SQLite IS NOT NULL

In SQLite, the NOT NULL operator is used to filter data in a SELECT statement based on the presence or absence of a value in a specific column. When used in a SELECT statement, the NOT NULL operator returns only those rows where the specified column has a non-null value.

Syntax

Here’s the basic syntax for using the NOT NULL operator in a SELECT statement:

SELECT column1, column2, ...
FROM table_name
WHERE column_name IS NOT NULL;

In this syntax, “column_name” is the name of the column for which you want to check the null value. When you use the IS NOT NULL operator, SQLite will return only those rows where the specified column has a non-null value.

Example

For example, let’s assume that you have a table named “customers” with the following columns: “customer_id”, “first_name”, “last_name”, and “email_address”. If you want to retrieve all rows where the email_address column has a non-null value, you can use the following SELECT statement:

SELECT customer_id, first_name, last_name
FROM customers
WHERE email_address IS NOT NULL;

This statement will return only those rows where the email_address column has a non-null value. Any rows with a null value in the email_address column will be excluded from the result set.

In conclusion, the NOT NULL operator in a SELECT statement is a useful tool for filtering data based on the presence or absence of a value in a specific column. It can help you retrieve only the data you need and exclude any rows that don’t meet your criteria.