'SQL How to get categories that don't contain products?

SELECT DISTINCT {c2.name} 
FROM 
    {BrandCategory AS c  
    JOIN CategoryProductRelation AS c2p  
    ON  {c.pk} = {c2p.source}  
    JOIN Product AS p  
    ON  {c2p.target} = {p.pk}  
    JOIN CategoryProductRelation AS c2p2  
    ON  {p.pk} = {c2p2.target}  
    JOIN TaxonomyCategory AS c2 ON {c2.pk} = {c2p2.source} 
    JOIN CatalogVersion AS cat 
    ON {c.catalogVersion} = {cat.PK}} 
WHERE 
    {c.code} = 'brand-MCH' 
    AND{cat.version} = 'Online' 
    AND {c2.code} NOT LIKE'%webFamily%' 
    AND {p.code} IN ('35365','34299')

Above query pulls out Taxonomy Categories that contain products '35365' and '34299'

Result:
Passenger
Touring
All-Season
Truck

All Categories:
All-Season
Performance
Passenger
Winter
Touring
Summer
Truck
All-Terrain
Competition
Lawn

Now requirement is to pull out all other Taxonomy Categories, meaning those categories that dont contain products '35365' and '34299'

Attempt 1:(Fail)(NOT IN)

SELECT  DISTINCT {c2.name}
    FROM  {BrandCategory AS c
    JOIN  CategoryProductRelation AS c2p  ON {c.pk} = {c2p.source}
    JOIN  Product AS p  ON {c2p.target} = {p.pk}
    JOIN  CategoryProductRelation AS c2p2  ON {p.pk} = {c2p2.target}
    JOIN  TaxonomyCategory AS c2  ON {c2.pk} = {c2p2.source}
    JOIN  CatalogVersion AS cat  ON {c.catalogVersion} = {cat.PK}}
    WHERE  {c.code} = 'brand-MCH' AND{cat.version} = 'Online'
      AND  {c2.code} NOT LIKE'%webFamily%'
      AND  {p.code} NOT IN ('35365','34299')

Attempt 2:(Fail)(NOT EXISTS)

SELECT  DISTINCT {c2.name}
    FROM  {BrandCategory AS c
    JOIN  CategoryProductRelation AS c2p  ON {c.pk} = {c2p.source}
    JOIN  Product AS p  ON {c2p.target} = {p.pk}
    JOIN  CategoryProductRelation AS c2p2  ON {p.pk} = {c2p2.target}
    JOIN  TaxonomyCategory AS c2  ON {c2.pk} = {c2p2.source}
    JOIN  CatalogVersion AS cat  ON {c.catalogVersion} = {cat.PK}}
    WHERE  {c.code} = 'brand-MCH' AND{cat.version} = 'Online'
      AND  {c2.code} NOT LIKE'%webFamily%'
      AND  {c2.code}
      AND  NOT EXISTS ({{
        SELECT  DISTINCT {c3.name}
            FROM  {BrandCategory AS c
            JOIN  CategoryProductRelation AS c2p  ON {c.pk} = {c2p.source}
            JOIN  Product AS p  ON {c2p.target} = {p.pk}
            JOIN  CategoryProductRelation AS c2p2  ON {p.pk} = {c2p2.target}
            JOIN  TaxonomyCategory AS c3  ON {c3.pk} = {c2p2.source}
            JOIN  CatalogVersion AS cat  ON {c.catalogVersion} = {cat.PK}}
            WHERE  {c3.name}={c2.name}
              AND  {c.code} = 'brand-MCH' AND{cat.version} = 'Online'
              AND  {c3.code} NOT LIKE'%webFamily%'
              AND  {p.code} IN ('35365','34299')}}
                      )

Attempt 3:(Fail)(NOT IN SUBQUERY)

