Using SQL IN

SQL IN allows you to limit the result set in a specified value list. Here is the syntax of using SQL IN :

SELECT column_list  
FROM table  
WHERE column IN (value_list_expression)

The value_list_expression can be any constant value list or selection query which returns a list of value. Let take a look at SQL IN in the following examples. We will use two sample tables

employees table data

employee_id  name      department_id  job_id  salary 
-----------  --------  -------------  ------  -------
          1  jack                  1       1  3000.00
          2  mary                  2       2  2500.00
          3  newcomer         (NULL)       0  2000.00
          4  anna                  1       1  2800.00
          5  Tom                   2       2  2700.00
          6  foo                   3       3  4700.00

and departments table data

department_id  name                
-------------  --------------------
            1  Software Engineering
            2  Sale                
            3  Marketing           
            4  HR   

Here is an example of using SQL IN to retrieve employee which has salary is 2000 or 3000

SELECT name,salary  
FROM employees  
WHERE salary IN (2000,3000)

The output is

name      salary 
--------  -------
jack      3000.00
newcomer  2000.00

And here is another example of using SQL IN which retrieves all in employees in software engineering department:

SELECT name, salary  
FROM employees  
WHERE department_id IN (
    SELECT department_id 
    FROM departments 
    WHERE departments.name = 'Software Engineering'  
)

The database system returns two employees which work in software engineering department

name    salary 
------  -------
jack    3000.00
anna    2800.00