任務(wù)：將如下輸入XML變成如下輸出XML
輸入XML：
<employees><employee><id>001</id><name>張飛</name><age>28</age></employee><employee><id>002</id><name>關(guān)羽</name><age>29</age></employee><employee> <id>003</id><name>趙云</name><age>30</age></employee></employees>
輸出XML：
<summary><count>3</count><names>張飛,關(guān)羽,趙云,</names><maxAge>30</maxAge><avgAge>2.9E+1</avgAge></summary>
我們需要做一個(gè)Input節(jié)點(diǎn)和一個(gè)Output節(jié)點(diǎn)以及一個(gè)Comput節(jié)點(diǎn)，并設(shè)置Compute節(jié)點(diǎn)的ESQL如下：
CREATE COMPUTE MODULE flow_Compute
CREATE FUNCTION Main() RETURNS BOOLEAN
BEGIN
-- 員工總數(shù)
DECLARE Count INTEGER 0;
-- 得到XML中員工總數(shù)
SET Count=CARDINALITY(InputRoot.XML.employees.employee[]);
-- 員工姓名匯總
DECLARE Names CHARACTER;
SET Names='';
-- 最大年齡
DECLARE MaxAge INTEGER 0;
-- 年齡合計(jì)
DECLARE SumAge INTEGER 0;
-- 當(dāng)前年齡
DECLARE CurrAge INTEGER 0;
-- 循環(huán)變量
DECLARE I INTEGER 1;
WHILE I<=Count DO
-- 字符串拼接
SET Names=Names || InputRoot.XML.employees.employee[I].name ;
SET Names=Names || ',';
-- 字符串轉(zhuǎn)換成整數(shù)再進(jìn)行年齡合計(jì)
SET CurrAge = CAST(InputRoot.XML.employees.employee[I].age AS INTEGER);
SET SumAge=SumAge+CurrAge;
-- 得到最大年齡
IF MaxAge<CurrAge THEN
SET MaxAge=CurrAge;
END IF;
SET I=I+1;
END WHILE;
-- 平均年齡
DECLARE AvgAge FLOAT;
SET AvgAge=SumAge/Count;
-- 拼接輸出XML
SET OutputRoot.XML.summary.count=Count;
SET OutputRoot.XML.summary.names=Names;
SET OutputRoot.XML.summary.maxAge=MaxAge;
SET OutputRoot.XML.summary.avgAge=CAST(AvgAge AS CHARACTER);
RETURN TRUE;
END;
END MODULE;
本例工程下載地址：
http://www.tkk7.com/Files/heyang/ESqlTest0920_01.rar