com.orientechnologies.orient.core.sql.functions.misc

Class OSQLFunctionIfNull

java.lang.Object

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

com.orientechnologies.orient.core.sql.functions.misc.OSQLFunctionIfNull

All Implemented Interfaces:

OSQLFunction

public class OSQLFunctionIfNull
extends OSQLFunctionAbstract

Returns the passed field/value (or optional parameter return_value_if_not_null ) if field/value is not null; otherwise it returns return_value_if_null.

Syntax:

 ifnull(<field|value>, <return_value_if_null> [,<return_value_if_not_null>])
 

Examples:

 SELECT ifnull('a', 'b') FROM ...
  -> 'a'

 SELECT ifnull('a', 'b', 'c') FROM ...
  -> 'c'

 SELECT ifnull(null, 'b') FROM ...
  -> 'b'

 SELECT ifnull(null, 'b', 'c') FROM ...
  -> 'b'
 

Author:

Mark Bigler

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
OSQLFunctionIfNull()

Method Summary

Modifier and Type	Method and Description
Object	execute(Object iThis, OIdentifiable iCurrentRecord, Object iCurrentResult, Object[] iParams, OCommandContext iContext) Process a record.
String	getSyntax() Returns a convenient SQL String representation of the function.

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

aggregateResults, config, filterResult, getDistributedStorageId, getMaxParams, getMinParams, getName, 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

Field Detail

NAME

public static final String NAME

See Also:

Constant Field Values

Constructor Detail

OSQLFunctionIfNull

public OSQLFunctionIfNull()

Method Detail

execute

public Object execute(Object iThis,
                      OIdentifiable iCurrentRecord,
                      Object iCurrentResult,
                      Object[] iParams,
                      OCommandContext iContext)

Description copied from interface: OSQLFunction

Process a record.

iCurrentRecord - : current record

iCurrentResult - TODO

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

iContext - : 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.

Returns:

String , never null.