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POSQL Query Get Max Value At Occured Date
 

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    <p>So we are doing some traffic reporting in our department. Therefore we got a table named traffic_report, which is build up like</p> <pre><code>╔════════════════╦═══════════╦═════════════════════╦═════════════╦═════════════╗ ║ hostname ║ interface ║ date_gmt ║ intraf_mpbs ║ outraf_mbps ║ ╠════════════════╬═══════════╬═════════════════════╬═════════════╬═════════════╣ ║ my-machine.com ║ NIC-5 ║ 2013-09-18 09:55:00 ║ 32 ║ 22 ║ ║ my-machine.com ║ NIC-5 ║ 2013-09-17 08:25:00 ║ 55 ║ 72 ║ ║ my-machine.com ║ NIC-5 ║ 2013-09-16 05:12:00 ║ 65 ║ 2 ║ ║ my-machine.com ║ NIC-5 ║ 2013-09-15 04:46:00 ║ 43 ║ 5 ║ ║ my-machine.com ║ NIC-5 ║ 2013-09-14 12:02:00 ║ 22 ║ 21 ║ ║ my-machine.com ║ NIC-5 ║ 2013-09-13 22:13:00 ║ 66 ║ 64 ║ ╚════════════════╩═══════════╩═════════════════════╩═════════════╩═════════════╝ </code></pre> <p>I'd like to fetch the maximum of the traffic in and traffic out at the occured date. My approach doing so is like this</p> <pre><code>SELECT hostname, interface, date_gmt, max(intraf_mbps) as max_in, max(outtraf_mbps) as max_out FROM traffic_report GROUP by hostname, interface </code></pre> <p>The approach produces a table like this</p> <pre><code>╔════════════════╦════════════╦═════════════════════╦════════╦═════════╗ ║ hostname ║ interface ║ date_gmt ║ max_in ║ max_out ║ ╠════════════════╬════════════╬═════════════════════╬════════╬═════════╣ ║ my-machine.com ║ NIC-5 ║ 2013-09-18 09:55:00 ║ 66 ║ 72 ║ ╚════════════════╩════════════╩═════════════════════╩════════╩═════════╝ </code></pre> <p>The problem is, the date_gmt displayed is just the date of the first record entered to the table.</p> <p>How do I instruct SQL to display me the date_gmt at which the max(intraf_mbps) occured?</p>
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    1. USBen Matheja
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    1. COwhat if max_in is on another day as max_out
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      1. USjuergen d
    2. COthat will be most likely true. It would be enough at this point to get one of the correct timestamps
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      1. USBen Matheja
    3. COThere is not a unique 'max data', perhaps they are several dates with same max traffic. You can get max traffic in a correlated subquery and filter for records with this traffic. It is a dirty solution, but mysql don't support analytic functions either ranks.
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      1. USdani herrera
 

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