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POFind difference between two fields as columns in a table
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  1. POFind difference between two fields as columns in a table
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    copied!<p>I have the following sql below</p> <pre><code>SELECT ttstudent.ttstudentid, ttstudent.studentid, ttstudent.subjectid, ttstudent.classnumber, ttstudent.classid, concat(student.fn, " ", student.sn) AS Student, SUM(If(ondemand.cycle="Feb7" and ondemand.type="Numeracy", ondemand.Score, NULL)) AS `Yr7 Feb`, SUM(If(ondemand.cycle="Jul7" and ondemand.type="Numeracy", ondemand.Score, NULL)) AS `Yr7 July`, SUM(If(ondemand.cycle="Feb8" and ondemand.type="Numeracy", ondemand.Score, NULL)) AS `Yr8 Feb`, SUM(If(ondemand.cycle="Jul8" and ondemand.type="Numeracy", ondemand.Score, NULL)) AS `Yr8 July`, SUM(If(ondemand.cycle="Feb9" and ondemand.type="Numeracy", ondemand.Score, NULL)) AS `Yr9 Feb`, SUM(If(ondemand.cycle="Jul9" and ondemand.type="Numeracy", ondemand.Score, NULL)) AS `Yr9 July`, SUM(If(ondemand.cycle="Feb10" and ondemand.type="Numeracy", ondemand.Score, NULL)) AS `Yr10 Feb`, SUM(If(ondemand.cycle="Jul10" and ondemand.type="Numeracy", ondemand.Score, NULL)) AS `Yr10 Aug`, ondemand.Student_ID FROM ttstudent INNER JOIN student ON ttstudent.studentid = student.code INNER JOIN ondemand ON ttstudent.studentid = ondemand.Student_ID GROUP BY ondemand.Student_ID </code></pre> <p>This generates for about 25 people a columnar list with the last column the calculated field that finds the difference between the last 2 values in the table. The scores are time stamped.</p> <pre><code>CODE |Year7Feb|Year7Jul|Year8Feb|Year8Jul|Year9Feb|Year9Jul| Year10Feb| Growth abe1 | 2.3 | 2.9 | | | | | | .6 bas1 | | | 3.5 | 3.7 | | | | .2 cod | | | | | | 4.5 | 5.2 | .7 </code></pre> <p>What I would like to do is a add another column which would take the last two scores from each user (whichever column it is in) and find the difference. I would call this column growth.</p> <p>I am struggling with what to use other than max. Any ideas?</p>
 

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