thank you very much

yes your query is shorter and faster than main?

there is another problem?

I want result to be like this

time avg of(val)

11:15:00 34.5(it should include avg between 11 to 11:15)

11:30:00 43.6(it should include avg between 11:15 to 11:30)

that means time should start from 11.15 in first column it should contain avg of val between 11 to 11:15?......

1.how do preferred CTE in your query ? how to know which one works better than which ?is there any link that you can share?

I ALWAYS get confused while starting a new reporting project about using the CTE or temp table using case or if statement ? please reply

thank you once again