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POCreate a Summary View in MySQL by pivoting row into dynamic number of columns
 

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    <p>I have a table in MySQL with the following fields:</p> <pre><code>id, company_name, year, state </code></pre> <p>There are multiple rows for the same customer and year, here is an example of the data:</p> <pre><code> id | company_name | year | state ---------------------------------------- 1 | companyA | 2008 | 1 2 | companyB | 2009 | 2 3 | companyC | 2010 | 3 4 | companyB | 2009 | 1 5 | companyC | NULL | 3 </code></pre> <p>I am trying to create a view from this table to show one company per row (i.e. <code>GROUP BY</code> pubco_name) where the state is the highest for a given year.</p> <p>Here is an example of the view I am trying to create:</p> <pre><code> id | cuompany_name | NULL | 2008 | 2009 | 2010 -------------------------------------------------- 1 | companyA | NULL | 1 | NULL | NULL 2 | companyB | NULL | 2 | NULL | NULL 3 | companyC | 3 | NULL | NULL | 3 </code></pre> <p>There is a lot more data than this, but you can see what I am trying to accomplish.</p> <p>I don't know how to select the max state for each year and group by pubco_name. Here is the SQL I have thus far (I think we need to use <code>CASE</code> and/or <code>sub-selects</code> here):</p> <pre><code>SELECT id, company_name, SUM(CASE WHEN year = 2008 THEN max(state) ELSE 0 END) AS 2008, SUM(CASE WHEN year = 2009 THEN max(state) ELSE 0 END) AS 2009, SUM(CASE WHEN year = 2010 THEN max(state) ELSE 0 END) AS 2010, SUM(CASE WHEN year = 2011 THEN max(state) ELSE 0 END) AS 2011, SUM(CASE WHEN year = 2012 THEN max(state) ELSE 0 END) AS 2012, SUM(CASE WHEN year = 2013 THEN max(state) ELSE 0 END) AS 2013 FROM tbl GROUP BY company_name ORDER BY id DESC </code></pre> <p>Appreciate your help and thanks in advance.</p>
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    1. CO9 times out of 10 issues of data display are best handled at the application level.
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    2. CO@Strawberry you recommend PHP?
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    3. COI do - but only because that's the only application level code that I know!
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