Unmatched Query

When one is working with large amounts of data, what is the quickest way of displaying rows not found when comparing two tables, without doing the following:

SELECT table1.field1 FROM Table1 WHERE Table1.field1 NOT IN (SELECT Table2.field1 FROM Table2)

When possible, you should always use the exists clause instead of the IN clause. Exists is more efficient.

 So select * from table1 wherenot exists(select * from table2 wheretable1.col1 = table2.col2)
Share the Post:
Share on facebook
Share on twitter
Share on linkedin


The Latest

your company's audio

4 Areas of Your Company Where Your Audio Really Matters

Your company probably relies on audio more than you realize. Whether you’re creating a spoken text message to a colleague or giving a speech, you want your audio to shine. Otherwise, you could cause avoidable friction points and potentially hurt your brand reputation. For example, let’s say you create a

chrome os developer mode

How to Turn on Chrome OS Developer Mode

Google’s Chrome OS is a popular operating system that is widely used on Chromebooks and other devices. While it is designed to be simple and user-friendly, there are times when users may want to access additional features and functionality. One way to do this is by turning on Chrome OS

homes in the real estate industry

Exploring the Latest Tech Trends Impacting the Real Estate Industry

The real estate industry is changing thanks to the newest technological advancements. These new developments — from blockchain and AI to virtual reality and 3D printing — are poised to change how we buy and sell homes. Real estate brokers, buyers, sellers, wholesale real estate professionals, fix and flippers, and beyond may