Question

Say I have a product_attribute table with the following rows:

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| product_attribute_id | product_id | name         | value     |
================================================================
| 1                    | 25         | Author       | John Doe  |
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| 2                    | 25         | Author       | Jane Doe  |
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| 3                    | 55         | Publisher    | ABC Corp  |
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| 4                    | 55         | Release Date | 20100125  |
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I’m looking into implementing Solr for full-text searching and I think this table potentially has important information that should be indexed. So, I think this table needs to be pivoted (using product_id as the pivot point) so I can combine it with other tables that have information that should be indexed.

Questions:

1. How do I pivot this in MySQL?
2. I do not know in advance what all the name/value pairs are going to be. Will this be a problem?
3. Some attributes have identical names (e.g. “Author” in the example above). Will this be a problem?

Answer 1

thats a pretty standard implementation

SELECT
product_id,
GROUP_CONCAT(if(name = 'Author', value, NULL)) AS 'Author',
GROUP_CONCAT(if(name = 'Publisher', value, NULL)) AS 'Publisher',
FROM product_attribute
GROUP BY product_id; 

you have to

select distinct(name) from product_attribute

so you can build the above query
but NO it will not work with identical names , GROUP_CONCAT will concat the values .

i ve seen an implementation which adds a column and populates it with increment values so that it can then pivot the table using variables and a counter. but i dont have that in mysql