<div><br></div> "Group by" is implicit in rules, just by writing patterns in order. So, if you write a rule that starts with Customer(), it will automatically do a "group by" customer:<div><br></div><div>
when</div><div> Customer(...)</div><div> ...</div><div>then</div><div><br></div><div> "Distinct" is a bit problematic, as we have no explicit distinct functionality (I have an open ticket for that: <a href="https://jira.jboss.org/browse/JBRULES-2640">https://jira.jboss.org/browse/JBRULES-2640</a>) but in some cases you can use collectSet for similar results.</div>
<div><br></div><div> In your case, you can go with Wolfgang's suggestion, or using accumulate:</div><div><br></div><div>declare ReportForDate</div><div> custNo : String </div><div> date : Date</div><div>end</div>
<div><br></div><div>rule "insert report dates"</div><div> salience 10</div><div> dialect "mvel"</div><div>when</div><div> Customer( $pd : purchaseDate, $custNo : custNo )</div><div> not( ReportForDate( custNo == $custNo, date == $pd ) )</div>
<div>then</div><div> with( $r = new ReportDate() ) {</div><div> custNo = $custNo,</div><div> date == $pd</div><div> }</div><div> insert( $r );</div><div>end</div><div><br></div><div>rule "customers that purchased more than 100 on a given date"</div>
<div>when</div><div> ReportDate( $pd: date, $cn : custNo )</div><div> Number( $total : doubleValue > 100 ) from accumulate(</div><div> Customer( $custNo == $cn, purchaseDate == $pd, $am : amount ),</div><div>
sum( $am ) )</div><div>then</div><div> // do something as the customer $cn purchased $total on $pd</div><div>end</div><div><br></div><div> Edson<br><br><div class="gmail_quote">2010/8/10 vijrams <span dir="ltr"><<a href="mailto:mailrvijay@gmail.com">mailrvijay@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><br>
Hi<br>
<br>
i have an object customer (purchaseDate, CustNo, Amount)<br>
<br>
i need to find the customers who purchased more than X amount in each date)<br>
ie group by customer then group by date and then sum of amount<br>
<br>
<br>
how do you write a rule for this<br>
<br>
thanks<br>
Vijay<br>
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</font></blockquote></div><br><br clear="all"><br>-- <br> Edson Tirelli<br> JBoss Drools Core Development<br> JBoss by Red Hat @ <a href="http://www.jboss.com">www.jboss.com</a><br>
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