Esper epl语句实验

Posted 2020-09-30 gccbuaa

基础代码见下，下文列举的实验都是在此程序基础上改动。

all,snapshot,first

String epl = "select * from appTable.win:time(5 sec) output all every 2 seconds";
能够看到。输出时将事件从队列中移除。
已经输出的下次不再输出。

================
newEventName:appTable	name:0	age:0
newEventName:appTable	name:1	age:1
================
newEventName:appTable	name:2	age:2
newEventName:appTable	name:3	age:3
================
newEventName:appTable	name:4	age:4
newEventName:appTable	name:5	age:5
================

String epl = "select * from appTable.win:time(5 sec) output snapshot every 2 seconds";
输出的是快照，事件不从队列中移除。
================
newEventName:appTable	name:0	age:0
newEventName:appTable	name:1	age:1
newEventName:appTable	name:2	age:2
================
newEventName:appTable	name:0	age:0
newEventName:appTable	name:1	age:1
newEventName:appTable	name:2	age:2
newEventName:appTable	name:3	age:3
newEventName:appTable	name:4	age:4
================
newEventName:appTable	name:2	age:2
newEventName:appTable	name:3	age:3
newEventName:appTable	name:4	age:4
newEventName:appTable	name:5	age:5
================

String epl = "select * from appTable.win:time(5 sec) output first every 2 seconds";
仅仅输出进入窗体的第一条数据。

================
newEventName:appTable	name:0	age:0
================
newEventName:appTable	name:3	age:3
================
newEventName:appTable	name:5	age:5
================
newEventName:appTable	name:7	age:7
================

insert前后的时间窗体

String epl2 = "insert into appTable2 select t.id as id, t.price as price from appTable.win:time(5 sec) as t output all every 1 seconds";
String epl3 = "select * from appTable2.win:time(5 sec) output all every 5 seconds";	
为epl3配置监听。
能够看到。第一个5秒就有输出。

第1秒
第2秒
第3秒
第4秒
第5秒
newEventName:appTable2	name:0	age:0
newEventName:appTable2	name:1	age:1
newEventName:appTable2	name:2	age:2
newEventName:appTable2	name:3	age:3
newEventName:appTable2	name:4	age:4
================
第6秒
第7秒
第8秒
第9秒
第10秒
newEventName:appTable2	name:5	age:5
newEventName:appTable2	name:6	age:6
newEventName:appTable2	name:7	age:7
newEventName:appTable2	name:8	age:8
newEventName:appTable2	name:9	age:9
================
第11秒

String epl2 = "insert into appTable2 select t.id as id, t.price as price from appTable.win:time(5 sec) as t output all every 5 seconds";
String epl3 = "select * from appTable2.win:time(5 sec) output all every 5 seconds";	
为epl3配置监听。
能够看到，第二个5秒才有输出。

第1秒
第2秒
第3秒
第4秒
第5秒
第6秒
第7秒
第8秒
第9秒
newEventName:appTable2	name:0	age:0
newEventName:appTable2	name:1	age:1
newEventName:appTable2	name:2	age:2
newEventName:appTable2	name:3	age:3
newEventName:appTable2	name:4	age:4
================
第10秒
第11秒