Package org.datanucleus.store.rdbms.sql.method

Class ArrayIsEmptyMethod

java.lang.Object

org.datanucleus.store.rdbms.sql.method.ArrayIsEmptyMethod

All Implemented Interfaces:

SQLMethod

public class ArrayIsEmptyMethod
extends Object
implements SQLMethod

Method for evaluating {arrExpr1}.isEmpty(). Returns a BooleanExpression, utilising the size() expression. So the SQL will be something like

 (SELECT COUNT(*) FROM ARRTABLE A0_SUB WHERE A0_SUB.OWNER_ID_OID = A0.OWNER_ID) = 0
 

Constructor Summary

Constructors

Constructor	Description
ArrayIsEmptyMethod()

Method Summary

Modifier and Type	Method	Description
SQLExpression	getExpression(SQLStatement stmt, SQLExpression expr, List<SQLExpression> args)	Return the expression for this SQL function.

Methods inherited from class java.lang.Object

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

Constructor Details

ArrayIsEmptyMethod

public ArrayIsEmptyMethod()

Method Details

getExpression

public SQLExpression getExpression(SQLStatement stmt,
 SQLExpression expr,
 List<SQLExpression> args)

Description copied from interface: SQLMethod

Return the expression for this SQL function.

Specified by:

getExpression in interface SQLMethod

Parameters:

stmt - SQLStatement that this expression is for

expr - The expression that it is invoked on

args - Arguments passed in

Returns:

The SQL expression using the SQL function