sql - 如何正确使用JOIN

Question

标签： sql

Answer 1

Your query basically looks right. However, if you want all rows in the first table, then use a LEFT JOIN:

SELECT pe.sku AS SKU, ev.value AS Description
FROM Product_Entity pe LEFT JOIN
     Entity_Varchar ev
     ON ev.entity_id = pe.entity_id AND
        ev.attribute_id = '73';

Rows that don't match will have NULL for the description.