SQL is not null
Created By: chatGPT
SQL provides a way to filter records based on certain conditions. One common condition is to check if a value is not null. This is crucial when you want to exclude records that have undefined or missing values in a specific column. Here’s how you can use the IS NOT NULL condition in a SQL query.
SELECT * FROM employees WHERE email IS NOT NULL;In this example, we are selecting all records from the employees table where the email column has a value that is not null. This means only employees with an email address will be returned in the result set.
SELECT first_name, last_name FROM customers WHERE phone_number IS NOT NULL;You can combine the IS NOT NULL condition with other conditions using the AND operator to refine your query further. For instance, if you want to find employees who have both an email address and a department assigned, you could write:
SELECT * FROM employees WHERE email IS NOT NULL AND department IS NOT NULL;Additionally, using IS NOT NULL is not just limited to SELECT queries. You can also use it in UPDATE or DELETE statements to ensure you are modifying or removing records that meet certain criteria.
DELETE FROM orders WHERE fulfillment_date IS NOT NULL;