Linq The sum of hourly data?
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There are hourly data is captured in my table. I want to sum of these data for a day. For examle

this is my table data

    | date             | value |

    | 12.03.2010 01.pm |    10 |
    | 12.03.2010 02.pm |    20 |
    | 12.03.2010 03.pm |    15 |
    | 13.03.2010 04.pm |    15 |
    | 13.03.2010 05.pm |    25 |
    | 13.03.2010 08.pm |    35 |

And I want to get sum of values in a day.

    12.03.2010 total_usage = 45
    12.03.2010 total_usage = 75
    
I dont say write codes for me, I want a way, hint point or tutorial about this topic. How Can I do this. How can I get sum of hourly data in a day.

Thanks.
    