SELECT  DISTINCT {c2.name}
    FROM  {BrandCategory AS c
    JOIN  CategoryProductRelation AS c2p  ON {c.pk} = {c2p.source}
    JOIN  Product AS p  ON {c2p.target} = {p.pk}
    JOIN  CategoryProductRelation AS c2p2  ON {p.pk} = {c2p2.target}
    JOIN  TaxonomyCategory AS c2  ON {c2.pk} = {c2p2.source}
    JOIN  CatalogVersion AS cat  ON {c.catalogVersion} = {cat.PK}}
    WHERE  {c.code} = 'brand-MCH' AND{cat.version} = 'Online'
      AND  {c2.code} NOT LIKE'%webFamily%'
      AND  {c2.name} NOT IN ({{
        SELECT  DISTINCT {c2.name}
            FROM  {BrandCategory AS c
            JOIN  CategoryProductRelation AS c2p  ON {c.pk} = {c2p.source}
            JOIN  Product AS p  ON {c2p.target} = {p.pk}
            JOIN  CategoryProductRelation AS c2p2  ON {p.pk} = {c2p2.target}
            JOIN  TaxonomyCategory AS c2  ON {c2.pk} = {c2p2.source}
            JOIN  CatalogVersion AS cat  ON {c.catalogVersion} = {cat.PK}}
            WHERE  {c.code} = 'brand-MCH' AND{cat.version} = 'Online'
              AND  {c2.code} NOT LIKE'%webFamily%'
              AND  {p.code} IN ('35365','34299')}}
                          )

...

Result:
All-Season
Performance
Passenger
Winter
Touring
Summer
Truck
All-Terrain
Competition
Lawn

Expected:
Performance
Winter
Summer
All-Terrain
Competition
Lawn

Please help out on getting those categories that don't contain with a optimal query keeping performance in check.

Also, if there is a way to get all categories with some flag in result to differentiate what product contains true or not, that would be absolute Gold, because here we are hitting DB twice to get categories that contains and then categories that don't contain through a on-demand call

Note: These are essentially SQL queries, but just slightly modified with those braces to support Flexible Search Query format in Hybris Framework

mysqlsql-serverperformancequery-performanceinverse


Solution 1:[1]

Queries-
1. Using NOT IN-
SELECT {c.code} FROM {Product as p join CategoryProductRelation as c2p on {c2p.target} = {p.pk} join Category as c on {c2p.source} = {c.pk}} WHERE {p.code} NOT IN ('35365','34299')

  1. Using NOT EXISTS-
    SELECT {c.code} FROM {CategoryProductRelation as c2p join Category as c on {c2p.source} = {c.pk}} WHERE NOT EXISTS ({{SELECT {p.code} FROM {Product as p} WHERE {p.code} IN ('35365','34299') and {c2p.target}={p.pk}}})

  2. Using subquery-
    SELECT {c.code} FROM {Product as p join CategoryProductRelation as c2p on {c2p.target} = {p.pk} join Category as c on {c2p.source} = {c.pk}} WHERE {p.pk} IN ({{SELECT {pk} FROM {Product} WHERE {code} IN ('35365','34299')}})

Solution 2:[2]

Start by seeing if the NOT EXISTS and NOT IN give the right values.

For EXISTS, do not bother with DISTINCT, nor with specifying a column. This suffices:

NOT EXISTS ( SELECT 1 FROM ... )

Rip out all JOIN that are not relevant to the problem. This will make it easier to see what is wrong.

What are the braces? Perhaps you should remove the [mysql] tag?

Solution 3:[3]

I think it's too easy :

use NORTHWND

-- first :query to select categories don't have any product

select Categories.CategoryID , CategoryName , ProductID, ProductName from Products right join Categories on Categories.CategoryID = Products.CategoryID where (ProductID is null)

--second : query to select products don't follow any category

select Categories.CategoryID , CategoryName , ProductID, ProductName from Products left join Categories on Categories.CategoryID = Products.CategoryID where (Categories.CategoryID is null)

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1
Solution 2 Rick James
Solution 3 Ahmed Mohamed Hassan

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