WSO2 DAS SiddhiQL：初始化事件表并在之后更新

Question

我有一些相关的问题：

1. Fisrt，我想初始化一个事件表，其中包含默认值和100行，如下图所示：



1. 其次，初始化完成后，我想更新此表。查询1执行完成后，如何在同一执行计划中执行query2？

2. 要完成，我有一个'altitude'属性的事件。在我的执行计划中，对于每个事件，我想增加事件表的每一行count1，其中num列小于alitude。我试过了，但这并没有增加所有行的数量。

   FROM inputStream JOIN counterTable
   SELECT count1+1 as count1, altitude as tempNum
   update counterTable on counterTable.count1 < tempNum;
   
   FROM inputStream JOIN counterTable
   SELECT counterTable.num as theAltitude, counterTable.count1 as countAltitude
   INSERT INTO outputStream;
   

Answer 1

1. 如果要在每次部署执行计划时进行初始化，则应使用内存事件表（如下所示）。否则，您只需使用RDBMS event table，它已经初始化。

2. 查询将按照已定义的顺序运行，但该过程将按照每个事件发生（而不是作为批处理，即如果有两个查询从inputStream消耗，则事件1进入时inputStream它转到查询1，然后查询2，然后只有事件2将被消耗..）。

3. 请参阅以下代码段;

   /* Define the trigger to be used with initialization */
   define trigger triggerStream at 'start';
   
   /* Define streams */
   define stream inputStream (altitude int);
   define stream outputStream (theAltitude long, countAltitude int);
   
   /* Define table */
   define table counterTable (num long, count1 int, count2 int, tempNum int);
   
   /* Iterate and generate 100 events */
   from triggerStream[count() < 100]
   insert into triggerStream;
   
   /* Using above 100 events, initialize the event table */
   from triggerStream
   select count() as num, 0 as count1, 0 as count2, 0 as tempNum
   insert into counterTable;
   
   /* Perform the update logic here */
   from inputStream as i join counterTable as c
       on c.count1 < i.altitude
   select c.num, (c.count1 + 1) as count1, c.count2, altitude as tempNum
   insert into updateStream;
   
   from updateStream
   insert overwrite counterTable
       on counterTable.num == num;
   
   /* Join the table and get the updated results */
   from inputStream join counterTable as c
   select c.num as theAltitude, c.count1 as countAltitude
   insert into outputStream;
   

Answer 2

表值可以按如下方式初始化。

@info(name='initialize table values')
from inputStream[count()==1]
select 1 as id, 0 as counter1, 0 as counter2, 0 as counter3
insert into counterTable;