributedResult, returnDistributedResult, setResult, shouldMergeDistributedResult, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.orientechnologies.orient.core.sql.functions.OSQLFunction

aggregateResults, config, filterResult, getMaxParams, getMinParams, getResult, mergeDistributedResult, setResult, shouldMergeDistributedResult

Field Detail

NAME

public static final String NAME

See Also:

Constant Field Values

Constructor Detail

OLuceneSearchMoreLikeThisFunction

public OLuceneSearchMoreLikeThisFunction()

Method Detail

getName

public String getName()

Description copied from interface: OSQLFunction

Function name, the name is used by the sql parser to identify a call this function.

Specified by:

getName in interface OSQLFunction

Overrides:

getName in class OSQLFunctionAbstract

Returns:

String , function name, never null or empty.

execute

public Object execute(Object iThis,
                      OIdentifiable iCurrentRecord,
                      Object iCurrentResult,
                      Object[] params,
                      OCommandContext ctx)

Description copied from interface: OSQLFunction

Process a record.

Specified by:

execute in interface OSQLFunction

iCurrentRecord - : current record

iCurrentResult - TODO

params - : function parameters, number is ensured to be within minParams and maxParams.

ctx - : object calling this function

Returns:

function result, can be null. Special cases : can be null if function aggregate results, can be null if function filter results : this mean result is excluded

getSyntax

public String getSyntax()

Description copied from interface: OSQLFunction

Returns a convenient SQL String representation of the function.

Example :

  myFunction( param1, param2, [optionalParam3])
 

This text will be used in exception messages.

Specified by:

getSyntax in interface OSQLFunction

Returns:

String , never null.

searchFromTarget

public Iterable<OIdentifiable> searchFromTarget(OFromClause target,
                                                OBinaryCompareOperator operator,
                                                Object rightValue,
                                                OCommandContext ctx,
                                                OExpression... args)

Description copied from interface: OIndexableSQLFunction

returns all the entries belonging to the target that match the binary condition where this function appears

Specified by:

searchFromTarget in interface OIndexableSQLFunction

Parameters:

target - the query target

operator - the operator after the function, eg. in select from Foo where myFunction(name) > 4 the operator is >

rightValue - the value that has to be compared to the function result, eg. in select from Foo where myFunction(name) > 4 the right value is 4

ctx - the command context for this query

args - the function arguments, eg. in select from Foo where myFunction(name) > 4 the arguments are [name]

Returns:

an iterable of records that match the condition; null means that the execution could not be performed for some reason.

estimate

public long estimate(OFromClause target,
                     OBinaryCompareOperator operator,
                     Object rightValue,
                     OCommandContext ctx,
                     OExpression... args)

Description copied from interface: OIndexableSQLFunction

estimates the number of entries returned by searchFromTarget() with these parameters

Specified by:

estimate in interface OIndexableSQLFunction

Parameters:

target - the query target

operator - the operator after the function, eg. in select from Foo where myFunction(name) > 4 the operator is >

rightValue - the value that has to be compared to the function result, eg. in select from Foo where myFunction(name) > 4 the right value is 4

ctx - the command context for this query

args - the function arguments, eg. in select from Foo where myFunction(name) > 4 the arguments are [name]

Returns:

an estimantion of how many entries will be returned by searchFromTarget() with these parameters, -1 if the estimation cannot be done

canExecuteInline

public boolean canExecuteInline(OFromClause target,
                                OBinaryCompareOperator operator,
                                Object rightValue,
                                OCommandContext ctx,
                                OExpression... args)

Description copied from interface: OIndexableSQLFunction

checks if the function can be used even on single records, not as an indexed function (even if the index does not exist at all)

Specified by:

canExecuteInline in interface OIndexableSQLFunction

Parameters:

target - the query target

operator - the operator after the function, eg. in select from Foo where myFunction(name) > 4 the operator is >

rightValue - the value that has to be compared to the function result, eg. in select from Foo where myFunction(name) > 4 the right value is 4

ctx - the command context for this query

args - the function arguments, eg. in select from Foo where myFunction(name) > 4 the arguments are [name]

Returns:

true if the funciton can be calculated without the index. False otherwise

allowsIndexedExecution

public boolean allowsIndexedExecution(OFromClause target,
                                      OBinaryCompareOperator operator,
                                      Object rightValue,
                                      OCommandContext ctx,
                                      OExpression... args)

Description copied from interface: OIndexableSQLFunction

Checks if this function can be used to fetch data from this target and with these arguments (eg. if the index exists on this target and it's defined on these fields)

Specified by:

allowsIndexedExecution in interface OIndexableSQLFunction

Parameters:

target - the query target

operator - the operator after the function, eg. in select from Foo where myFunction(name) > 4 the operator is >

rightValue - the value that has to be compared to the function result, eg. in select from Foo where myFunction(name) > 4 the right value is 4

ctx - the command context for this query

args - the function arguments, eg. in select from Foo where myFunction(name) > 4 the arguments are [name]

Returns:

True if the funciton can be used to fetch from an index. False otherwise

shouldExecuteAfterSearch

public boolean shouldExecuteAfterSearch(OFromClause target,
                                        OBinaryCompareOperator operator,
                                        Object rightValue,
                                        OCommandContext ctx,
                                        OExpression... args)

Description copied from interface: OIndexableSQLFunction

Checks if this function should be called even if the method OIndexableSQLFunction.searchFromTarget(com.orientechnologies.orient.core.sql.parser.OFromClause, com.orientechnologies.orient.core.sql.parser.OBinaryCompareOperator, java.lang.Object, com.orientechnologies.orient.core.command.OCommandContext, com.orientechnologies.orient.core.sql.parser.OExpression...) is executed.

Specified by:

shouldExecuteAfterSearch in interface OIndexableSQLFunction

Parameters:

target - the query target

operator - the operator after the function, eg. in select from Foo where myFunction(name) > 4 the operator is >

rightValue - the value that has to be compared to the function result, eg. in select from Foo where myFunction(name) > 4 the right value is 4

ctx - the command context for this query

args - the function arguments, eg. in select from Foo where myFunction(name) > 4 the arguments are [name]

Returns:

True if this function should be called even if the method OIndexableSQLFunction.searchFromTarget(com.orientechnologies.orient.core.sql.parser.OFromClause, com.orientechnologies.orient.core.sql.parser.OBinaryCompareOperator, java.lang.Object, com.orientechnologies.orient.core.command.OCommandContext, com.orientechnologies.orient.core.sql.parser.OExpression...) is executed. False otherwise