PHP Reference Book Blog

PHP Reference: Beginner to Intermediate PHP5

It took a ton of googling, and it was really hard to find the answer. I had two tables, and wanted to do a MySQL Query that seems like a NOT IN between two tables. There are two tables with one unique field that is the same between the tables. The goal is to find the rows in the second table that are not found in the first table based upon the similar field.

I could attempt to explain this, but someone has already done a very good job of this, so I’d rather just provide a link to their content. The post is from the author of “High Performance MySQL”, Baron Schwartz, and covers writing an SQL Exclusion Join. The key area of interest is the section on LEFT OUTER joins. He offers this example query:

SELECT apples.Variety
FROM apples
    LEFT OUTER JOIN oranges
        ON apples.Price = oranges.Price
WHERE oranges.Price IS NULL

When in doubt, find someone smarter to answer the question for you. :) Thanks Baron!

Similar Posts:

Be Sociable, Share!
Tags:

Comments are closed.