Examples of SQLite EXCEPT Operator

To understand the EXCEPT Operator in a better we need 2 table on which we will perform some operations and queries for good understanding. Here we have 2 tables called departments and employee table. If you don’t know How to Create a table in SQLite then refer this.

The department table consist of dept_id and dept_name as Columns. After inserting some data into the table the department table looks:

The employee table consist of dept_id,emp_id, first_name, and last_name as Columns. After inserting some data into the table the department table looks:

Example 1: EXCEPT Operator With Single Expression

Let’s Find all department IDs present in the ‘department’ table but lacking any associated employees in the ‘employee‘ table. In this example we are going to retrieve only single expression from the table.

Query:

SELECT  dept_id
FROM department
EXCEPT
SELECT emp_id
FROM employee;

Output:

Explanation: In the above Query, We have fetch the department Id and employee id from the department and employee table on which EXCEPT operator is applied. However the employee id is not going to. In the output you can see that six rows are fetched and the column retrieved is department id that is resulted from the first select statement.

Example 2: EXCEPT Operator With Multiple Expression

Let’s find out all the employees first name and lastname frIn this example we are going to retrieve multiple expressions from the tables.

Query:

SELECT last_name, first_name 
FROM employee
EXCEPT
SELECT dept_id,dept_name
FROM department;

Output:

Explanation: In the above Query, We have fetch the last name, first name from the employee table and however the department id and department name are not going to fetch as the EXCEPT operator is applied. As we have learnt that EXCEPT operator .You can see that last name and first name columns are retrieved from the employee table as it is the first select statement.

SQLite is a server-less database engine written in C programming language. It is developed by D. Richard Hipp in the year 2000. The main motive for developing SQLite is to escape from complex database engines like MySQL etc. It has become one of the most popular database engines as we use it in Television, Mobile Phones, Web browsers, and many more. It is written simply so that it can be embedded into other applications.

In this article, you will learn about the SQLite Except operator, its working, and its functionality by using some examples. We will perform various queries with the practical implementation for an in-depth understanding of the article.