将列分组为行SQL

Question

I am trying to group feature and value all on one line. Someone recommended GROUP_CONCAT but when I do that I lose all my other products. Here is the SQL call I currently have

SELECT ps_product_lang.name, CONCAT(ps_feature_lang.name) AS feature, ps_feature_value_lang.value  FROM ps_product LEFT JOIN ps_product_lang ON ps_product_lang.id_product = ps_product.id_product LEFT JOIN ps_feature_product ON ps_feature_product.id_product = ps_product.id_product LEFT JOIN ps_feature_lang ON ps_feature_lang.id_feature = ps_feature_product.id_feature LEFT JOIN ps_feature_value_lang ON ps_feature_value_lang.id_feature_value = ps_feature_product.id_feature_value

which gives me a return like this

name                 feature    value
MRO Plus Heavy Pad       Height 5
MRO Plus Heavy Pad       Width  12
MRO Plus Heavy Pad       Depth  13
MRO Plus Heavy Pad       Weight 15
ENV810™ Sorbent Boom     Height 88
ENV810™ Sorbent Booms    Width  50
ENV810™ Sorbent Booms    Depth  23
ENV810™ Sorbent Booms    Weight 45
ENV510™ Sorbent Booms    NULL   NULL
MRO Plus Medium Pad      NULL   NULL

When I try GROUP_CONCAT my results looks like this.

Name                Feature                                                 Value
MRO Plus Heavy Pad  Height,Width,Depth,Weight,Height,Width,Depth,Weigh...   5,12,13,15,88,50,23,45

Is there a way in MySQL to get it to look like this

Name                    Feature                           Value
MRO Plus Heavy Pad      Height, Width, Depth, Weight      5, 12, 13, 15
ENV810 Sorbent Boom     Height, Width, Depth, Weight      88, 50, 23, 45
ENV510 Sorbent Boom     Null                              Null
MRO Plus Medium pad     Null                              Null

Any help would be greatly appreciated!

Answer 1

The GROUP_CONCAT is a MySQL specific aggregate function , which works with the GROUP BY clause. You have to specify the column with the GROUP_BY clause at the end of your query to make it work.

Sample:

SELECT ps_product_lang.name, GROUP_CONCAT(ps_feature_lang.name) AS feature, ps_feature_value_lang.value FROM ps_product LEFT JOIN ps_product_lang ON ps_product_lang.id_product = ps_product.id_product LEFT JOIN ps_feature_product ON ps_feature_product.id_product = ps_product.id_product LEFT JOIN ps_feature_lang ON ps_feature_lang.id_feature = ps_feature_product.id_feature LEFT JOIN ps_feature_value_lang ON ps_feature_value_lang.id_feature_value = ps_feature_product.id_feature_value GROUP BY ps_product_lang.name