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POMySQL, three tables: Select all rows in right table including rows that are not mapped in middle table
 

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  1. POMySQL, three tables: Select all rows in right table including rows that are not mapped in middle table
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    <p>My schema are as follows:</p> <pre><code>Sites S | S.Id | S.Url | | 1 | a.com | | 2 | b.edu | | 3 | c.org | SiteFeatures SF | SF.SiteId | SF.FeatureID | | 1 | 1 | | 1 | 2 | | 1 | 3 | | 2 | 1 | | 2 | 2 | | 2 | 3 | | 2 | 4 | | 3 | 2 | | 3 | 3 | Features F | F.Id | F.FeatureName | | 1 | apple | | 2 | banana | | 3 | cherry | | 4 | diaper | | 5 | egg | | 6 | fish | </code></pre> <p>I want to select all sites, mapped to all features, including features missing from the middle join table. For features that have no entry in the join table, I want to display a "0". For features that exist in the join table, I want a "1".</p> <p>So the results will look like this:</p> <pre><code>| SiteId | SiteURL | FeatureName | Enabled | | 1 | a.com | apple | 1 | | 1 | a.com | banana | 1 | | 1 | a.com | cherry | 1 | | 1 | a.com | diaper | 0 | | 1 | a.com | egg | 0 | | 1 | a.com | fish | 0 | | 2 | b.edu | apple | 1 | | 2 | b.edu | banana | 1 | | 2 | b.edu | cherry | 1 | | 2 | b.edu | diaper | 1 | | 2 | b.edu | egg | 0 | | 2 | b.edu | fish | 0 | | 3 | c.org | apple | 0 | | 3 | c.org | banana | 1 | | 3 | c.org | cherry | 0 | | 3 | c.org | diaper | 1 | | 3 | c.org | egg | 0 | | 3 | c.org | fish | 0 | </code></pre> <p>-- EDIT -- Additional Information.</p> <p>I originally created a pivot table using this article:</p> <p><a href="http://dev.mysql.com/tech-resources/articles/wizard/print_version.html" rel="nofollow">http://dev.mysql.com/tech-resources/articles/wizard/print_version.html</a></p> <p>Based on that article, I wrote a SQL statement to dynamically generate a SQL query that generates the pivot table.</p> <p>That statement looked like this:</p> <pre><code>SELECT CONCAT( ", SUM(IF( F.FeatureName = '" , F.FeatureName , "', 1,0 ))" , " AS `" , F.FeatureName , "` ") AS CutNPaste FROM Features F WHERE 1 GROUP BY F.FeatureName ORDER BY F.FeatureName -- END </code></pre> <p>The second SQL statement was as follows:</p> <pre><code>SELECT , S.Url /* This section was dynamically generated, and copied into this SELECT statement */ , SUM(IF( F.FeatureName = 'apple', 1,0 )) AS `apple` , SUM(IF( F.FeatureName = 'banana', 1,0 )) AS `banana` , SUM(IF( F.FeatureName = 'cherry', 1,0 )) AS `cherry` , SUM(IF( F.FeatureName = 'diaper', 1,0 )) AS `diaper` , SUM(IF( F.FeatureName = 'egg', 1,0 )) AS `egg` , SUM(IF( F.FeatureName = 'fish', 1,0 )) AS `fish` /* END of dynamic part */ FROM Sites S LEFT OUTER JOIN SiteFeatures SF ON S.Id = SF.SiteId LEFT OUTER JOIN Features F ON SF.FeatureId = F.Id WHERE 1 AND SF.FeatureId = F.Id AND S.Enabled = 1 GROUP BY S.Url -- END </code></pre> <p>The results looked like this:</p> <pre><code>| Url | apple | banana | cherry | diaper | egg | fish | | a.com | 1 | 1 | 1 | 0 | 0 | 0 | | b.edu | 1 | 1 | 1 | 1 | 0 | 0 | | c.org | 0 | 1 | 0 | 1 | 0 | 0 | </code></pre> <p>I tried to repurpose the SQL and the concepts in these two statements, but I am at a loss.</p>
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      1. POMySQL, three tables: Select all rows in right table including rows that are not mapped in middle table
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    1. COWhat have you tried already - it will help you learn and understand if you have a pop and post your results, we can then help with where you are going wrong, and give you some pointers..
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    2. COI didn't post what I've tried only because it is rather a mess, and very verbose, and would require me to heavily clean it up. But I'll do that and post back.
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