Select from one table where not in another

Question

I\'m trying to find the rows that are in one table but not another, both tables are in different databases and also have different column names on the column that I\'m using

Answer 1

To expand on Johan's answer, if the part_num column in the sub-select can contain null values then the query will break.

To correct this, add a null check...

SELECT pm.id FROM r2r.partmaster pm
WHERE pm.id NOT IN 
      (SELECT pd.part_num FROM wpsapi4.product_details pd 
                  where pd.part_num is not null)

• Sorry but I couldn't add a comment as I don't have the rep!