否定 "every" 语句？ WSO2 CEP / Siddhi

Question

有没有简单的方法可以否定"every"语句？我正在尝试实施一种检查传入采购订单和申请的控制工具。对于每个采购订单 (PO)，必须先创建一个申请 (REQ)。以下代码检测 PO/REQ-pairs 匹配（正），但我需要所有没有相应 REQ（负）的采购订单。

from every a1 = PO -> b1 = REQ[a1.ITEM_ID == b1.ITEM_ID and a1.QUANTITY == b1.QUANTITY and a1.CREATED_BY == b1.CREATED_BY] within 1 day select 'No REQ created before' as ALERT_MESSAGE insert into ALERT;

Answer 1

可以参考sample on detecting non-occurrences with patterns。但是，由于您要检查 REQ 事件是否在 PO 事件之前发生，您可能需要使用内存中的事件表来满足您的要求。请参考以下关于使用内存表实现相同目标的示例；

@Import('REQStream:1.0.0')
define stream REQ (ITEM_ID int, QUANTITY int, CREATED_BY string);

@Import('POStream:1.0.0')
define stream PO (ITEM_ID int, QUANTITY int, CREATED_BY string);

@Export('ALERTStream:1.0.0')
define stream ALERT (ITEM_ID int, ALERT string);

define table REQ_TABLE (ITEM_ID int, QUANTITY int, CREATED_BY string);

define trigger DAILY_TRIGGER at every 1 day;

from REQ
insert into REQ_TABLE;

-- check whether request exists before the purchase
from PO[not((REQ_TABLE.ITEM_ID == ITEM_ID and REQ_TABLE.QUANTITY == QUANTITY and REQ_TABLE.CREATED_BY == CREATED_BY) in REQ_TABLE)] 
select ITEM_ID, 'No REQ created before' as ALERT
insert into ALERT;

-- purge reauests table daily
from DAILY_TRIGGER join REQ_TABLE
select REQ_TABLE.ITEM_ID, REQ_TABLE.QUANTITY, REQ_TABLE.CREATED_BY
insert into PURGE_STREAM;

-- if there's no matching purchase order came up for previous day
from PURGE_STREAM
select ITEM_ID, 'No purchase order came up for a day' as ALERT
insert into ALERT;

from PO
insert into DEL_STREAM;

from PURGE_STREAM
insert into DEL_STREAM;

-- delete corresponding request from table
from DEL_STREAM 
delete REQ_TABLE
    on REQ_TABLE.ITEM_ID == ITEM_ID and REQ_TABLE.QUANTITY == QUANTITY and REQ_TABLE.CREATED_BY == CREATED_BY;

否定 "every" 语句？ WSO2 CEP / Siddhi

Negation for "every" statement? WSO2 CEP / Siddhi

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